Strategies of energy supplementation for cattle fed tropical forage and infrequently supplemented with protein

Our objective was to evaluate the effects of different energy supplementation strategies in Nellore heifers fed tropical grass forage and infrequently supplemented with nitrogen (N) compounds on voluntary intake, digestion, ruminal fermentation and fibre dynamics, urinary excretion characteristics, N balance, and hormonal and blood metabolic profile. Five rumen and abomasum fistulated Nellore heifers, averaging 332 kg of body weight, were used in a 5 × 5 Latin square design. The five treatments were: control, without supplementation; supplementation of 660 g of crude protein (CP) every 3 days; supplementation of 660 g of CP every 3 days and daily supplementation with 440 g of starch; supplementation of 660 g of CP and 1320 g of starch every 3 days; and supplementation of 660 g of CP and 1320 g of starch every 3 days, but starch supplementation was performed one day after CP supplementation. On average, treatments did not affect (P > 0.44) voluntary forage intake. However, the forage intake varied over the three-day supplementation cycle. Forage intake was depressed (P