Development of Rumination in the Young Calf

Abstract

Rumination was observed for a full day every 2 weeks in 26 calves from 1-2 to 15-16 weeks of age. Rumination began in 18 calves in the first 2 weeks, 25 in the second 2 weeks, and in all calves in subsequent periods. Rumination time increased rapidly to an average of 5 hours per day at 6 to 8 weeks of age. Thereafter the rate of increase in rumination time was reduced. Rumination time was positively correlated with dry feed consumption, but less time per pound of feed was spent ruminating as the calves aged. The appearance of rumen contents of 17 calves sacrificed at 12 to 22 days of age indicated that more than half of the calves were ruminating effectively at 2 weeks of age. The times spent eating and drinking and lying down were correlated with blood glucose content and rumination time.