The Broad Impacts of the Immune System on Dairy Cattle Production

Phibro Animal Health Corporation hosted the 2017 Pre-Conference Symposium at the Cornell Nutrition Conference in East Syracuse, NY, focusing on “The Broad Impacts of the Immune System on Dairy Cattle Production.” Over 330 attended the symposium. Presenters for the symposium shared research of their own or others as it relates to specific areas within immunity.

“As efficient and complex as the dairy cattle immune system is, studies have shown that its function can be compromised by a variety of factors,” said Dr. Jim Chapman, Director of Research and Technical Services for Phibro. “Many of these factors, such as dry-off and calving, are known and predictable, whereas others, as illustrated in the pre-conference symposium, are not as predictable and can occur at any time. All of these immunological stressors, of course, increase the opportunity for disease and reduce productivity.”

Barry Bradford, Ph.D., Kansas State University, presented a discussion on “Immunity, Inflamation and the Transition Cow.” Dr. Bradford noted that it is normal and healthy for the cow to have an inflammatory response in the transition period, but that an excessive or prolonged period of inflammation impairs animal health and performance. He highlighted a study conducted in Brazil (Brandão et al., 2016), where cows fed OmniGen-AF® nutritional specialty product from, had increased milk yield after calving associated with an appropriate inflammatory response. Tanya Gressley, Ph.D., University of Delaware, shared the causes and impacts of  Sub-Acute Rumen Acidosis (SARA), along with strategies to reduce SARA during her presentation “Immunity and Ruminal Acidosis/Laminitis.” One strategy included was the use of OmniGen-AF to help improve the immune system, which can lead to a reduction in  the systematic inflammatory response, despite changes in the ruminal environment and absorptive tissue in the digestive tract that occurs during SARA.

Wrapping up the pre-conference symposium was University of Florida researcher and professor, Geoff Dahl, Ph.D., and Dr. Robert Collier, Ph.D., University of Arizona, who spoke on “Immunity and Heat Stress in Dry and Lactating Cows.” These presenters discussed the negative effects of heat stress during the dry period on subsequent health and performance of both the cow and calf (Dahl), as well as the effects on respiration, body temperature, feed intake and milk yield in lactating cows (Collier).  Dahl shared research results showing cows that were heat stressed during the dry period produced significantly more milk in the subsequent lactation when fed OmniGen-AF before, during, and after the dry period (Fabris et al., 2017).  He also showed research in which calves born to cows that were heat stressed during the dry period were smaller at birth, had impaired immune status, and produced less milk in first lactation compared to calves born to cows cooled during the dry period. Calves born to cows fed OmniGen-AF had improved measures of immune status (Skibiel et al., J. Dairy Sci. 100:7659-7668).  Collier showed research demonstrating that lactating cows fed OmniGen-AF have higher dry matter intake and lower body temperatures during heat stress periods than cows not fed OmniGen-AF, and this change in thermoregulation was associated with hormonal changes in cows fed OmniGen-AF.

“Reducing stress in dairy cows should be a priority as it helps improve productivity and health as well as provides for the general well-being of the cow,” says Dr. Chapman. For more information on OmniGen-AF please visit or call 800.677.4623 and be put in contact with a Dairy Technical Specialist.