R. Bras. Zootec.07/Oct/2026;55:e20240213.
Performance of calves in dry season feedlot according to genetic group and sex
Ana Clara da Silva Severino
, Bruna Cardoso Braga
, Raphael dos Santos Gomes
, Severino Delmar Junqueira Villela
, Cláudio Manoel Teixeira Vitor
, Fernando de Paula Leonel
ABSTRACT
The aim of this study was to evaluate feedlot rearing as a strategy for beef calves during the dry season and to assess the effects of genetic group and sex on productive performance. Fifty-four calves were allocated to a completely randomized design with a 3 × 2 factorial arrangement, consisting of three genetic groups (Caracu, Nellore, and Caracu × Nellore crossbred) and two sex classes. The diet was formulated to support an average daily gain (ADG) of 0.5 kg/day. Average daily gain (ADG), dry matter intake (DMI), and feed conversion ratio (FCR) were evaluated. Data were analyzed by analysis of variance, and means were compared using the Student-Newman-Keuls test at 5% significance level. A significant interaction between genetic group and sex was observed for ADG (P<0.05). Crossbred Caracu × Nellore males showed the highest ADG (0.75 kg/day), differing from all other treatment combinations. Caracu males and Caracu × Nellore females showed intermediate ADG values and did not differ from each other, while Nellore males and females exhibited the lowest gains and did not differ between sexes. No interaction was detected for DMI or FCR (P>0.05); however, significant main effects of genetic group and sex were observed. Caracu and Caracu × Nellore calves showed greater DMI than Nellore calves, and males consumed more dry matter than females. A better feed conversion was observed in crossbred calves, followed by Caracu and Nellore calves, and males showed greater feed efficiency than females. Feedlot rearing during the dry season proved to be an effective strategy for promoting satisfactory growth rates in beef calves. Under the conditions of this study, crossbred Caracu × Nellore calves and males exhibited superior performance and feed efficiency, highlighting the importance of considering both genetic group and sex when allocating calves to intensive post-weaning systems.
Keywords: intensive rearing; nutritional strategy; seed straw