- Animals: bovine
- Animal Production: animal protection and health, probiotics
Calf diarrhea is one of the biggest challenges in both the dairy and beef industry worldwide. In the U.S., between 4 and 25 percent of calves die from diarrhea each year. The increased intestinal permeability and disturbance of gut microbiota are key factors leading to the pathogen-induced diarrhea. Brahman cattle contribute substantially to beef production in the southern region of the U.S. through crossbreeding, due to their heat tolerance and disease resistance. The heat stress can induce the damage of intestinal barrier dysfunction, but it is largely unclear whether the heat-tolerant Brahman calves have a more integrated intestinal epithelium that contributes to their resistance to diarrhea. Our preliminary studies found that fewer pathogens and mucin-degrading bacteria but more beneficial butyrate-producing commensals colonized in the gut of Brahman calves compared with Angus calves. Fecal microbiota transplantation from diarrhea-resistant livestock has been reported to relieve diarrhea of recipients. Here, we raised a hypothesis that gut microbiota of Brahman calves contributes to diarrhea resistance and strong mucus barrier through suppressing pathogenic bacteria and mucin-degrading bacteria. Our objectives are 1) to isolate potential probiotic strains from diarrhea-resistant Brahman calves and test their antimicrobial activity; and 2) to evaluate the efficiency of potential probiotic strains on the reduction of diarrhea and investigate its mechanisms regarding regulation on the gut microbiota structure and intestinal mucus barrier function. The outcome of this study will reduce diarrhea and benefit the southern beef and dairy industry by uncovering the underlying secrets of the local disease-resistant animals.
Project objectives from proposal:
- To isolate potential probiotic strains from diarrhea-resistant Brahman calves and test their antimicrobial activity.
- To evaluate the efficiency of potential probiotic strains on the reduction of diarrhea and investigate its functional mechanisms in terms of regulation on the gut microbiota structure and intestinal mucus barrier function.