Circadian Rhythm Enhances mTORC1/AMPK Pathway-Mediated Milk Fat Synthesis in Dairy Cows via the Microbial Metabolite Acetic Acid

Livestock may respond differently to circadian rhythms, leading to differences in the composition of the animal products. Nevertheless, the circadian effects on rumen microorganisms and animal products are poorly understood. In the study, it was found that dairy cows exhibited increased milk fat levels, decreased acetic acid concentrations in the rumen fluid, and elevated acetic acid levels in the blood during the night compared to those of the day. Correlational analyses suggested a high association between