On this episode of Tox Talk, Dr. Brad White and Dr. Scott Fritz discuss a case where eight bred cows were moved into a barn ahead of a winter storm and were found dead the next morning. While initial concerns focused on the barn environment, testing revealed the cause was acute nitrate poisoning from newly introduced millet hay containing high nitrate levels. Nitrate toxicity can cause rapid death, often within hours, and may leave few obvious signs. This case is a reminder to consider what has changed when sudden losses occur, especially feed sources. Certain forages, including millet and other stress-grown crops, can accumulate nitrates, and toxicity persists after baling. Testing unfamiliar or newly purchased hay can help prevent devastating losses.

In this episode of Diving into Diets, the discussion examines how different phosphorus and calcium diets affect phosphorus retention, milk composition, calf growth, and bone status in beef cattle. While cows on lower-phosphorus diets maintained milk production and calf growth in the short term, they mobilized phosphorus from bone, unlike cows on high-phosphorus, high-calcium diets. The takeaway is that cows are resilient and can tolerate short-term deficiencies, but inadequate long-term mineral intake may eventually impair performance, underscoring the need for appropriate supplementation.

Article Discussed: https://era.dpi.qld.gov.au/id/eprint/14721/1/AN24216.pdf

This episode of Herd Health explores how cattle producers and veterinarians can choose the most effective estrus synchronization and fixed-time AI protocols for heifers and cows. Dr. Bob Larson explains that there is no single “best” protocol. Instead, the right choice depends on factors such as whether you are dealing with heifers or cows, time available, group size, handling logistics, and cost. The discussion highlights the roles of progesterone, GnRH, and prostaglandin, compares common protocols, and emphasizes using trusted resources such as the Beef Reproduction Task Force and working closely with veterinarians to ensure proper execution and consistent results.

Beef Reproduction Task Force

In this episode of About the Abstract, Dr. Brad White and Dr. Todd Gunderson discussed a study that tested whether water intake can predict bovine respiratory disease (BRD). The study’s main finding was that water intake decreased 1–2 days before BRD treatment or diagnosis. The study also found that the amount of water consumed mattered more than the number of visits or the time spent at the waterer. The cattle treated multiple times for BRD consistently drank less water than healthy cattle. The main takeaway from the study was that monitoring water intake per visit to the waterer is more important than monitoring cattle behavior.

Article Discussed: https://www.sciencedirect.com/journal/preventive-veterinary-medicine

On Dividing into Diets, Dr. Brad White and Dr. Philip Lancaster explore how a ruminant’s diet influences the production of volatile fatty acids (VFAs), such as acetate, propionate, and butyrate, created through the fermentation of carbohydrates and proteins in the rumen. They explain that different types of feed support different bacterial populations, shifting the balance of VFAs. For example, grain-heavy diets boost propionate levels, while high-forage diets favor acetate. Despite these shifts, overall animal efficiency depends more on the total amount of volatile fatty acids produced than on the specific proportions. The experts note that attempts to manipulate VFA ratios can be expensive and often yield only minor improvements in productivity.

On today’s episode of Herd Health, Dr. Brad White and Dr. Bob Larson discuss how to choose the best synchronization protocol for artificial insemination in cattle. They explain the differences between protocols for heifers and cows, including timing, hormone use, and management considerations. The discussion highlights the importance of resources like the Beef Reproduction Task Force website and factors such as chute time, cost, and herd size.

Episode Resource: https://beefrepro.org/

On Herd Health, Dr. Brad White and Dr. Bob Larson discuss a 2025 study in the Canadian Journal of Animal Science on factors influencing heifer replacement and cow-calf profitability. The study focused on cow feed efficiency, longevity, heterosis, and lifetime productivity. Key findings include the importance of longevity, with heifers staying longer in the herd being more profitable. Crossbreeding, particularly those with more heterosis, reduced costs. Residual feed intake (RFI) was crucial, with lower RFI cows being more efficient and cost-effective. The study used data from 2011 to 2018, accounting for economic fluctuations, and found no significant differences between breeds.

Article Discussed: https://www.researchgate.net/publication/385812533_Effects_of_cow_feed_efficiency_longevity_heterosis_and_lifetime_productivity_on_profitability_of_heifer_selection_and_cow-calf_operations

Dr. Brad White and Dr. Todd Gunderson discuss a study on bovine coronavirus and its role in respiratory disease in cattle. The study, published in Frontiers in Veterinary Science, used a challenge model with 15 challenge calves and six control calves. Results showed higher viral shedding in challenge calves. PCR detected bovine coronavirus in multiple tissues but not in the lungs or tracheobronchial lymph nodes. Histopathology scores indicated more pathology in challenge calves, but clinical signs were mild. The study suggests bovine coronavirus may play a role in mild respiratory disease but not in severe pneumonia, possibly acting as a co-factor for secondary infections.

Article Discussed: https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2022.878240/full