Effects of Monoterpenoid Exposure on Ability of Rumen Inocula to Digest a Set of Forages

Abstract

Rumen inoculum collected from wild mule deer on summer, fall, winter, and spring ranges in central Utah was equally effective in digesting alfalfa hay, orchardgrass hay, big sagebrush, curlleaf mahogany, antelope bitterbrush, and hips of sweetbrier rose. Alfalfa hay was the forage most easily digested. Inocula from deer that had not been exposed to big sagebrush and juniper monoterpenoids (essential oils) digested all test forages, including big sagebrush equally as well as inoculum from deer that had been exposed to big sagebrush monoterpenoids. We concluded that rumen microorganisms do not have to adjust to the presence of the monoterpenoids or other dietary changes.