Effects of ruminal pH on gene expression in the rumen epithelium, peripheral blood 4 mononuclear cell subpopulations, and blood metabolites from Holstein calves during 5 weaning transition

In this 2019 paper published in The Journal of Veterinary Medical Science, the authors found feeding the only starter to calves decreases rumen pH at weaning with upregulation of the receptor TLR4. Feeding only starter lowered cholesterol synthesis in the rumen epithelium whereas starter and forage combined resulted in higher energy status.

By Yo-Han KIM, Noriyuki TOJI, Keiichiro KIZAKI, Kei TAKEMURA, Shiro KUSHIBIKI, Shigeru SATO