Nutritional performance and metabolic characteristics of cattle fed tropical forages with protein and starch supplementation

• Autor(a) principal: Franco, Marcia O.
• Data de Publicação: 2021
• Outros Autores: Detmann, Edenio, Batista, Erick D., Rufino, Luana M. A., Paulino, Mario F., Valadares Filho, Sebastião C.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFLA
• Texto Completo: http://repositorio.ufla.br/jspui/handle/1/50022
• topic: Brachiaria decumbens; Digestibility; Fiber; IGF-1; Low-quality hay; Nitrogen balance; Plantas forrageiras tropicais; Nutrição animal; Bovinos - Digestibilidade; Fibras; Feno de baixa qualidade; Balanço nitrogenado

Effects of protein supplementation, with and without starch supplementation, on nutritional performance and metabolic characteristics of cattle fed low- and medium-quality tropical forages were evaluated using 4 cannulated steers distributed according to a 4 × 4 Latin square. Experimental periods were divided into two subperiods. In the first subperiod, two animals received low-quality hay and two animals received medium-quality. Supplementation schemes were evaluated in the second subperiod: low-quality hay with protein (300 g of crude protein – CP/d); low-quality hay with protein (300 g CP/d) and starch (225 g/d); medium-quality hay with protein (300 g CP/d); and medium-quality hay with protein (300 g CP/d) and starch (225 g/d) supplementation. Without supplementation, medium-quality forage provided higher intake, digestibility, nitrogen balance (NB) and efficiency of nitrogen utilization (EFNU). Comparing subperiods, supply of supplements depressed medium-quality forage intake, but did not affect low-quality forage intake. Supplementation increased NB, EFNU and serum concentration of IGF1 in animals fed low-quality forage. Protein supplementation increases nitrogen retention in animals, an effect attributed mainly to anabolic stimuli. However, this effect is more prominent when animals are fed low-quality forages. No positive impact on animal metabolism was obtained with combination of supplemental protein and starch.