Energy sources in diets for lambs in confinement

Context. The use of alternative sources in ruminant feeding features advantages such as diminished dependence on traditional cereals that can be used for human consumption or monogastric animals. Aims. This study was conducted to examine nutrient intake, apparent digestibility, mean growth rate, nitrogen balance, and microbial protein synthesis in lambs fed diets containing different energy sources in the concentrate. The experiment involved five uncastrated Santa Ines lambs, with an initial BW of 22.85 +/- 1.0 kg, which were allocated individual metabolic cages and randomly assigned to one of the following five experimental treatments: maize (MA), wheat bran (WB), sorghum (SO), mesquite pod meal (MP) and peach palm meal (PP) in a 5 x 5 Latin square design, with five replicates each. Diets were isoenergetic with a roughage:concentrate ratio of 60:40. Key results. The energy sources in the concentrate influenced (P < 0.0001) the intakes of DM and nutritional components. The apparent digestibility coefficients of the ether extract and NDFap were significantly (P < 0.05) different between WB and the other diets. The different energy sources in the concentrate (MA, WB, SO and MP) increased (P < 0.0001) the mean growth rate of the lambs. The diet containing PP as an energy source provided a smaller (P = 0.0002) N intake than that from any other diet, and the PP diet resulted in a negative N balance (P = 0.0200). Lambs fed with diets containing MP (80.38 g day(-1)) as an energy source showed a larger (P = 0.0007) microbial protein synthesis than did those fed with PP (24.47 g day(-1)). Wheat bran, sorghum, and mesquite pod meal can completely replace maize for lambs fed diets based on 270 g kg(-1) of maize. A variety of unusual feed ingredients facilitates the raising of lambs in various regions, with ingredients being local and of the lowest cost, promoting benefits to sheep producers.