Effect of pearl millet silage ammoniated with urea on lamb production and metabolic performance

The objective of this study was to determine the effect of diets containing pearl millet silage ammoniated with urea on the intake, digestibility, production performance, and nitrogen metabolism of lambs. Thirty-two uncastrated mixed-breed lambs at 4 to 5months of age, with an average initial body weight of 17.39 +/- 2.16kg, were distributed into four treatments in a randomized block experimental design with eight replicates. Experimental diets consisted of pearl millet silage ammoniated with urea during ensiling at the levels of 0, 20, 40, and 60g/kg dry matter (DM). Increasing urea levels in the pearl millet silage led to a linear decrease (p<.05) in the intakes of DM, organic matter, and total digestible nutrients by the lambs. Total and average daily weight gains decreased linearly (p<.05) with the addition of urea to the silage. Intake and digestibility of crude protein, nitrogen intake, urine urea nitrogen, plasma urea nitrogen, microbial synthesis, and microbial efficiency had a quadratic response (p<.05) to the urea levels in the silage. Pearl millet silage ammoniated with urea reduces dry-matter intake and daily weight gain in lambs. Urea is not recommended for use in the ensiling of pearl millet.