Evaluation of grazing beef cows receiving supplements with different protein contents

• Autor(a) principal: Lopes, Sidnei Antônio
• Data de Publicação: 2016
• Outros Autores: Paulino, Mário Fonseca, Detmann, Edenio, Rennó, Luciana Navajas, Valente, Ériton Egídio Lisboa, Cabral, Carla Heloísa Avelino, Carvalho, Victor Valério de, Lima, Josilaine Aparecida da Costa, Manso, Marcos Rocha, Bonfá, Hugo Colombarolli
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://dx.doi.org/10.5433/1679-0359.2016v37n5p3361; http://www.locus.ufv.br/handle/123456789/18637
• topic: Beef cows; Intake; Nellore; Non-esterified fatty acids; Supplementation

The aim of this study was to evaluate the effects of supplementation with different crude protein contents on the productive performance of grazing beef cows during post-calving. Thirty-six beef cows, with age and average body weight of 5 years and 490±17.9 kg, respectively, were used. The experimental design was completely randomized. The treatments were: control = cows received only mineral mixture ad libitum; supplemented = cows received 1 kg d -1 of supplement containing 80, 200, or 320 g crude protein (CP) kg -1 . There was no effect (P ≥ 0.16) of supplementation on voluntary intake. A linear effect (P < 0.02) of the CP content in the supplements was observed among supplemented cows, only for the CP intake. Supplementation did not affect (P ≥ 0.20) the total digestibility of organic matter, neutral detergent fiber corrected for ash and protein, and CP. Among supplemented cows, a positive linear effect (P < 0.01) of the CP content in the supplement was observed for the CP digestibility. Intestinal flow of microbial nitrogen compounds and efficiency of synthesis microbial were not affected (P ≥ 0.18) by treatments. Performance, milk yield and composition were not also affected (P ≥ 0.11) by treatments. Supplementation did not affect (P ≥ 0.52) non-esterified fatty acids, urea nitrogen and progesterone serum concentrations. It is concluded that supplementation of grazing beef cows during post-calving does not affect nutritional and productive performance.