Effects of supplementation on the calving interval of Canchim cows

Abstract

The objective of this study was to evaluate the effects of a constant level of protein supplementation, offered through 700 g of soybean meal per head/day and sugar-cane ad libitum, on the reproductive efficiency of first-calving Canchim heifers. Seventy-eight cows, averaging 430 kg of liveweight and three years of age, were randomly assigned to four treatments: (T) control on pasture; (S) pasture with protein supplementation; (C) pasture with sugarcane; and (C + S) pasture with protein and sugarcane. The supplementations were offered during the dry period (June to September), on Paspalum notatum and Digitaria decumbens pastures. The results showed that animals on treatments C + S and S maintained weight during the dry season, while those on treatments C and T lost, on the average, 34kg and 24kg of liveweight, respectively. Animals on treatment C + S showed a shorter (P<0.01) interval from parturition to first estrus than those on treatments S and T, while animals on treatment C had a shorter interval than those on T. No statistical differences were found on the other variables studied, however there was a slight tendency for a superiority of treatments C + S.