Microorganisms that live in the digestive system of cattle help break down food, improve nutrient absorption, and can even affect how much methane the animals produce. These microbes may also influence traits important to beef production, such as meat quality and animal growth. In this study, we examined the gut microbiome, the community of bacteria and archaea, in Nellore bulls, the predominant beef cattle breed in Brazil. Our goal was to understand how these microorganisms relate to traits like feed efficiency, body size, and muscle area. We identified over 1,300 bacterial and archaeal taxa and found that some were more common in animals with better performance. For example, specific bacteria were linked to larger ribeye muscle area and higher metabolic weight. Our results show that the gut microbiome is not only diverse but also closely connected to important production traits. This suggests that by understanding and possibly modifying the microbiome through breeding, nutrition, or management, farmers could improve animal health and productivity. However, more studies are needed to fully understand how these microbes influence the animals’ biology.

Read the full article in the Journal of Animal Science.