Successfully Developing High-Performing Heifers with Dr. Mike Van Amburgh from Cornell University

10/22/24 • 65 min

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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This Real Science Exchange podcast episode was recorded during a webinar from Balchem’s Real Science Lecture Series.

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undefined - Sustainable Livestock, Sustainable Future: Why We Need a Toolkit of Solutions to Improve Sustainability in Animal Agriculture with Dr. Mitloehner & Dr. Nichols; UC Davis

Sustainable Livestock, Sustainable Future: Why We Need a Toolkit of Solutions to Improve Sustainability in Animal Agriculture with Dr. Mitloehner & Dr. Nichols; UC Davis

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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Next Episode

Epidemiology - Understanding Dairy Studies with Dr. Daryl Nydam, Cornell University; Dr. Stephen LeBlanc, University of Guelph

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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