Rumen Volume as a Factor Involved in Individual Sheep Differences

Publisher Website
Google Scholar
Abstract
Estimations of rumen volume using Cr2O3 were made with eleven 3-year-old wethers fed semipurified rations. Nitrogen (as casein and urea nitrogen in the ratio of 2:1) was increased in 1-gm. steps from 10 to 20 gm. of N daily. At the conclusion of this experiment daily nitrogen intakes were reduced to 6 gm. Finally, the animals were slaughtered and a number of measurements made on the rumen and its contents. It was shown that, while sheep weights ranged from 61.8 to 75.5 kg., rumen physiological volumes varied between 2.5 and 7.6 liters. A significant (P<.01) positive correlation was found between sheep weight and the empty rumen weight; between ad libitum intakes of material low in nitrogen and physiological rumen volume; between the physiological volume and the physical capacity of the rumen; between rumen weight and the physical capacity of the rumen; and between estimated rumen volume and physiological rumen volume, propensity to eat and the reciprocal of the dilution value of Cr2O3 from immediately prior to feeding until 8 hr. after feeding. It is suggested that vastly different ecological rumen environments may exist, when sheep with different rumen volumes are fed at the same level of feed intake and, further that this change in environment may influence both microbiological and rate of passage studies. Copyright © 1966. American Society of Animal Science . Copyright 1966 by American Society of Animal Science