Increasing levels of concentrate supplement in the postweaning period of steers on tropical pasture during the rainy season

The intensification of cattle post-weaning phase in tropical pastures depends on supplementation strategies. The objective of this study was to assess the effect of increasing levels of concentrate supplement on the intake, apparent digestibility of nutrients, feeding behavior, and performance of Girolando steers on tropical pasture during the post-weaning phase in the rainy season. Forty uncastrated male Girolando steers, initially weighing 266.62 +/- 32.95 kg and aged 11 mo, were allocated into four concentrate supplement levels: 0.2%, 0.3%, 0.4%, and 0.5% body weight. The steers grazed on Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster 'Marandu' pasture. The intakes of supplement DM, non-fibrous carbohydrates (NFC), and total digestible nutrients increased linearly (P < 0.05) with the level of supplement offered to the steers. In a similar response, the apparent digestibility of DM and NFC from the diet also rose linearly (P < 0.05). Grazing time, total feeding time, and total chewing time decreased (P < 0.05) with the increasing levels of concentrate supplementation. In contrast, the time expended on feeding at the trough, biting rate, and the time taken to ruminate each cud increased (P < 0.05) with the supplementation level. Final body weight and average daily gain increased linearly (P < 0.05) with increasing concentrate supplementation. We recommend supplying concentrate supplement at a level of 0.5% of the body weight of steers on tropical pasture during the post-weaning phase in the rainy season.