Effect of the exclusive use of pasture on the performance of early-weaned beef calves

The objective of this experiment was to study the performance of beef calves weaned at 93.1 days of age, at an average weight of 84.1 kg, using pasture as the only source of feed. Treatments consisted of: T1-native grassland and winter pasture (PINI); T2-elephantgrass and winter pasture (CEPI); T3-bermudagrass cv. Coast-cross-1 and winter pasture (BEPI); and T4-pearl millet and winter pasture (MIPI). Calves were kept on summer pasture from February 7, 1991 to May 1, 1991. During the winter and spring (May 2, 1991 to October 10, 1991) all animals were grazed together on native grassland in paddocks resown with oats, annual ryegrass, and Yuchi arrowleaf clover. The pastures were grazed continuously with a variable number of animals. In addition to the eight tester animals, put-and-take animals were added to maintain forage availability. The experimental design was completely randomized with two replications during the summer period. In the winter, each calf was considered an experimental unit. Weight gains during the experimental period (236 days), were 83.7, 102.5, 110.5, and 105.0 kg for PNPI, CEPI, BEPI and MIPI, respectively. There were no differences among CEPI, BEPI, and MIPI, which were higher than PNPI. Under the experimental conditions, the use of pasture that included natural grassland as the only source of feed for early-weaned calves resulted in inferior performances when compared to cultivated pastures.