Microbial interventions to improve gut health in neonatal calves

Scour is one of the gastrointestinal diseases in newborn calves and one of the main reasons for antimicrobial usage in the dairy industry. Previous studies reported that colostrum feeding not only transfers maternal antibodies to neonatal calves but also enhances the colonization of beneficial microbes in the gut. Failure to transfer passive immunity (FTPI) via colostrum, increases the risk of developing enteric infections such as scours during early life, a common concern in the dairy industry. Therefore, it is essential to identify effective approaches to improve calf gut health that increase the resilience to enteric infections and reduce antimicrobial use in the industry, especially during FTPI. Microbial intervention during early life has been suggested as a potential effective management approach to create a long-term effect on animal health. However, knowledge is limited on early life microbial interventions on gut microbiota colonization and gut physiology in calves with FTPI. This study hypothesizes that bovine-derived probiotics or prebiotics supplementation during early life can create a favorable environment for the colonization of beneficial microbiota and improve host resilience to enteric infections when calves experience FTPI. In this 35-d study, newborn calves (n = 50) will be assigned to one of the 2 treatment groups: (1) suboptimal transfer immunity (SO; n = 40) with 1/4 of their recommended IgG and (2) optimal group (n = 10) with the recommended level of IgG via colostrum within 2 h of birth. Calves in SO will be randomly assigned to one of the 4 treatment groups during the first 2 weeks of life: (1) probiotic (10⁹ cfu; Bifidobacterium), (2) prebiotic (80 g; resistant potato starch), (3) synbiotic, and (4) control. We will study the dynamics of gut microbiota, oxidative stress, and metabolites to explore the gut health of calves during the first 5 weeks of life. This study will help to develop effective management strategies to improve gut health while reducing preweaning calf morbidity and mortality.

Key Words: dairy calves, gut health, microbial interventions.

Published in the proceedings of the 10th Symposium on Gut Health in Production of Food Animals 2022, St. Louis, USA.