Chewing efficiency and body size of kid goats

Thirty-two observations were made on 27 goats (18 mature, nonlactating females and 9 doe kids) to study the relationship among metabolic body size (body weight X 75), cell wall constituent intake, and chewing efficiency. A jaw motion recorder determined the minutes spent eating and ruminating during 24 h. Greater cell wall intake increased the amount of cell wall chewed per minute. Body size was directly related to cell wall eaten and ruminated per minute. In 2- and 3-mo-old kids, incomplete development of rumen function and body size both appeared to affect chewing efficiency. The chewing efficiency of 9-mo-old kids resembled that of the mature goats after adjustments for body size. Because rumination time seldom exceeds 10 h per day, the efficiency with which the time available for rumination is used will affect intake.