Afleveringen
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This Real Science Exchange podcast episode was recorded during a webinar from Balchem’s Real Science Lecture Series. You can find it at balchem.com/realscience.
Feeding behavior of dairy cows is inherently tied to their dry matter intake (DMI) which is tied to milk production. If we want to change a cow’s DMI, it must be mediated by changing her feeding behavior. (00:23)
In a multi-variable analysis, Dr. DeVries found that DMI was most associated with feeding time and meal frequency. It’s important to allow the cow to maximize the amount of time she can spend at the bunk eating, as well as the number of times she can get to the bunk each day. In one study, about 30% of the variability in milk fat content in cows on the same diet was explained by their meal frequency, where cows who had more meals per day had higher milk fat. Dr. DeVries also talks about the impacts of feeding behavior on cow efficiency and rumen dynamics. (2:13)
As soon as a cow sorts the TMR put in front of her, she consumes a diet that’s variable in composition to what we expect. Cows who sorted against long feed particles had lower milk fat and milk protein concentrations. In another study, Dr. DeVries retrospectively analyzed cows with a low vs high risk of ruminal acidosis. Cows in both groups had similar DMI but a tendency for high-risk cows to have lower milk yield and numerically lower milk fat. Combining these resulted in significantly lower fat-corrected milk for the high-risk cows. Given that the diets and DMI were similar, the difference was attributed to sorting, which can have quite negative impacts on individual and herd-level production. (10:00)
Cows spend nearly twice as much time ruminating as they do eating. Rumination reduces feed particle size and increases surface area, leading to increased rates of digestion and feed passage. In a recent study, Dr. DeVries’ group calculated the probability that cows were ruminating while lying down using automated monitoring data from previous experiments. Cows with a higher probability of ruminating while lying down had higher DMI, milk fat, and milk protein than cows who ruminated while standing. This highlights that cows need not only time to ruminate but also space for sufficient rest. (16:44)
Diets and diet composition should be formulated to encourage frequent meals, discourage sorting, and stimulate rumination. Forage management factors including forage quality, forage quantity, forage type (dry vs ensiled), and particle size all play important roles. In a study with fresh cows, Dr. DeVries’ lab fed two different particle sizes of straw: 5-8 cm vs 2-3 cm in length. While DMI was the same over the first 28 days of lactation, cows fed the long straw spent more time with rumen pH below 5.8 because they were sorting against the straw. This also resulted in a yield difference, as the short straw-fed cows produced about 165 pounds more milk over the first 28 days compared to the long straw group. Dr. DeVries also comments on the use of feed additives on rumen stability and feeding behavior (22:54)
More frequent feed delivery should generate more consistent consumption and better feeding behavior, and improve rumen health and milk component concentration. Shifting feed delivery away from return from milking, while still ensuring cows have abundant feed available, results in more consistent eating patterns. Dr. DeVries emphasizes that we push up feed to make sure it’s present at the bunk, not to stimulate cows to eat. We want to make sure that eating behavior is driven by the cow: when she's hungry and goes to the bunk, we need to make sure feed is there. (30:02)
Dr. DeVries indicates we want to minimize the time cows are without feed completely. An empty bunk overnight plus a little overcrowding resulted in negative impacts on rumen health, including more acidosis and reduced fiber digestibility. Increased competition in overcrowding scenarios results in cows having larger meals, eating faster, and likely having a larger negative ruminal impact. In another study, every four inches of increased bunk space was associated with about 0.06% greater milk fat. Herds with high de novo fat synthesis were 10 times more likely to have at least 18 inches of bunk space per cow. (40:04)
In closing, Dr. DeVries’ biggest takeaway is that how cows eat is just as important as the nutritional composition of the feed in ensuring cow health, efficiency, and production. Collectively, with good quality feed and good feeding management, we can gain optimal performance from those diets. Dr. DeVries ends by taking questions from the webinar audience. (43:40)
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Dr. Weiss and Dr. St-Pierre co-authored this episode’s journal club paper in Applied Animal Science (ARPAS Journal). Bill and Normand share a career-long interest in how feedstuffs and diet variation impact cows. (6:31)
Bill and Normand discuss sources of variation, which they divide into true variation and observer variation. True variation means the feed has changed: a different field, change during storage, etc. Observer variation includes sampling variation and analytical variation. Some feeds may exhibit a lot of true variation and others may exhibit a lot of observer variation. And some feeds are high in both types of variation. Highly variable feeds should be sampled more frequently. Some feeds are so consistent that using book values makes more sense than sending in samples for analysis. Bill and Normand go on to give some examples and share sampling and analysis tips for different types of feedstuffs. (12:41)
Bill would often be asked if users should continue to average new samples with older ones or just use the new numbers from the most recent sample. He and Normand debate the pros and cons of the two approaches as well as discuss the use of a weighted average where recent samples would be weighted to contribute more. (26:02)
Next, our guests discuss how multiple sources of a nutrient reduce the TMR variation for that specific nutrient. For example, alfalfa NDF is more variable than corn silage NDF on average. Yet if you use a blend of these two ingredients, you end up with less variation in NDF than if you used all corn silage. Normand details the mathematical concepts behind this relationship. Both Bill and Normand emphasize that diets must be made correctly for the best results. (32:26)
How do feedstuffs and diet variations impact cows? Both guests describe different experiments with variable protein and NDF concentrations in diets. Some were structured, like alternating 11% CP one day and 19% CP the next for three weeks. Some were random, like randomly alternating the NDF over a range of 20-29% with much higher variation than we’d ever see on-farm. The common thread for all these experiments is that the diet variations had almost no impact on the milk production of the cows. (38:04)
Clay asks how variation in dry matter might affect cows. Bill describes an experiment where the dry matter of silage was decreased by 10 units by adding water. Cows were fed the wet silage for three days, twice during a three-week study. To ensure feed was never limited, more as-fed feed was added when the wet silage was fed. It took a day for cows on the wet silage treatment to have the same dry matter intake (DMI) as the control cows and milk production dropped when DMI was lower. However, when switching abruptly back to the dry silage diet, DMI increased the day following the wet silage and stayed high for two days, so the cows made up for the lost milk production. Bill and Normand underline that it is critical for the cows not to run out of feed and described experiments where feed was more limiting, yielding less desirable outcomes. (46:17)
In the last part of the paper, our guests outlined seven research questions that they feel need to be answered. Normand shares that his number one question is how long will cows take to respond to a change in the major nutrients? He feels that we spend an inordinate amount of money on feedstuffs analysis, and there are some feeds we should analyze more and some feeds we should quit analyzing. Bill’s primary research question revolves around controlled variation. What happens if you change the ratio of corn silage and alfalfa once a week? Will that stimulate intake? Data from humans, pets, and zoo animals indicate that diet variation has a positive impact and Bill finds this area of research intriguing. (50:43)
In closing, Clay encourages listeners to read this paper (link below) and emphasizes the take-home messages regarding sampling and research questions. Normand advises that if you are sampling feed, take a minimum of two samples, and try as much as you can to separate observer variation from true variation. He also reminds listeners to concentrate on a few critical nutrients with more repeatability for analyses. Bill encourages nutritionists to sit down and think when they get new data - before they go to their computer to make a diet change. If something changed, why did it change, and is it real? Take time to think it through. (1:01:38)
You can find this episode’s journal club paper from Applied Animal Science here: https://www.appliedanimalscience.org/article/S2590-2865(24)00093-4/fulltext
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Zijn er afleveringen die ontbreken?
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This Real Science Exchange episode was recorded during a webinar, which was part of a series. Watch all the presentations from this series here: https://balchem.com/animal-nutrition-health/resources-categories/real-science-lecture-series/previous-lectures/page/10/
Early in lactation, the cow is incapable of eating enough to meet her dramatically increased requirements. As the cow’s intake decreases near calving, there are fewer nutrient contributions from dry matter intake and she must alter nutrient partitioning to meet her increased needs by mobilizing fat and muscle stores. (1:18)
Triglycerides from fat stores are broken down into non-esterified fatty acids (NEFA) and glycerol. NEFA has two different fates in the postpartum cow: to the mammary gland as a precursor for milk fat synthesis, or to the liver to be oxidized for energy production. Glycerol enters the gluconeogenic pathway in the liver as a glucose precursor. (4:41)
The capacity for the liver to use NEFA for energy is limited by the capacity of the TCA cycle. When the TCA cycle is at capacity, excess NEFA can either undergo incomplete oxidation to ketones or be repackaged back into triglycerides. If the capacity for other tissues to use ketones for energy is exceeded, then blood concentrations of ketones rise and negative outcomes from subclinical and clinical ketosis can occur. If triglycerides accumulate in the liver, negative outcomes associated with fatty liver can occur. Triglycerides can be transported out of the liver via very low-density lipoprotein (VLDL) export; however, VLDL export does not keep up with triglyceride concentration during the transition period in dairy cows, largely because of a limiting amount of phosphatidylcholine. (5:51)
Dr. White describes a series of experiments in her lab using liver cells in culture to investigate the relationship between choline supplementation and VLDL export. As choline supplementation to the cell culture increased, so did VLDL export from the cells into the media. In addition, increasing choline supplementation to the cell culture also decreased cellular triglyceride content. (10:54)
Using gene expression and radiolabeled tracers over a series of experiments, Dr. White’s group found that as choline supplementation increased, so did complete oxidation of NEFA to energy. This was accompanied by decreased incomplete oxidation to ketone bodies and decreased accumulation of lipids in the liver cells. Glucose and glycogen were also increased with increasing choline supplementation to the cell culture, and a decrease in reactive oxygen species was observed. In addition, choline-supplemented cultures exhibited an increase in metabolic pathways associated with methionine regeneration and methyl donation. (15:29)
Dr. White then details the complexity of the metabolic pathways that intersect between choline and methionine. In similar experiments supplementing cell cultures with increasing amounts of methionine and choline, there were no effects of methionine on lipid export, oxidative pathways, or glucose metabolism. The main benefit of methionine was a marked increase in glutathione production. It’s important to note that no interactions between choline and methionine were observed in this series of experiments. (19:37)
There seems to be a clear biological priority for different sets of pathways for choline and methionine. Choline seems to be influencing lipid, glucose, and oxidative pathways, while methionine is primarily serving its role as an essential amino acid for cellular protein structure and generation, acting as a methyl donor, and impacting inflammation. Importantly, both the choline and methionine results observed in cell culture are paralleled in transition dairy cow studies. (24:14)
Dr. White’s lab further investigated the impact of methionine on inflammation. When cells were challenged with LPS to provoke an inflammatory response, methionine mitigated the inflammatory response. Similar results have been observed in liver tissue samples of transition cows. Methionine mitigated inflammatory markers and increased glutathione but did not influence reactive oxygen species. Conversely, choline decreased reactive oxygen species but did not change glutathione. (27:47)
Choline and methionine are both essential nutrients, there are biological priorities for them as methyl donors, and they are not mutually exchangeable. The lack of interaction between choline and methionine in vivo or in vitro supports the idea of different biological roles for these nutrients. (32:09)
Dr. White takes questions from the webinar audience. (34:53)
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In part two of a two-part series, the Balchem technical team selected industry research of interest from the 2024 American Dairy Science Association meetings to feature on this episode of the Real Science Exchange.
Smart Cows, Smart Farms: Unleashing the Potential of Artificial Intelligence in the Dairy Sector
Guest: Dr. Jeffrey Bewley, Holstein Association USA (1:58)
Dr. Bewley is the Dairy Analytics and Innovation Scientist at Holstein Association USA, where part of his role is collaborating with Western Kentucky University at the WKU Smart Holstein Lab. The group works with more than 30 technologies, including wearable, camera and machine vision, milk analysis, and automation technologies. At ADSA, Dr. Bewley’s presentation was part of a symposium titled “Applications of AI to Dairy Systems.” His talk focused on cow- and farm-level technologies using artificial intelligence. He anticipates a continued massive increase in the availability of technologies for dairy farms to assist with automating processes that are often monotonous tasks. One example of this is the wearable accelerometer technologies that allow for the assessment of estrous behavior, as well as rumination and eating behavior. In the future, camera-based technologies may become more commonplace for things like body condition scoring. Cameras may also be able to monitor rumination and eating behavior, and even perhaps dry matter intake. Dr. Bewley also sees an opportunity on the milk analysis side to be able to measure even more biomarkers to better manage for improved health, reproduction, and well-being. He reminds listeners that animal husbandry will continue to be a critical piece of dairy farming even with advancing technology. He gives examples of current and cutting-edge technologies on the horizon for dairy farms. On his wish list of technologies for the future, he includes dry matter intake measurement and inline measurement of somatic cell count, hormones, and metabolites in the milk. In closing, Dr. Bewley encourages listeners to be excited yet cautious about artificial intelligence and gives examples of how technology can collect phenotypic data to use in genetic evaluation.
Explaining the Five Domains and Using Behavioral Measures in Commercial Systems
Guest: Dr. Temple Grandin, Colorado State University (26:48)
Dr. Grandin’s presentation was also part of a symposium, titled “The Animal Behavior and Wealthbeing Symposia: Evaluating Animal Comfort and Wellbeing Using the Five Domains.” The five domains approach is gaining popularity. Previous guidance documents emphasized preventing suffering, cruelty, and discomfort. The five domains are nutrition, environment, health, behavior interactions, and the emotional state of the animal. Much of the information available is very theoretical. Dr. Grandin’s goal for this presentation was to gather easy-to-download scoring tools to assist in auditing the five domains in the field. She emphasizes the importance of good stockmanship for animal well-being and cautions that while artificial intelligence technologies can be used to assess the five domains, good stockmanship will always be necessary. Dr. Grandin recommends a three-legged audit: internal, independent third-party, and corporate representatives. She cautions against farming all audits out to a third party and anticipates that it has the potential to cause major supply chain disruptions. Lastly, Dr. Grandin recommends simple yet effective outcome measures for audits that can be taught in a short training session that includes practice audits.
View her five domains paper here: https://pubmed.ncbi.nlm.nih.gov/36290216/
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Nutritionists are often blamed for transition cow problems like high NEFAs, clinical and subclinical ketosis, and subclinical hypocalcemia. Dr. Baumgard suggests these symptoms are a result of one of two situations: 1. These are highly productive, healthy, and profitable cows; or 2. The symptoms are the metabolic reflection of immune activation, likely stemming from metritis, mastitis, pneumonia, or GI tract inflammation. In the first scenario, the nutritionist deserves a raise; in the second, these are mostly management issues not caused by nutrition. (1:26)
If listeners are interested in more detail on this topic, Dr. Baumgard suggests reading this 2021 review in the Journal of Dairy Science: “ Invited review: The influence of immune activation on transition cow health and performance—A critical evaluation of traditional dogmas.”
Link: https://www.sciencedirect.com/science/article/pii/S0022030221006329
Dr. Baumgard highlights key concepts that underpin his thinking regarding transition cows: The best indicators of health are feed intake and milk yield, it’s too easy to overthink the immune system, Mother Nature is rarely wrong, and inconsistent or non-reproducible data should create doubt. He goes on to review the incidence of metabolic disorders in early lactation and the energy balance dynamics of the transition period. (4:29)
For decades, we’ve had the assumption that NEFAs and ketones are causing many of the health issues in transition cows. NEFAs, BHBs, and calcium have been correlated and associated with negative outcomes. However many other studies do not find these negative correlations or associations. Plasma NEFA is markedly increased following calving in almost all cows, yet only 15-20% get clinical ketosis. Dr. Baumgard suggests that it’s presumptuous and reductionist of us to assume we can use one metabolite to diagnose the disease. Little mechanistic evidence exists to explain how these symptoms cause metabolic disease issues. (10:29)
If hyperketonemia, high NEFA, and subclinical hypocalcemia are causing disease, then therapeutically treating these disorders would improve overall cow health. NAHMS data does not back that up. Dr. Baumgard dissects the dogma of ketosis. In short, mobilization of adipose tissues and partial conversion of NEFA to ketones is essential for maximum milk yield. (18:35)
High-producing cows are more hypoinsulinemic compared to low-producing cows, and transition period insulin concentrations are inversely related to whole lactation performance. Low insulin concentrations coupled with insulin resistance allow for fat mobilization. (29:02)
Post-calving inflammation occurs in all cows. Sources include the mammary gland, the uterus, and the gut. Severe inflammation precedes the clinical presentation of the disease. In one experiment, all cows exhibited some inflammation in very early lactation. However, cows that were culled or died before 100 days in milk were already severely inflamed during the first few days of lactation. Dr. Baumgard thinks inflammation is the simplest and most logical explanation for why some cows don't eat well before and after calving. (31:13)
While clinical hypocalcemia (milk fever) is pathological and requires immediate intervention, is subclinical hypocalcemia detrimental to health, productivity, and profitability? (36:33)
Dr. Baumgard’s paradigm-shifting concept suggests that increased NEFA and hyperketonemia are caused by immune activation-induced hypophagia, and hypocalcemia is a consequence of immune activation. He goes on to use a high-producing, a low-producing, and a sick cow to illustrate this concept. (43:26)
In summary, the metabolic adjustments in minerals and energy during the transition period are not dysfunctional and don’t need to be “fixed.” The real fix is to prevent immune activation in the first place to prevent the cow from going off feed. Profitable production is a consequence of wellness. (52:19)
Dr. Baumgard takes a series of engaging questions from the webinar audience. Watch the full webinar at balchem.com/realscience. (56:04)
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The Balchem technical team selected abstracts of interest from the 2024 American Dairy Science Association meetings to feature on this episode of the Real Science Exchange.
Whole Cottonseed and Fatty Acid Supplementation Affect Production Responses During the Immediate Postpartum in Multiparous Dairy Cows
Guests: Jair Parales-Giron and Dr. Adam Lock, Michigan State University (0:58)
The experiment had four treatment groups: no fat supplement, 10% of the diet from whole cottonseed, a 60:30 mix of calcium salts of palmitic and oleic acid at 1.5% of the diet dry matter, and a combination of both whole cottonseed and fatty acid supplement. Energy-corrected milk was increased by almost six kilograms in cows fed the whole cottonseed diet, with a similar increase of more than five kilograms in the fatty acid-supplemented cows during the first 24 days of lactation. However, no further improvement was observed when both whole cottonseed and fatty acids were fed together. The increase in milk production was not accompanied by increased weight loss or loss of body condition.
Effect of Close-Up Metabolizable Protein Supply on Colostrum Yield, Composition, and Immunoglobulin G Concentration
Guests: Dr. Trent Westhoff and Dr. Sabine Mann, Cornell University (17:06)
In this study, cows were assigned to one of two diets 28 days before expected calving: one that provided 39 grams of metabolizable protein (MP) per pound of dry matter and one that supplied 51 grams of MP per pound of dry matter. This represents about 100% of the MP requirement and 140% of the MP requirement, respectively. Diets were formulated to supply equal amounts of methionine and lysine. Cows entering their second parity who were fed the elevated MP diet produced two liters more colostrum than second parity cows fed the control MP diet. This effect was not observed in cows entering their third or higher parity. Overall, higher MP supply did not impact colostrum quantity or quality. Dr. Westhoff also highlights an invited review he authored regarding nutritional and management factors that influence colostrum production and composition. The MP research has also been published; links to both are below.
MP paper: https://www.sciencedirect.com/science/article/pii/S0022030224010774
Invited review: https://www.sciencedirect.com/science/article/pii/S0022030224000341
Colostrum—More than Immunoglobulin G (IgG): Colostrum Components and Effects on the Calf
Guest: Dr. Sabine Mann, Cornell University (41:23)
Dr. Mann presented this abstract at an ADSA symposium titled “Colostrum: The Role It Plays In Calf Health, Development, and Future Productivity.” Her focus was to give credit to the importance of IgG while reminding the symposium audience of the importance of other colostrum components like bioactive factors and nutrients. There is potential that measuring IgG could be a marker for all the other colostrum components that have been transferred as well. We have excellent and cost-effective ways to measure IgG calf-side, but very few bioactive factors can be measured as easily. Heat treatment of colostrum to control bacterial contamination has a detrimental effect on many of the non-IgG components of colostrum. More data is needed to learn how impactful this may be to the calf. Dr. Mann details parts of the heat treatment process that farmers can check to make sure heat treatment is having as little impact as possible. She also would like to have a way to measure the antimicrobial activity of colostrum and the concentrations of insulin and IGF-1 in colostrum on-farm. Lastly, she reminds the audience that we can focus a lot on making the best quality colostrum via transition cow management and best management practices for colostrum harvest, but we still need to get it into the calf. Colostrum must get into calves cleanly and safely, at an adequate amount, and at an optimal temperature.
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This Real Science Exchange podcast episode was recorded during a webinar from Balchem’s Real Science Lecture Series.
Shakespeare wrote, “The eyes are the windows of the soul.” Dr. Ollivett believes the lungs are the window to calf health management. The lungs are an indicator organ: respiratory disease is a symptom of management failure. Failure of passive transfer, diarrhea, septicemia, poor nutrition, a dirty environment, and heat or cold stress can all negatively impact the lungs. Often, this can manifest as subclinical pneumonia, where the lungs are abnormal but the calf externally appears completely normal. (3:51)
Dr. Ollivett reviews the defense mechanisms of the airway. When a veterinarian takes swabs to assess a respiratory disease problem, the bacteria and viruses that live in the nasopharyngeal area just ahead of the trachea are the most representative of those bacteria and viruses that are present in the lungs. The bacteria and viruses in the lower nasal passages are unreliable indicators of what is present in the lungs. (6:28)
Is coughing a good predictor of pneumonia? Research shows that if calves are coughing, it is highly likely they will test positive for a respiratory pathogen. One study showed that coughing was the best predictor of observing pneumonia on lung ultrasound, but only 37% of calves with pneumonia on ultrasound also had a cough. Dr. Ollivett observed similar results in commercial settings, where only about 10% of calves with pneumonia on ultrasound had an accompanying cough. This suggests that a cough is not a good early warning tool for pneumonia. (10:29)
Dr. Ollivett believes respiratory disease exhibits an iceberg effect, where considerably more subclinical respiratory disease exists than clinical respiratory disease. She provides examples of necropsied lungs from dairy calves to emphasize the point that calves can appear completely normal, but have the same or more damage to their lungs compared to calves exhibiting clinical signs of pneumonia. In her work, Dr. Ollivett has found that the sensitivity of lung ultrasounds to find lung lesions in animals with subclinical disease is 88%. (16:32)
What does it take to perform a lung ultrasound? Dr. Ollivett gives an overview of the process and describes what normal and affected lungs look like. Depending on the farm, 50-80% of cases can be subclinical for one to two weeks before we see signs of pneumonia. With lung ultrasounds, you can treat affected animals sooner while also getting a good assessment of where management can improve to better prevent pneumonia cases in the future. (27:37)
The prevalence of the disease is roughly equal to the incidence of the disease times the duration of the disease. Prevention of disease reduces the speed at which disease occurs, thus decreasing the incidence of disease and lowering its prevalence. On the other hand, identifying sick calves sooner should reduce the duration of the disease, also lowering its prevalence. In addition, effective treatment that reduces the duration of disease supports antimicrobial stewardship. Dr. Ollivett details criteria to evaluate treatment failure in your operation, as well as discusses antibiotic therapy in conjunction with lung ultrasounds. (34:29)
Dr. Ollivett emphasizes the impact that the gut has on the lungs on most dairy farms. She feels that as an industry, we are far too comfortable with abnormal manure in 7- to 14-day-old calves. After any abnormal manure, calves are more likely to have abnormal lungs in the next couple of weeks. Ensuring good passive transfer and maintaining a clean environment will reduce lung lesions. (50:50)
To keep calves breathing easy, Dr. Ollivett shares recommendations to reduce management failures before, at, and after birth. These can include clean and adequate space in maternity, clean calf bedding and equipment, the excellent establishment of passive transfer, adequate average daily gains in early life, and routine lung ultrasounds. (53:21)
Dr. Ollivett answers questions from the webinar audience about evaluating treatment protocols for effectiveness, technicalities and landmarks of performing lung ultrasounds, how soon after birth to begin lung ultrasounds, using lung score to determine when to treat with antibiotics, and if lung ultrasounds could be used to cull animals with lung damage before they enter the milking herd. Watch the full webinar at balchem.com/realscience. (55:44)
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Dr. Nydam and Dr. LeBlanc recently presented a Real Science Lecture series webinar on August 7, 2024. You can find the link at balchem.com/realscience.
Dr. Nydam begins with a brief overview of the concepts from the webinar, all based on understanding and applying information from different types of studies on dairy cow health and performance. Dr. LeBlanc adds that their goal was for the webinar to be useful for people with a practical interest in feeding and managing dairy cows. (4:12)
Dr. Nydam discusses different kinds of bias in research. All studies have some bias in them to some extent, so acknowledging, understanding, and trying to control for that is critical. Dr. LeBlanc describes survivor bias. In the simplest sense, survivor bias can be thought of as who’s alive to be counted. Several examples of treatments causing animals to be removed from a study or a disease-causing animal to be culled are reviewed. (8:24)
Both guests give their perspectives on p-values. A p-value tells us the likelihood that a difference we observe is due to chance. There is active discussion among statisticians about the value of the p-value. Both guests suggest that readers should also assess if the study achieved its stated objective and if there are adequate numbers and statistical power to accomplish the objective. P-values help us understand risk. A p-value does not tell us how big a difference was or how important it was. (18:54)
Dr. Nydam reviews that there are two kinds of study validity: internal and external. Internal validity centers around whether the study was done well. Was bias controlled for and acknowledged? External validity centers around the applicability of the study to the population. Is a study about mastitis treatment in water buffalo in Pakistan applicable to a dairy farm on Prince Edward Island? Peer review usually takes care of assessing internal validity. External validity is more up to each reader to decide for themself and their situation. (29:01)
Scott asks about the validity of field trial data. Both guests acknowledge the inherent challenges of field studies and give some tips for success. Field studies can often have good external validity because they are done under real-world conditions and at scale. (34:23)
The group dives into the topic of industry-funded research. Some skepticism and cynicism about industry-funded research exists. Industry-funded studies are not inherently biased and often answer important and tangible questions for decision-makers. Government funding is rarely going to be awarded to that type of research, but the industry is interested in funding it. If an industry-funded study is well done by a reputable researcher, has gone through the peer review process, and has appropriate methods and statistics, Dr. Nydam sees no reason to discount it. (44:56)
Dr. LeBlanc reminds the audience when looking at different kinds of studies and different types of evidence, it’s not that one type of study is good and others are not. For a lot of health-related research in dairy cows, we don’t have good (or any) experimental models to reproduce things in a white-coat-science sort of way. At the end of the day, dairy managers and industry professionals want to know if a particular piece of science, whether experimental or observational, helps them make decisions on the farm. There’s a place for all types of research as long as it’s done well and in its own right. (42:08)
Dr. Nydam’s key takeaway is that it’s important to remember to keep some faith in science and have open discourse about it as we move forward in dairy science and as a society. Dr. LeBlanc reminds the audience that even if listeners are not in the business of designing, conducting, and analyzing their experiments, they do not need to feel powerless as consumers of scientific information. It can and should be something they can engage with and use to answer questions in their day-to-day jobs. (52:26)
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This Real Science Exchange podcast episode was recorded during a webinar from Balchem’s Real Science Lecture Series.
The primary goal of a replacement program is to raise the highest quality heifer that can maximize profits when she enters the lactating herd. She carries no limitations that would detract from her ability to produce milk under the farm’s management system. Ideally, one would wish to optimize profits by obtaining the highest quality heifer at the lowest possible cost, usually in the least amount of time. Dr. Van Amburgh presents a snapshot evaluation of benchmarks to assess the potential quality of replacements. (3:47)
When does the process of creating a quality heifer start? Probably before conception. In non-pasture herds, the first lactation cows giving birth to heifers produced about 1000 pounds more milk in the first two lactations. Heifers whose dams were supplemented with choline during the pre-fresh period had higher birth-to-yearling average daily gains and improved immunity. Choline also appears to enhance the quality of colostrum via increased absorption of IgG. This implies that maternal programming extends beyond the uterine environment via ingestion of milk-borne factors, known as the lactocrine hypothesis (14:29)
After the calf is born, the goal is anabolism or growth. The dam communicates with the calf via colostrum to direct calf development after birth. Not only does colostrum provide immunoglobulins, but it also contains a large amount of nutrients and non-nutrient factors that support gut maturation. In particular, IGF-1 and insulin may act on receptors in the gut to stimulate cell proliferation, cell differentiation, and protein synthesis. Dr. Van Amburgh summarizes several studies that showed increased colostrum feeding improved pre- and post-weaning growth and development. While the immunoglobulin content of colostrum is essential for passive immunity, the other components in colostrum are responsible for the increased growth performance. (27:39)
The hormones and growth factors in colostrum enhance protein synthesis, enzyme expression, and gastrointestinal tract development. This implies that the gut is now an even stronger barrier to infection, with more surface area for digestion and absorption, with an increased capacity to digest nutrients due to higher enzyme excretion. (36:33)
To investigate the impact of non-nutrient factors in colostrum, studies were designed where calves were fed either colostrum or milk replacer with the same nutrient content. Glucose uptake was increased for colostrum calves even though both groups received similar nutrient content. Plasma glucagon was higher in colostrum calves, indicating better glucose status and higher reserve capacity. Plasma protein levels were higher in colostrum calves, suggesting more amino acids available for growth and protein synthesis. Plasma urea nitrogen was lower for colostrum calves, indicating fewer amino acids were used for gluconeogenesis leading to more efficient growth. (46:55)
What happens to immune cells in colostrum? Leukocytes and other immune-related cells in colostrum are trafficked into the circulation of the calf. Maternal leukocytes can be detected in the calf by 12 hours, peak at 24 hours, and disappear by 48 hours. Long term, there appears to be greater cellular immunity in calves that received whole colostrum compared to cell-free colostrum. Uptake of cells from colostrum enhances cellular immunity in calves by providing, mature, programmed cells from the dam. (52:24)
The take-home message for colostrum management is to feed colostrum for four days. Give first-milking colostrum within six hours of birth and again at 12 hours. Give second-milking colostrum for day two feeding and third- and fourth-milking colostrum for days three and four. (56:04)
Dr. Van Amburgh answers a few questions from the webinar audience about dry cow management for colostrum quality and quantity, the impacts of pasteurization of colostrum on components, and the efficacy of colostrum replacers. Watch the full webinar at balchem.com/realscience. (58:25)
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Dr. Mitloehner recently presented a Real Science Lecture series webinar on September 11, 2024. You can find the link at balchem.com/realscience.
Dr. Mitloehner begins by sharing about the Clarity and Leadership for Environmental Awareness and Research (CLEAR) Center at UC Davis. He established this research and communications center to combat misinformation about sustainability in animal agriculture. One unique aspect of the center is a diverse communications department composed of journalists, filmmakers, and social media experts to help scientists communicate with the public. (6:04)
In his webinar, Dr. Mitloehner focused on animal agriculture’s impact on the climate, particularly via methane. Unlike other greenhouse gasses, methane is not only naturally produced, but it is naturally destroyed. It remains in the atmosphere for about a decade before it’s gone. Thus, if mitigation methods are used to reduce methane production, warming will also be reduced. (8:10)
Dr. Mitloehner urges continued research into improving efficiency in food production and encourages animal agriculture to take the public along with them. Stop portraying a romanticized, Old McDonald's version of animal agriculture and show what happens. There is nothing to be ashamed of, and we should be proud of the improved efficiencies and sustainability of livestock production. (13:00)
What methods or strategies exist for reducing methane? Improved ration development and feed additives to reduce enteric methane are two examples. Methane production is a heritable trait, and genomic tests are available to identify low and high methane producers. There are also ways to reduce methane loss from animal manure, including capping lagoons with anaerobic digesters to capture the gas and turn it into fuel. Dr. Mitloeher encourages voluntary, incentive-based adoption policies for these practices. (16:03)
Dr. Nichols describes her work in the Netherlands on reducing nitrogen losses. Improving protein efficiencies in livestock in the Netherlands is motivated first by environmental concerns and then by cost. Dr. Nichols expects increasing pressure in the United States regarding nitrogen load, particularly in intensively farmed portions of the country. At UC Davis, she plans to continue researching protein efficiency in dairy cows with a particular interest in optimal digestible amino acid profiles for efficient milk production. (24:00)
Reducing crude protein in the diet decreases the amount of nitrogen excreted. As protein concentrations become more marginal, that’s when the composition of protein and amino acid in the diet becomes more critical. Dr. Nichols has found in infusion studies that the closer the digestible amino acid profile is to the essential amino acids in casein, the more efficiently dietary protein is incorporated into milk protein. (32:20)
Dr. Mitloehner gives some examples of some of the incentives available to farms in California, as well as what he sees for the future in this regard. Many of the incentives are based on improvement, which discourages early adoption and Dr. Mitloehner feels this is nonsensical. Dr. Nichols chimes in with some of the incentive-type structures in Europe. (36:21)
An additional challenge in the greenhouse gas arena is that there is no standardized protocol or measurement technique to quantify emissions. There is some effort from the United Nations and FAO to standardize some of these measures. Panelists agree that farmers are well served to document what they do and record benchmarks for things where measurements are standardized. (44:49)
Conor’s big takeaway from this discussion is that research is ongoing to create a low emission sustainable future for animal agriculture that will take collaboration between science and policy to implement widely. Dr. Nichols reminds the audience that nitrogen should absolutely be on the minds of farmers and nutritionists, not only from an economic perspective of your ration, but also because of its environmental impact. Nitrogen mitigation is far more complicated than methane mitigation. She encourages listeners to take a look at the composition of the protein in their rations, keep good records, and see what kind of marginal changes you can make. Dr. Mitloehner encourages the audience to remember that environmental issues are intertwined with animal health and the profitability of an operation. We should not ignore emissions, we should become part of a solution. Lastly, we must find ways to effectively communicate about animal agriculture to the public. (55:31)
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Dr. Arshad begins by reviewing the inclusion criteria in the meta-analysis he conducted. He wished only to look at studies where lysine was supplemented in a rumen-protected form. The meta-analysis did not include studies that infused lysine into the abomasum or intestine. In addition, only completely randomized design or randomized complete block design studies were included. Feed ingredients and chemical composition of diets for each experiment were run through NASEM to predict the metabolizable lysine content using the same model so all studies were on the same scale. (6:04)
The bioavailability of the different rumen-protected lysine products used in the studies ranged from 22 to 90 percent. If the paper's authors reported bioavailability values, they were used in the meta-analysis. If the paper did not provide bioavailability values, Dr. Arshad contacted authors or lysine product manufacturers to offer them. (13:53)
Dr. Arshad discusses the percentage of lysine as a percent of metabolizable protein in the diets as well as differences among the prediction of the flow of amino acids to the small intestine from NASEM, NRC, and CNCPS models. (16:45)
Around 40% of the meta-analysis dataset was from early lactation cows where rumen-protected lysine was supplemented starting from 20 days in milk. The rest of the dataset came from mid-lactation cows. The duration of lysine supplementation also varied. Cows supplemented with rumen-protected lysine for more than 70 days In early lactation produced 1.5 kilograms more milk than control cows. Mid-lactation cows supplemented for less than 70 days produced 0.8 kilograms more milk than control cows. Increasing lysine as a percentage of metabolizable protein linearly increased milk and component yield. (20:11)
During the transition period, cows not only experience negative energy balance but also negative protein balance, estimated at one kilogram of protein loss from skeletal muscle during that time. Plasma lysine starts to decrease around 21 days before calving but bounces back after seven days in milk. This suggests that lysine utilization by the mammary gland and other tissues is high during the prepartum period. Supplementing lysine before calving and during early lactation should improve the efficiency of protein synthesis and may explain the difference between early and mid-lactation responses observed in the meta-analysis. (24:10)
Lysine supplementation improved feed efficiency. Dr. Arshad discusses potential reasons for this and also points out that somatic cell counts were lower for lysine-supplemented cows, suggesting that this amino acid may be important for mammary gland health. He also discusses some of the interactions with methionine found in the meta-analysis. Dr. Zimmerman and Dr. Arshad also hypothesize about the mechanism of action of supplemental lysine increasing milk fat percentage. (30:44)
Dr. Arshad describes how he would design the next rumen-protected lysine study given what he learned from the different studies in the meta-analysis. In particular, he would like to see more work with primiparous cows, and dose-titration studies to pinpoint the optimal amount of lysine to supplement and to further explore the impact of lysine on immune function. (42:42)
The base diet and bioavailability of the rumen-protected lysine product are critical components to determine the supplementation rate for a particular group of cows. Dr. Arshad details the differences between this meta-analysis and previous meta-analyses regarding lysine supplementation. (46:40)
In closing, Dr. Zimmerman was excited to see this meta-analysis and it validated observations from the field. Dr. Weiss underlines the strict inclusion criteria and regression analysis as particularly strong points in the paper. Finally, Dr. Arshad reminds the audience that creating a balanced ration should include essential and non-essential amino acids. He again emphasizes the importance of having an understanding of the bioavailability of rumen-protected products before conducting research projects with them. Lastly, he identifies a research gap regarding lysine supplementation of primiparous cows, which make up 30-35% of herd dynamics. (52:43)
You can find this episode’s journal club paper from the Journal of Dairy Science here: https://www.journalofdairyscience.org/article/S0022-0302(24)00499-5/fulltext
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This episode of the Real Science Exchange podcast was recorded during a webinar from Balchem’s Real Science Lecture Series.
Choline was discovered in 1862 in pig and ox bile (“chole” in Greek). It is a simple nutrient containing five carbons and a nitrogen. Choline is considered a quasi-vitamin since its requirements and de novo synthesis are both higher than the B vitamins it’s similar to. Pigs can synthesize more choline than chickens. Choline is considered to be a conditionally essential nutrient depending on the physiological stage and choline production ability of the species being considered. (3:29)
Choline is involved in cellular maintenance and growth at all life stages. In particular, it’s involved in neurotransmission as a component of both sphingomyelin and acetylcholine. Phosphatidylcholine is a major component of cellular and organelle membranes and is involved in lipoprotein synthesis for the transport of lipids. Choline is converted to betaine upon oxidation, and betaine plays an important role in one-carbon metabolism as a methyl group donor. (8:43)
Dietary-free choline is preferentially used for acetylcholine and phosphatidylcholine synthesis. Phosphatidylcholine is the most abundant form of choline in the body. In general, water-soluble forms of choline are absorbed faster and have a higher tissue incorporation rate than lipid-soluble forms. (14:58)
Clinical signs of choline deficiency include reduced growth and reproductive performance. In pigs and chickens, choline-deficient diets lead to lipid accumulation in the liver. In broiler chickens, perosis is a classic choline deficiency sign and may progress to slipped tendons. From human studies, we know that insufficient methylation capacity during early development increases the risk of neural tube defects and impaired cognitive function. (16:44)
As animals age, their dietary source of choline transitions from water-soluble forms to lipid-soluble forms. Mammalian young receive water-soluble choline from milk, and avian species from the egg yolk. After weaning in pigs and at the hatch in chickens, the dietary choline source transitions to lipid-soluble forms found in oilseed meals. Dr. Dilger goes on to describe choline concentrations in common feedstuffs and supplements. Feedstuff type and processing methods have a profound influence on bioavailable choline content. (19:16)
Dr. Dilger details some of his work with choline and betaine in poultry diets. The requirement for preformed choline is relatively high for poultry because they lack capacity in a particular methyl transferase enzyme responsible for de novo synthesis. They also have relatively high choline oxidase activity which favors the formation of betaine from choline. Betaine is critical as a buffer to counteract the toxic effects of uric acid in the avian kidney. Dr. Dilger describes choline dietary requirements for avian species. (27:38)
Pigs have more efficient methyl transferase activity for de novo synthesis of choline. Sufficient choline is provided by milk and practical diets. For growing pigs consuming corn-soybean meal diets where methionine can completely spare choline, there is little benefit of choline supplementation for growth. Choline requirements increase for gestating and lactating sows. Swine requirements for choline were set in the 1940s and 1950s. Dr. Dilger believes these requirements need a second look given the great changes in pig and crop genetics since the requirements were originally established. To that end, work in his lab has shown that choline intake during gestation and lactation influences sow milk composition, body choline concentrations and forms, metabolomic profiles and brain development of pigs. (35:18)
In conclusion, Dr. Dilger considers choline a pervasive nutrient due to its crucial metabolic roles. Species-specific idiosyncrasies drive choline requirements, and analytical data for choline-related compounds is lacking. Different forms of choline have different metabolic kinetics and the potential for choline deficiency remains a practical issue. (46:15)
In closing, Dr. Dilger answers an extensive set of questions from the audience. Watch the full webinar at balchem.com/realscience. (48:32)
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Dr. Kononoff’s lab evaluated retrospective feed mixing records collected from eight commercial dairy farms. Data was divided into 28-day periods. Daily TMR nutrient deviation was automatically calculated from feed mixer data as the actual amount of a nutrient fed minus the target amount from the original diet formulation, divided by the target amount. (5:43)
Crude protein, NDF, fat, and starch were the nutrients evaluated in the study. (13:40)
Variation was positive for every nutrient on the vast majority of days. Dr. Kononoff attributes that to more feed being delivered than the diet formulation predicted animals would consume. Dry matter intake decreased with increasing positive deviation days in starch and increased with increasing positive deviation days in crude protein. NDF deviation did not impact dry matter intake. A narrow range of diets was used in the dataset and the main byproduct feed was high in NDF, so Dr. Kononoff speculates that there was not a wide enough range in NDF to have an impact on intakes. (17:04)
Milk yield increased with increased positive deviation days in starch and decreased with increased positive deviation days in NDF. The pregnancy rate increased with increasing positive deviation days in fat and decreased with increasing positive deviation days in crude protein. Unfortunately, milk urea nitrogen data was not available in the dataset to further investigate the crude protein/pregnancy rate relationship. (20:44)
There was little farm-to-farm variation in the data. (25:08)
As positive deviation days for starch increased, so did feed conversion. The opposite effect was noted for NDF. As positive deviation days for fat increased, feed conversion decreased. This result was a little surprising, as delivering more energy usually improves feed conversion. However, the dataset did not specify the source of fat or fatty acid profile, so there may have been some rumen fermentation interference from fat. (27:08)
Dr. Kononoff thinks it would be interesting to track individual cows through lactation and collect nutrient variation data. Dr. Weiss asks if the correlation between daily farm milk yield and nutrient variation was evaluated; it was not. Dr. Kononoff agrees that there may be some additional correlations that would be interesting to run. (33:22)
In closing, Dr. Zimmerman commends Dr. Kononoff’s work in tackling such a large dataset and looks forward to follow-up research. Dr. Weiss agrees and encourages more data extraction from the dataset. He was also very surprised at the low farm-to-farm variation observed and speculated if that would hold up if there were more variation in diets. Dr. Kononoff reminds the audience that taking a look at the TMR beyond the paper ration and digging into mixing techniques and TMR consistency is as important as evaluating bulk tank information or the amount of milk shipped. (37:20)
You can find this episode’s journal club paper from the Journal of Dairy Science Communications here: https://www.sciencedirect.com/science/article/pii/S2666910224000760
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Balchem sponsored several abstracts presented at the 2024 ADSA Annual Meeting. This episode consists of five segments, each focused on an abstract.
Segment 1: Evaluating the total mixed ration stability of rumen-protected lysine products.
Guests: Kari Estes, Balchem; Dr. Mark Hanigan, Virginia Tech
This research compared the TMR stability of a Balchem prototype, several commercially available rumen-protected lysine products and a positive control of unprotected lysine. (3:39)
A sample of TMR and the equivalent of one gram of lysine from each product were mixed and placed in a plastic zip bag for 0, 6, 12, or 24 hours. After each time point, the sample was placed in a strainer bag, dipped in distilled water, and drip-dried. The solution was collected and analyzed for free lysine content. (5:28)
About 85% of the unprotected lysine was recovered at 0 hours. After 24 hours, around 50% was recovered. The rumen-protected lysine products varied widely; one product released nearly 87% of its lysine in 24 hours, while another only released 9%. TMR stability should be taken into account when determining feeding rates and handling of rumen-protected lysine products. (7:19)
Segment 2: Evaluating the total mixed ration stability of rumen-protected choline products.
Guests: Kari Estes, Balchem; Dr. Mark Hanigan, Virginia Tech
In this experiment, Kari evaluated TMR stability of five commercially available rumen-protected choline products, along with a positive control treatment of unprotected choline chloride. (14:04)
At 0 hours, about 80% of the unprotected choline was recovered and 50% was recovered at 24 hours. Results for the rumen-protected choline products were highly variable, ranging from 5% release to 100% release at 24 hours. Rumen-protected choline products should be evaluated for TMR stability in addition to rumen stability and intestinal release. (17:25)
Segment 3: Effect of dry period heat stress and rumen-protected choline on productivity of Holstein cows.
Guests: Maria Torres de Barri and Dr. Geoff Dahl, University of Florida
The experiment had four treatments: heat stress with and without rumen-protected choline, and cooling with and without rumen-protected choline. Cows in the cooling treatment were provided shade, soakers, and fans, while cows in the heat stress treatment were only provided shade. (24:45)
Heat-stress cows had higher rectal temperatures and respiration rates than cooled cows. Heat-stress cows also had lower dry matter intakes, shorter gestation length, lighter calves, and produced less milk. (29:36)
For cows in the cooling group, choline supplementation increased milk production. However, cows in the heat stress group supplemented with choline produced less milk than cows who did not receive choline. (31:04)
Dr. Dahl suggests that not cooling cows in heat-stress environments when they’re receiving choline will not result in optimal results. (33:49)
Segment 4: Effects of dietary rumen-protected, ruminal-infused, or abomasal-infused choline chloride on milk, urine, and fecal choline and choline metabolite yields in lactating cows.
Guests: Mingyang (Charlie) You and Dr. Joe McFadden, Cornell University
This experiment evaluated early and late lactation cows supplemented with choline via three different methods. Each treatment had 12.5 grams of choline ion provided daily: fed in rumen-protected form, continuously infused into the rumen, or continuously infused into the abomasum. (36:29)
Choline bioavailability was influenced by the delivery method of choline. Fecal and milk choline concentration was only observed in early lactating cows with abomasal infusion. Abomasal infusion increases the choline metabolite betaine in feces and urine. These results suggest there is potential saturation of choline metabolism in the lactating cow. (40:53)
Segment 5: The metabolic fate of deuterium-labeled choline in gestating and lactating Holstein dairy cows.
Guests: Dr. Tanya France, University of Wisconsin; Dr. Joe McFadden, Cornell University
Dr. France explains that choline can be metabolized via two different pathways. Using deuterium-labeled choline (D-9 choline) allows researchers to know which pathway is used. If D-3 or D-6 choline is measured, the methionine cycle is used, and if D-9 choline is measured, the CDP choline pathway is used. The hypothesis was that the physiological stage (late gestation vs early lactation) would influence choline metabolism. (51:06)
Dr. France found that both choline metabolism pathways were used in both physiological stages. This experiment also confirmed that choline is a methyl donor and that choline recycling can occur. The research also evaluated the relative amounts of choline and choline metabolites in each pool. (53:40)
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This episode of the Real Science Exchange podcast was recorded during a webinar from Balchem’s Real Science Lecture Series.
Throughout the last 30 years, the dairy industry has moved to producing highly concentrated versions of milk proteins. In cows’ milk, about 80% of the protein is casein and 20% is in the serum or whey phase. These ratios vary by species. There are three major caseins in cows’ milk: alpha-S-casein, beta-casein, and kappa-casein. The first two are rich in phosphate for calcium binding. Kappa-casein is critical in a micellar structure that allows these structures to stay suspended in the milk. (1:21)
Whey proteins also differ by species. In cows’ milk, about 50% of the whey protein is beta-lactoglobulin. It’s rich in branched-chain amino acids, and it is not present in human milk so it is a focus of allergy research. Alpha-lactalbumin is found in all mammals and is a cofactor for lactose production. (10:34)
Caseins and whey proteins are different from one another and are in completely different classes of proteins. From structure, to size, to amino acid content, to solubility; these two types of proteins are yin and yang. (11:51)
When fluid milk or whey is concentrated by removing water, some sugars and other materials dissolve via evaporation or membrane filtration. It results in dried powders, milk protein concentrate, milk protein isolate, whey protein concentrate and whey protein isolates. Concentrates contain 80-85% protein and isolates contain more than 90% protein. (17:14)
What's driving the current and probably future popularity of these dairy proteins? One, is their versatility in many food applications, and the other is the superior nutritional quality of the proteins. Nearly half of the milk protein concentrate use is for mainstream nutrition and sports beverages. Similar trends have been observed for whey protein isolates. (20:05)
Dairy proteins are very rich in branched-chain amino acids (BCAA) like leucine. BCAAs help initiate protein synthesis, are important for muscle recovery, help with weight loss by maintaining blood glucose levels, are synergistic with exercise, and can promote healthy aging. Dr. Lucey gives several different examples of products utilizing dairy proteins. He predicts that the increased focus on nutrition products, interest in isolating individual proteins and improving export opportunities will continue to drive demand for dairy proteins in the future. (27:21)
All of the main milk proteins have genetic variants, which are minor amino acid differences in the same protein. Variants occur at different frequencies among breeds. Beta-casein has two variants, A1 and A2. There is one amino acid difference out of 209 total amino acids, located at position 67 where a histidine is found in variant A1 and a proline is found in variant A2. When histidine is present, the beta-casein is prone to cleavage at position 67, creating a fragment called beta-casomorphin-7 (BCM-7). When proline is present, it hinders the cleavage of casein at position 67. BCM-7 is an exogenous opioid peptide with the potential to elicit opioid activity on a range of tissues and organs. It’s known as a “bioactive peptide” and some others from milk and cheese have been implicated as anti-hypertensive. (35:26)
In the late 1990s, some researchers claimed that A1 milk was implicated in diabetes, coronary heart disease, autism, and schizophrenia. Subsequent reviews and investigations by significant international bodies found no evidence of these claims. (40:34)
In closing, Dr. Lucey answers questions from the webinar audience. He talks about the potential of breeding cows customized for the production of minor milk components, milk components as renewable bio-plastics, and the superiority of milk proteins compared to plant proteins. Watch the full webinar at balchem.com/realscience. (47:41)
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Dr. Overton presented on this topic in a Real Science Lecture series webinar on July 10, 2024. You can find it at www.balchem.com/realscience. This episode takes a deeper dive into the conversation.
Dr. Overton begins by reminding listeners of the vast number of changes occurring in the fresh cow during the first two to three weeks after calving. Body fat and protein mobilization, some systemic inflammation, the potential for elevated NEFAs and ketones, and calcium dynamics all play a role in how the fresh cow starts her lactation period. (7:31)
When consulting with clients, Dr. Faldet uses research to guide his decisions. He likes to implement a 14-day pen for fresh cows, ranging from 10-17 days. He evaluates things like stocking rates, lockup times, and cow comfort, along with fine-tuning a diet for each individual farm setting. (9:14)
The panel discusses the importance of increasing effective fiber along with starch in fresh cow diets. Without adequate effective fiber in the diet, the risk of acidosis increases, resulting in cows going off feed. There is no silver bullet; each farm’s fresh cow diet is going to be different due to different forage bases and timing in the fresh cow group. (13:02)
Both Dr. Faldet and Dr. Overton stressed the diet is only one component of a successful fresh cow program. Other critical pieces include stocking rate, availability of feed, water quantity and quality, and cow comfort. Dr. Faldet suggests that if you do all these non-diet factors right, you could probably maneuver closeup and fresh pens a little differently and make the diet work with the ingredients you have. Dr. Overton’s group is conducting survey work evaluating the variability in particle size in closeup diets. A pilot study showed that as particle size variability increased, so did fresh cow health issues and poor postpartum metabolic status. (19:10)
Protein requirements of the fresh cow were another topic of Dr. Overton’s webinar. He described a recent experiment evaluating standard and high metabolizable protein concentrations in the diet for closeup and fresh cows. The postpartum MP gave a big milk response, around 15-16 pounds per day for the first 21 days after calving, with a carryover effect of 11-12 pounds of milk for the next 20 days after all cows went back on the same diet. It’s important to note that lysine and methionine were fixed regardless of treatment, so it seems that other amino acids are probably involved in the mechanism of action. (23:06)
Dr. Overton described an experiment designed to evaluate starch and fiber in fresh cow diets where higher fiber digestibility and increased corn in silage resulted in less fiber and more starch than anticipated in the diet. Fresh cows were a bit of a trainwreck, but the problem was resolved once another couple of pounds of straw were added to the diet. On the other hand, you can go too far with increased fiber in fresh cow diets, which results in ketosis, lower intakes, and less milk production. (35:19)
The panel then discusses far-off programs, fat supplementation in fresh cow diets, and vitamin and mineral concentrations for fresh cows. (42:37)
In summary, each panelist shares their takeaways. Dr. Elliott reminds listeners that we should think about starch, fat, fiber, and protein together and how they influence each other rather than considering them individually. Dr. Faldet’s take-home message is to know what your targets and bookends are and really hone in and implement your fresh cow diets accordingly. Dr. Overton suggests that the industry will shift to evaluating fresh cow diets as their own thing rather than trying to tweak a few things from your high cow diet. Implementing fresh cow diets consistently and well is going to be important. (53:30)
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Dr. Callaway presented on this topic in a Real Science Lecture series webinar on June 4, 2024. You can find it at www.balchem.com/realscience. The following podcast takes a deeper dive into the conversation.
For years, probiotics were known as direct-fed microbials (DFMs) in livestock and probiotics in humans. Terminology has been updated to reflect different modes of action and composition. (9:07)
A probiotic is defined as a living microorganism that will be beneficial to the health and/or performance of the host. Prebiotics are fermentable substrates that the host can’t use, but the microbes can. Dr. Steele agrees that terminology and definitions keep evolving; he uses “microbial-based solutions” rather than DFM. He believes that the ever-evolving terminology and definitions have led to some of the skepticism about these products in the industry. He recommends to farmers and nutritionists that a product should have a bare minimum of three publications in high-quality peer-reviewed journals showing efficacy before using them on-farm. (10:13)
Every farm is going to have a different set of challenges and goals that will play a role in determining the right choice of microbial-based solution. Weather and climate, water quality, pathogen challenges, ration grind size, and ration ingredients will all factor into the decision. (17:39)
Both guests agree that we don't know enough about the microbiome in cattle to define what a good versus a bad microbiome looks like. Dr. Steele suggests the next steps in research should look more deeply at the host’s physiological mechanisms in how they’re responding to a probiotic to truly understand when it’s going to work and when it’s not. (21:19)
Dr. Ordway asks how much microbial products could improve the absorption of nutrients. Dr. Steele responds that much of the research so far has focused on digestion and absorption has not been studied much. Some studies in calves fed microbials have shown changes in gut structure and the development of villi, and even papillae in the rumen. That gives us some high-level information about absorption, but we are not close to understanding the nitty gritty of the microbial mechanisms at play in absorption. Dr. Callaway adds that hindgut absorption in ruminants is more important than we have previously thought. Dr. Steele suggests the small and large intestines are equally as important as the forestomach, but they are not as well understood as they’re harder to study in ruminants. The conversation goes on to discuss possible modes of action behind increased liver abscesses observed in beef on dairy operations. (30:12)
Both guests share their thoughts regarding working together across disciplines, especially agronomy researchers since the feed base has such an impact on-farm. They discuss soil microbes, forge inoculants, and silage microbes. (43:23)
Dr. Ordway’s take-home message for nutritionists is to not forget to have conversations with your partners - the producer, the end user, the veterinarian, the crop team and the management team on the farm. Coordinated biology is not just within the animal, it’s all the factors coming into play that have been discussed in this episode. (58:32)
Dr. Steele reiterates his earlier advice to only use microbial-based solutions that have a bare minimum of three publications showing efficacy in a high-ranking journal. He also recommends you choose your metric of measurement properly. Focusing on cattle that are experiencing some stress or metabolic or infectious issues may allow you to truly evaluate the return on investment. There are great microbial solutions out there but you need to use a proven solution from a company that’s research-based. (59:48)
Dr. Callaway echoes Dr. Steele’s recommendation to be slightly cynical about companies that come in to sell you things. Ask how their product works, and ask to see the research. A company that tells you when its product works and when it doesn’t might be more trustworthy than one that says their product always works. Lastly, what does success look like for you as a farmer? Have a measurable, bite-size metric for determining if these products impact your bottom line. (1:01:28)
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This episode of the Real Science Exchange podcast was recorded during a webinar from Balchem’s Real Science Lecture Series.
Dr. Goff sees three main challenges for transition cows: negative energy and protein balance, immune suppression, and hypocalcemia. About half of all older cows experience hypocalcemia, and around 3% will experience milk fever. Cows develop hypocalcemia if they are unable to replace the calcium lost in milk from either their bone or diet. Compared to the day before calving, a cow needs around 32 extra grams of protein the day of calving to meet her increased requirements. (2:00)
Dr. Goff reviews the pathways of calcium homeostasis and the actions of parathyroid hormone (PTH). Aged cows may have a harder time maintaining calcium homeostasis due to the loss of vitamin D receptors in the intestine with age and fewer sites of active bone resorption capable of responding quickly to PTH once they have finished growing. Blood pH plays a role in calcium homeostasis: when blood pH becomes alkaline, animals become less responsive to PTH. Dr. Goff reviews the impacts of high vs low DCAD diets and reviews the amount of time it takes for the kidney and bone to respond to PTH. (4:20)
There are several strategies to reduce the risk of hypocalcemia. One is to reduce dietary potassium so the cow is not as alkaline. Using forages from fields that have not had manure applied to them is one way to accomplish this. In addition, warm-season grasses (corn) accumulate less potassium than cool-season grasses, and all grasses contain less potassium as they mature (straw). A second strategy is to add anions such as chloride or sulfate to the diet to acidify the blood to improve bone and kidney response to PTH. Research has shown that sulfate salts acidify about 60% as well as chloride salts. The palatability of anionic diets has led to commercial products such as Soychlor. (13:06)
Dr. Goff then discusses the over- and under-acidification of diets and gives his opinion on the appropriate range of urine pH for proper DCAD diet management, including a new proposed DCAD equation to account for alkalizing and acidifying components of the diet. He also gives some options for pH test strips to use for urine pH data collection. (18:30)
Dr. Goff’s lab has found that as prepartum urine pH increases, the calcium nadir decreases. The inflection point is right around pH 7.5, where above 7.5 indicates a higher risk of hypocalcemia. Data from other researchers suggests that urine pH lower than 6.0 may result in lower blood calcium, indicating an overall curvilinear response. Low urine pH (under 6.0) has also been associated with a higher incidence of left-displaced abomasum. (29:02)
Moving on to other minerals, Dr. Goff discusses phosphate homeostasis and how that interacts with calcium in the close-up cow. Feeding too much phosphorus can decrease calcium absorption and feeding low phosphorus diets before calving can improve blood levels of calcium. He recommends less than 0.35% phosphorus in close-up cow diets. For magnesium,he recommends 0.4% prepartum and immediately postpartum to take advantage of passive absorption across the rumen wall. (31:08)
Another strategy to reduce milk fever risk is to reduce dietary calcium prior to calving to stimulate parathyroid hormone release well before calving. A zeolite product that binds calcium is now available and may make this much easier to achieve. (42:59)
In closing, Dr. Goff reminds the audience that some level of hypocalcemia post-calving is normal and in fact, is associated with higher milk production. The key is making sure that the cow’s blood calcium levels can bounce back to normal by day two after calving. (51:23)
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Dr. DeVries presented a Real Science Lecture webinar on May 8, 2024, titled “Lessons Learned in Research on Nutritional Management of Robot Milked Cows.” You can find the webinar recording at balchem.com/realscience.
Dr. DeVries begins with an overview of how his robotic milking research has evolved. In Canada, around 20%-plus of farms are using robotic milkers. He describes survey research in the US and Canada as to why producers choose to implement robotic milkers. (9:19)
In Trevor’s webinar, he discussed the large amount of variation in nutritional management of robot-milked cows across Canada. Some of his research with Dr. Penner has looked at the interaction between feed consumed at the feed bunk and feed consumed at the robot. Ideally, you wish to be able to accurately predict intake because that is a primary driver of milk production. Because cows can be supplemented individually at the robot, there is opportunity to better feed cows to match their individual needs. (13:50)
Trevor and Greg describe their respective university’s robot milking research facilities. The panel discusses additional technologies that would be useful for all robotic milkers, like load cells to measure feed delivery and disappearance. Cows typically consume around 250-300 grams of concentrate per minute, and that can vary by feed type (pellet vs mash, for example.) The panel also ponders whether the design of the feed bunk in the robots has an impact on intake rate. (17:35)
As a consulting nutritionist, Todd prefers to feed as little as possible in the robot and have a more consistent mix in the PMR. The level of milk production of the cows can have a large influence on how much pellet is fed at the robot versus the feed bunk. Todd goes on to describe his strategy for creating proportions of PMR and robot intakes for different scenarios. (26:06)
Clay asks the panel what the maximum amount of concentrate should be fed at the robot. They discuss factors that can influence concentration including individual cow variation, length of time in the robot per milking, and the number of visits to the robot per day. Clay goes on to ask how fast fresh cows can be stepped up in their robot feedings. The group has a lively discussion about all the different factors that play a role in that decision. Greg reminds the audience not to get so caught up with programming the robot that we lose sight of the fact we’re still feeding cows and good dairy management still applies. (31:29)
Todd describes some of the biggest challenges he observes as a consultant in robotic dairies, primarily centered around understanding cow behavior. Trevor underlines the importance of cow comfort and other non-nutritional factors in regard to their influence on the success of the nutrition program.(41:29)
Scott asks the panel what they think robotic milkers might look like in 2050 and what problems will have been solved by then. Greg’s wish list includes knowing PMR intake to better manage robot feedings and having cow body weights on every dairy. Trevor thinks we will have a much better understanding of how genetics influence cow performance in a robotic system and how we can raise cows to adapt to the technology to be better robot cows. Todd agrees that body weights are critical and also envisions more individualized milkings depending on each cow’s preferences. On his wish list is a drone that could be used to fetch cows to the robot who have not gone to be milked. (46:51)
Trevor and Greg discuss what’s next in their upcoming research projects, and Todd gives some wishlist ideas for future research. (54:18)
In summary, each guest gives their take home messages. Clay is intrigued by the precision feeding aspects of robotic milking systems. Todd encourages dairy producers not to be scared of robotic milking systems. Greg looks forward to research in the next 5-10 years to support or refute the preconceived notions we have about robotic systems. Trevor reminds listeners that cows must consume a certain amount of nutrients in order to produce milk. In the robotic system, those nutrients are delivered via two different components and research continues to understand the interplay between them. Lastly, animal behavior is a critical component of the success of robotic systems and our management approach should reflect that. (1:02:46)
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Dr. Cannas presented a Real Science Lecture webinar on October 17, 2023, titled “Diets of Productive Sheep & Goats: Performance & Health.” You can find the webinar recording at balchem.com/realscience.
Dr. Cannas outlines the topics he covered in his webinar, including nutritional requirement differences between small and large ruminants, particularly in late gestation. Small ruminants have a shorter gestation and are more prolific than cattle, for example, and this means they have more nutritional challenges in late gestation. Dr. Cannas covered supplementation, basal diet quality, and sorting ewes or does by number of fetuses. He also discussed how high milk-producing sheep and goats partition nutrients. (10:36)
Many people treat sheep and goats like smaller, low-producing cattle. Dr. Cannas considers this approach a big mistake. During pregnancy and lactation, sheep and goats are highly-producing animals that garner the same attention given to high-producing dairy and beef cattle. Dr. Texeira agrees and reminds the audience that just because sheep and goats are very adaptable animals doesn’t mean you should feed them low-quality diets. Jessica mentions that providing poor-quality feed may not allow the ewe or doe to meet her genetic potential. (21:51)
The panel discusses the importance of record keeping and data to evaluate management changes. (27:31)
Jessica asks about how Antonello fed rumen-protected choline in his experiments. They fed individually to ensure each animal received the correct dose but recommended to mix it into a TMR or mineral supplement for on-farm feeding. (33:12)
Izabelle asks how many groups most farms sort ewes or does into before lambing or kidding in Sardinia. Antonello says it depends on the individual farm because they are so diverse, but at least two groups, singles and twins. They may also sort based on the number of days pregnant as well. He describes some experimental results from feeding rumen-protected choline to ewes carrying singles versus twins. (35:35)
Dr. Teixeira describes some of the challenges sheep and goat producers face in her native Brazil due to heat stress. Jessica gives examples of management strategies to help manage heat stress based on her work at Cornell. (41:14)
The panel discussed challenges with body condition scoring goats using a sheep scale since goats store more fat internally or in other locations like the tail. They also discuss recommendations for target body condition scores at different stages of the production cycle. (48:00)
In summary, Jessica recommends that sheep and goat producers focus on what they do well, make small changes to improve their operation, and collect data to see what is working and what is not working. Izabelle encourages producers to understand what is happening physiologically in each stage of production to best manage nutritional challenges. Antonello reiterates that sheep and goats should be given the same attention and care as high-producing dairy cows. It is a complex business and there is much room for improvement in the management of small ruminants. (57:27)
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