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

On this week’s episode of Diving into Diets Dr. Brad White and Dr. Philip Lancaster discuss a 2025 study on grazing behavior in cattle, focusing on factors like age, size, hide color, and forage quality. The study tracked 40 cows using GPS collars over three years, finding that older cows traveled further distances, possibly due to learning topography. Red cows traveled more in cold temperatures due to better heat retention from black hides. The study also noted that cows traveled further to high-quality forage areas, as measured by NDVI and IRG, and up slopes and to water sources. The study’s individual hypothesis testing approach limited the interpretation of confounding variables like production stage and weather.

Article Discussed: https://www.sciencedirect.com/science/article/abs/pii/S1871141325001258?via%3Dihub 

Dr. Brad White and Dr. Bob Larson discuss the failure of passive transfer in beef herds, highlighting differences from dairy cattle. Risk factors included calves born to heifers, twins, and assisted births. Higher body condition scores in cows also correlated with lower IgG levels. The study emphasized the importance of colostrum intake, especially in high-risk situations. The discussion emphasizes the need for targeted management strategies in beef cattle.

Article Discussed: https://pmc.ncbi.nlm.nih.gov/articles/PMC2643452/

In About the Abstract, the experts discuss a study by Cordial and Carrie (2024) in the Journal of Animal Science, which compared the impact of metaphylaxis with Tulathromycin versus saline on high-risk beef stocker calves over 42 days. The study found that calves treated with Tulathromycin had higher average daily gain, especially in the first 14 days, and fewer treatments for respiratory disease. Culture results showed more bacteria in saline-treated calves at follow-up. Antimicrobial use was higher in the Tulathromycin group, but the number of regimens was similar. The study suggests that metaphylaxis may improve health and performance while managing antimicrobial resistance.

Featured Article: https://pubmed.ncbi.nlm.nih.gov/38126883

In this episode of BCI Cattle Chat, guest Dr. Cassandra Olds continues the discussion of Theileria, a tick- and fly-borne parasite affecting U.S. cattle herds. The team explains how it spreads from the East Coast westward, causes anemia-like symptoms, and persists for life in infected animals. They stress prevention through stress reduction, parasite control, and good nutrition, noting that no approved treatment exists. The conversation shifts to preparing heifers for breeding season, emphasizing pre-breeding exams, tracking weight and reproductive readiness, and managing nutrition to ensure early conception and lifelong productivity.

Dr Cassandra Olds Contact Information:

34A Waters Hall
Manhattan KS 66506
Phone: (785) 706-8599
Fax: (785) 532-6232

[email protected]