Performance of F1 Red Angus Nellore heifers in different nutritional plans during breading and rearing on pasture

Os objetivos foram avaliar o desempenho de novilhas F1 Red Angus × Nelore em diferentes planos nutricionais durante a cria e recria. Foram utilizadas 34 bezerras com 127 dias de vida médios e peso médio de 153,90 kg distribuídas em fatorial 2x2. Na cria foram avaliados os tratamentos controle (mistura mineral) e suplementados em creep-feeding (0,5% do PV), e na recria foram avaliados 2 níveis de oferta de suplemento: Baixo (0,1% do PV) e alto (0,5% do PV). Na terminação as novilhas foram submetidas ao mesmo nível de suplementação (2% do PV) em sistema de terminação intensiva a pasto. Foram avaliados peso, GMD e produção de leite das mães durante a cria e, nas bezerras o peso, GMD, características sanguíneas ao final da cria, recria e terminação e, após abate foram mensurados PCF, PCQ, RC, AOL e EGS. Todas as avaliações foram realizadas com o MIXED do SAS 9.4, e adotou-se 0,10 como nível crítico de probabilidade para o erro tipo I. O peso ao desmame, o GMD e a produção de leite das mães foram similares (P>0,10) entre os tratamentos na cria. Bezerras suplementadas ao creep tiveram maior (P0.10) between treatments. Calves supplemented with creep had higher (P<0.10) weight and ADG at weaning. Total cholesterol, HDL, LDL, creatinine, GOT and GTP levels were lower (P<0.10) in supplemented calves, while urea was higher (P<0.10). In rearing phase there was an effect on the level of supplementation, where the high level resulted in higher weight and ADG (P<0.10). There was a creep effect that resulted in a lower level (P<0.10) of total cholesterol, and an effect of the supplementation of rearing, where the high level resulted in higher (P<0.10) levels of glucose, total cholesterol, HDL, VLDL, triglycerides, urea, albumin and IGF1. At finishing phase, there was no effect of the previous phases and no interaction between them, except for slaughter weight, which was influenced by supplementation in rearing (P<0.10), where the high level resulted in higher slaughter weight. There was an interaction between creep and supplementation regarding GOT levels (P < 0.10). It is concluded that the creep-feeding results in additional gain, as well as higher levels of supplementation in rearing phase, and such treatments have blood characteristics that indicate better nutrient supply. However, such gains may be lost in subsequent phases in case of reduced levels offered. Keywords: Creep-feeding. Intensive grazing finishing. Supplementation.Conselho Nacional de Desenvolvimento Científico e Tecnológic