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The influence of concentrate supplementation during the dry and rainy seasons on performance of young Nellore bulls grazing tropical grass pastures

Evellyn Aryanne Diniz, Terry Engle, Edenio Detmann, Natália Lacerda, Kharina Santana, Robson Ribeiro, João Rodrigues , Kaliandra Alves, Luis Rennan de Oliveira, Jenifer Maira Ramos, Rafael Mezzomo, Daiany Gomes

Abstract

Context. In the tropics, there is a substantial demand for a broader understanding of the impact of supplementation strategies on animal growth. Aims. The aim of this study was to evaluate the effects of different concantrate supplementation strategies during the dry, rainy, or both seasons on intake, digestibility, performance, and carcass weight of young Nellore bulls. Methods. Twenty−eight young Nellore bulls with an initial average live weight (LW) of 327  4.2 kg of were used. Animals had ad libitum access to a Urochloa brizantha pasture and a mineral mixture sequentially in dry and rainy seasons. Treatments consisted of four concentrate supplementation strategies: (i) no concentrate supplementation (−/−); (ii) 8 g/kg LW in rainy season (−/+); (iii) 8g/kg LW in dry season (+/−); (iv) 8g/kg LW in both dry and rainy seasons (+/+). Key results. Forage intake was lesser (P<0.05) in cattle fed +/+ when contrasted against all other supplementation strategies. In the dry season, concentrate supplementation increased (P<0.04) LW gain from 0.40 to 0.74 kg∙animal-1∙day-1. Considering performance in both the dry and rainy seasons, all supplementation strategies increased (P<0.05) total LW gain, hot carcass weight, carcass fat and muscle when compared to the negative control treatment −/−. Bulls receiving +/+ had greater (P < 0.05) total LW gains and hot carcass weights compared to −/+ and +/− treatments.. Directly contrasting −/+ and +/−, supplementation in the rainy season tended (P<0.10) to increase total LW gain and hot carcass weights. Conclusions. Concentrate supplementation decrease forage intake but increase LW gain, hot carcass weight and carcass quality. Concentrate supplementation in both the dry and rainy seasons provide greater LW gain and hot carcass weights than concentrate supplementation during only the dry or rainy seasons. Concentrate supplementation only during the rainy season produced greater hot carcass weights and LW gains compared to concentrate supplementation only during the dry season. Implications. Under the conditions of this experiment, to achieve maximum LW gains and hot carcass weights, concentrate supplementation should be provided during both dry and rainy seasons. If supplementation costs are a limiting factor, the results indicates that concentrate supplementation during the rainy season provides greater LW gains and carcass weights than concentrate supplementation only during the dry season. However, pasture nutritive value, carcass prices and supplement costs must be evaluated before selecting a supplementation strategy.

AN24375  Accepted 27 June 2025

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