Effects of dietary microbial feed supplement on production efficacy in lactating dairy cows

Summary: Conventional dairy probiotics often comprise microbes isolated from the environment, not from the gastrointestinal tracts of ruminants; thus, their capacity to influence cow performance is limited. We tested the effects of dietary microbial feed supplementation on production efficiency and quality in lactating dairy cows using microbes native to the rumen environment. Microbial feed supplementation (MFS) had little to no effect when all cows were considered. However, a retrospective analysis demonstrated that lower-producing cows had increased energy-corrected milk and tended to have increased milk and fat yields, along with increased lactose percentage over time, whereas higher-producing cows had decreased milk yield, increased milk protein percentage, and increased body condition score when fed MFS.