Real Science Exchange

• Feeding Rumen-Protected Choline During the Peri-Conceptional Period Programs Postnatal Phenotype of Calves with Dr. Masroor Sagheer, University of Florida and Dr. Pete Hansen, University of Florida

  Dr. Hansen’s lab conducted several in vitro experiments where choline chloride was supplemented to beef embryo culture media for the first seven days of embryonic development. Calves resulting from the choline-supplemented embryos were consistently 17-20 kilograms heavier at weaning. In the feeding experiment presented at the Florida Ruminant Nutrition Symposium, Dr. Sagheer fed rumen-protected choline to beef cows one day before AI through seven days post-AI, spanning ovulation, fertilization, and the first seven days of embryo development. In contrast to the in vitro studies, calves born to cows supplemented with choline during the peri-conception period were lighter at weaning than control calves. The panel discusses potential mechanisms of action for these results, including choline’s role as a methyl donor potentially impacting the epigenetic programming of the embryo.

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• Beef on Dairy Cattle - Economic Decision Making on the Farm with Dr. Corwin Nelson, University of Florida; Dr. Tara Felix, Penn State University; Dr. Brad Johnson, Texas Tech University

  This episode was recorded at the 2025 Florida Ruminant Nutrition Symposium. Dr. DeVries’ research focuses on farm-level decisions and modeling. The University of Florida dairy has implemented the use of beef semen. Dr. DeVries describes some of the factors that go into a partial budget for this system as well as details some of the factors involved in implementing beef on dairy. The UF dairy genomically tests all their cows and the panel discusses some differences in beef and dairy selection based on genomics. (5:58)Dr. Felix asks how the beef sires are selected for the UF dairy. Calving ease and fertility are key, as well as low cost. Dr. Johnson asks if spending a little more on beef semen might pay off in the longer term regarding beef quality. The panel agrees that in the current market, dairy producers are getting $800-$1000 for a day-old calf regardless of the beef sire, so perhaps beef sire selection has not been a major focus. (15:07)Dr. DeVries describes some of the data he evaluates when deciding how many cows to breed with sexed dairy semen. Given the current beef prices, heifer retention has not been as high in either the beef or dairy sector as previously predicted. (19:22)The panel discusses the importance of cow longevity in the dairy sector. Dr. DeVries explains the pros and cons of keeping cows in the milking herd longer. Dr. Nelson reminds listeners of the current cull cow market and how that also plays a role in decision-making for dairy and beef producers. (24:16)Dr. Nelson describes the heifer development program for the UF dairy. Week-old heifer calves are shipped to Kansas for development and return to UF at about 200-220 days pregnant. This approach is very common in the southeast. Many of the beef on dairy calves will also be shipped to calf ranches out of state. (30:59)Dr. DeVries’ model concluded that switching from conventional dairy to beef-on-dairy resulted in about $150 advantage per cow per year. On top of that was another $50 per cow because of the switch to sourcing your heifers from your best cows. (34:13)The panel discusses the idea of transferring beef embryos into dairy cows. Could there be a day when this approach creates beef calves less expensively than the cow/calf sector can? They also delve into whether there will be any long-term negative impacts of breeding dairy cows with beef semen. (38:44)Dr. Johnson mentions another paradigm shift of the beef-on-dairy system is feeding dairy-influenced heifers in the feedlot, which has not happened before. Technologies used to promote growth in the feed yard can induce spontaneous lactation in some of these heifers. Milk is considered an adulterant in the packing plant and requires trimming if it splashes on a carcass. Dr. Nelson suggests that until there is a discount for heifer beef on dairy calves, there won’t be a shift to using sexed male semen to create predominantly beef on dairy steers. (48:33)The panel wraps up with their take-home thoughts. (57:46)Please subscribe and share with your industry friends to invite more people to join us at the Real Science Exchange virtual pub table.  If you want one of our Real Science Exchange t-shirts, screenshot your rating, review, or subscription, and email a picture to [email protected]. Include your size and mailing address, and we’ll mail you a shirt.

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• Beef on Dairy Cattle - Advancing Beef Quality to the Next Level with Dr. Brad Johnson, Texas Tech University; Dr. Tara Felix, Penn State University

  This episode was recorded at the 2025 Florida Ruminant Nutrition Symposium. Dr. Johnson and Dr. Felix begin with brief descriptions of their background. (1:26)Dr. Johnson’s presentation at the symposium focuses on beef quality aspects of using beef sires on dairy cows. Using the same Angus semen, his research model compared Angus-sired beef calves raised in a conventional cow-calf system, Angus x Holstein calves, Angus x Jersey calves, and Angus-sired IVF beef embryos transplanted into Holstein and Jersey cows. The model evaluated how the management impacted feedlot performance and carcass quality. (6:37)Dairy-influenced beef is tender and highly marbled. It also has more oxidative fibers prone to lipid peroxidation and higher myoglobin content which gives it a redder hue. When high-myoglobin beef is in retail packaging, it goes through discoloration faster than traditional native beef, and retailers shy away from that. Beef on dairy products have a retail display life more like native beef, and large retailers are embracing that product. (10:12)Ribeye size was not different among any of the cattle groups in Dr. Johnson’s study, including straight calf-fed Holsteins. Beef on dairy calves have similar ribeye area and 0.15-0.20 inches less backfat than a straight beef calf, so their yield grades are lower, implying more red meat yield. In practice, however, they don’t have increased red meat yield compared to native beef because they give up so much muscle in their hindquarter. (14:14)Dr. Felix asks if the selection criteria of the Angus sire Dr. Johnson used may have limited the findings from a yield standpoint. Dr. Johnson agrees that was definitely the case, as they chose a high-marbling sire on purpose, and he happened to be fairly light muscled. Dr. Johnson feels that improving the plane of nutrition of beef on dairy calves in the hutch for the first 60-70 days could vastly improve hindquarter muscling later in life. (19:39)Muscle biopsies from the ribeye and hindquarter of hutch calves on low and high planes of nutrition found no difference in muscle proliferation in the ribeye. Hindquarter muscle proliferation was improved in calves on the high plane diet. Dr. Felix reiterated that there is a lack of literature in this area. (25:35)If beef on dairy calves have less backfat, does that mean they have better feed efficiency? In Dr. Johnson’s study, the best feed efficiency group was the Angus x Holstein F1 cross. Dr. Felix and Dr. Johnson discuss changes in feedlot practices and days on feed and how the industry is moving to carcass-adjusted average daily gain and feed efficiency measures. (31:14)The panelists discussed the impact of gut size on carcass value. In the dairy industry, we want cows to have high intakes for high milk production, which requires a large gut size. Dams of beef on dairy calves may pass on these traits. Dr. Johnson describes a beef calf and a beef on dairy calf out of the same sire where the beef calf was 40 pounds lighter at the end of the feeding period, yet both calves had the same hot carcass weight. That 40-pound difference was gut size. Dr. Felix and Dr. Johnson share their experiences with differences in fat and trim between beef and beef on dairy carcasses. (39:25)Dr. Felix asks Dr. Johnson how the valuation of beef on dairy calves drives marketing decisions. Day-old dairy calves are extremely valuable right now. A high index beef on dairy calf will bring $800-$1100, depending on what part of the country you live in. If a dairy producer only has $200 in that calf, they should take the money and run. There is no way they will make $800 per head feeding out those calves. (47:30)In closing, Dr. Zimmerman urges ASAS and ADSA to bring back Joint Annual Meetings so more cross-species interactions can be fostered. Dr. Felix notes there is a tremendous gap where the dairy nutrient requirements end and where the beef nutrient requirements pick up. We need to fill that gap to better target optimal muscle development in beef on dairy calves. Dr. Johnson is enthusiastic about the amount of progress the beef on dairy sector has experienced in a short period. We’re one or two tweaks away from beef on dairy carcasses rivaling native beef in quality. What we’re learning in this sector can also be applied to the native beef sector to improve meat quality and red meat yield. (56:52)Please subscribe and share with your industry friends to invite more people to join us at the Real Science Exchange virtual pub table.  If you want one of our Real Science Exchange t-shirts, screenshot your rating, review, or subscription, and email a picture to [email protected]. Include your size and mailing address, and we’ll mail you a shirt. 

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• How Beef on Dairy Selection Impacts Beef and Dairy Production with Dr. Tara Felix, Penn State University; Dr. Brad Johnson, Texas Tech University

  This episode was recorded at the 2025 Florida Ruminant Nutrition Symposium. Dr. Felix and Dr. Johnson begin with brief descriptions of their background and interest in beef on dairy research. (3:15)Dr. Felix’s first study in this area compared dairy calves with beef on dairy calves of unknown origin. They were placed in the feedlot and fed and implanted the same. Beef on dairy calves grew faster, but they ate more, so there was no difference in feed efficiency. They also had larger ribeye areas and slightly heavier carcass weights. In subsequent studies, calf growers indicated that beef on dairy calves were more hardy and got a quicker start in the calf systems. (9:16)Dr. Johnson and Dr. Felix are both fans of using Charolais sires in beef on dairy systems. Dr. Felix emphasizes that while breed can be important, individual sires within breeds really make the difference when it comes to successful beef on dairy systems. (13:23)The beef and dairy industries speak two different languages when it comes to genetic selection. Dr. Felix encourages education efforts across both segments to speak a common language. Bull studs are heavily invested in this effort. Just 2.5 million units of beef semen were sold in the US in 2017, compared to 9.4 million units in 2024. (16:15)The use of beef sires increased gestation length by two days in one study of over 10,000 dairy records. Dairy producers may have to manage the dry period of beef on dairy cows differently to avoid loss of milk production. (20:46)Last year, the National Association of Animal Breeders published a new category in their annual semen sales report: heterospermic beef, at 1.5 million straws. Genetic companies have started to market straws containing semen from two to three different beef bulls who have similar desired traits. The literature suggests that different cows’ reproductive tract environments have different “preferences” for semen. The theory behind heterospermic beef is by putting more than one bull in a straw, we may see increased fertility for that straw. (27:52)Dr. Felix explains her sire selection process from her USDA research. Regardless of breed, she focused on yearling weight, carcass weight, and ribeye area. Because of this, little difference was found between breeds since the same terminal traits were of priority. Dr. Johnson agrees that the growth of beef on dairy has been beneficial to feedlots and that the beef cattle industry can learn from the beef on dairy systems. (32:36)What challenges still exist with beef on dairy? Dr. Felix suggests we need to get past the block of dairy beef “only being 20% of the fed cattle” - why shouldn’t that 20% be as high quality as possible? Health will continue to be a challenge, particularly in the areas of liver abscesses and respiratory disease. (41:46) Adequate colostrum intake is critical for successful beef on dairy calves. Dr. Felix describes a project where calves who had adequate passive immunity were heavier at nine months of age than calves who had failure of passive immunity. Dr. Johnson concurs and reminds listeners that colostrum also contains bioactive components that appear to have value beyond immunity, even after gut closure. (44:36)Dr. Johnson gives some perspective from the cow/calf side of the beef cattle industry regarding beef on dairy. He feels that there is much to learn from beef and dairy systems that can be applied to the cow/calf sector. Dr. Felix has received pushback from cow/calf producers that she’s trying to “put them out of business.” She counters that we had 20% dairy influence in fed cattle when they were Holstein, and there is still 20% dairy influence now that they’re crossbred cattle. We’re not changing how many calves come from the dairy industry each year, but we are increasing the amount of beef produced. (47:52)Each panelist wraps up with their take-home messages. Dr. Zimmerman was interested to learn about the longer gestation lengths in beef on dairy crosses and the implications that has for drying off cows. Dr. Johnson reminds listeners not to forget about the maternal side of the beef on dairy industry. He wonders if dairy producers could select for improved muscling without a loss in milk production to make beef-on-dairy crossbred calves even more desirable to the packer. Dr. Felix comments that, at the end of the day, it’s about feeding people. The increase in beef production from beef on dairy is something to be proud of, and she hopes some of what has been learned can also benefit the cow/calf industry to improve sustainability for the entire beef supply chain. (54:16)Please subscribe and share with your industry friends to invite more people to join us at the Real Science Exchange virtual pub table.  If you want one of our Real Science Exchange t-shirts, screenshot your rating, review, or subscription, and email a picture to [email protected]. Include your size and mailing address, and we’ll mail you a shirt. 

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• The Benefits of Mitigating Heat Stress in Dairy Cattle with Dr. Lance Baumgard, Iowa State University

  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.Dr. Baumgard begins with an overview of the structure and function of the gastrointestinal tract. More than 75% of an animal’s immune system resides in the gut. The focus of this webinar is how heat stress initiates leaky gut, how that leaky gut then influences the immune and hormonal systems, and ultimately, how that reduces productivity. (0:22)Dr. Baumgard compares the metabolism of a cow 200 days in milk to a cow 10 days in milk. The 200-day cow is experiencing ad libitum intake and gaining weight. Her insulin levels would be high, and NEFAs would be low. On the other hand, the 10-day cow is experiencing suboptimal intake, and her insulin levels are the lowest they’ll ever be during the production cycle. Body tissue is mobilized, and NEFAs will increase. Research shows it takes 72 grams of glucose to make one kilogram of milk. Any disruption to the gluconeogenic pathway has the potential to decrease milk yield. (6:38)Heat stress is estimated to cost the US dairy industry $1.7 billion each year. Regardless of climate change, heat stress will continue to be an issue because all economically important phenotypes in animal agriculture are heat-producing processes. Dr. Baumgard’s lab has been investigating the biology of heat stress to implement more effective mitigation strategies. (9:09)How much of the reduction in feed intake during heat stress explains the reduction in milk yield? A pair-feeding experiment comparing thermoneutral to heat-stressed cows showed that about 50% of the reduction in milk yield during a heat wave is due to a reduction in feed intake. The thermoneutral cows lost weight in response to decreased intake, and their NEFAs increased. Heat-stressed cows did not have an increase in NEFA. Heat-stressed animals fail to mobilize adipose tissue despite their endocrine profile predicting that they should. However, insulin is high when we would expect it to be low, and that response to heat stress is highly conserved in all species. (10:43)Heat-stressed cows produced about 400 grams less lactose per day than their pair-fed thermoneutral controls. This is nearly a pound! Is the liver producing 400 fewer grams of glucose each day? Or is some other extramammary tissue using more glucose per day? Dr. Baumgard’s work suggests that the immune system is where the 400 grams of glucose go in heat-stressed animals. During heat stress, vasodilation at the body surface occurs, with concomitant vasoconstriction in the gut. The gut epithelium is very sensitive to reduced oxygen delivery that would result from the vasoconstriction, and tight junction proteins do not function properly, resulting in a leaky gut. This results in an infiltration of antigens into the body, which causes an immune response.  (15:36)Dr. Baumgard details how insulin fits into these immune responses via the Warburg effect. An activated immune cell prefers glucose and needs it in high quantities. The activated cell switches from the Kreb’s cycle to generate ATP to aerobic glycolysis. This requires high insulin. The immune system requires approximately one gram of glucose per kilogram of metabolic body weight per hour. (25:03)By far, the biggest impact a dairy producer can make to alleviate heat stress is to modify the environment physically: shade, fans, soakers, misters, etc. Investing in cooling cows improves production efficiency and profitability, summer fertility, animal welfare and health, and sustainability. Other important heat abatement considerations include adequate water availability, reducing walking distance to the parlor and time in the holding pen, and improving ventilation. Dry cows should also be part of any heat abatement strategy, as the benefits of cooling dry cows extends far into lactation. Dr. Baumgard also discusses different dietary management strategies for heat stress situations. (32:43)In summary, heat stress decreases almost every metric of productivity and costs everyone in the industry. Reduced feed intake is only part of the problem. Heat-induced leaky gut results in biological consequences incredibly similar to any other immune activation, such as mastitis or metritis. For dairy producers, heat stress abatement should by far be their biggest priority. Once those infrastructure improvements are in place, dietary interventions are another good strategy to minimize the negative consequences of heat stress. (47:43)Dr. Baumgard takes questions from the webinar audience. (49:22)Please subscribe and share with your industry friends to invite more people to join us at the Real Science Exchange virtual pub table.  If you want one of our Real Science Exchange t-shirts, screenshot your rating, review, or subscription, and email a picture to [email protected]. Include your size and mailing address, and we’ll mail you a shirt.

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