Effect of nickel and protein concentration on consumption and apparent digestibility of dry matter, crude protein, energy, and nitrogen balance of a Brachiaria brizantha cv. Marandu hay, in ovines

This study was carried out to evaluate the effect of nickel supplementation and protein concentration of the diet on dry matter intake and apparent digestibilities of dry matter, crude protein (CP) and energy, and nitrogen balance of male sheep fed on Brachiaria brizantha cv. marandu hay. The experimental diets were: A-hay; B-hay + nickel; C-hay + protein; D-hay + nickel + protein. The diets contained 0.2, 5.2, 0.5 e 5.5ppm of nickel and 3.1, 3.1, 8.2 and 8.2% of crude protein, respectively. No effect of nickel supplementation on the apparent digestibility of dry matter, energy and protein, as well as the balance of protein and energy were observed for lower protein concentration diets ( A and B; 3.1% CP). The nickel supplementation reduced the digestible dry matter, digestible energy and metabolizible energy consumption of higher protein concentration diets (C and D; 8.2% CP). The protein concentration of diets increased all the studied parameters, independently of nickel supplementation, except the apparent digestibility of crude energy, which were similar for B and D diets.