Digestibility and performance of lambs fed diets containing old man saltbush hay.

The aim of this study was to evaluate feed intake, digestibility, nitrogen balance, water balance, and performance of lambs fed diets containing old man saltbush hay associated with a concentrate. Thirty-two castrated feedlot Santa Ines lambs at approximately eight months of age, with 22 ± 1.97 kg body weight, were distributed into a completely randomized experimental design. Acid detergent fiber intake increased (P < 0.05), whereas non-fibrous carbohydrates intake decreased (P < 0.01). Inclusion of old man saltbush in the diet reduced (P < 0.01) the digestibility of dry and organic matter, neutral and acid detergent fiber, and non-fibrous carbohydrates. The intakes of digestible dry and organic matter, ether extract, total carbohydrates, and digestible non-fibrous carbohydrates also decreased (P < 0.01). Inclusion of old man saltbush did not influence water consumption from the trough by the sheep, averaging 4,327.20 mL/day?1. Body weight at slaughter and daily weight gain decreased linearly (P < 0.05) and feed conversion worsened as old man saltbush hay was added to the diet. Inclusion of old man saltbush at up to 40% replacing the concentrate in feedlot lamb diets does not compromise the performance of these animals.