Substitution of commercial concentrate by mulberry forage (Morus alba cv. Linn) in the ration of fattening tropical Pelibuey lambs.

International audienceThe effects of substituting concentrate by chopped and fresh homeground mulberry forage were evaluated in an experiment with fattening lambs lasting 126 d from weaning. The basal forage diet was composed by Pennisetum purpureum, Panicum maximun ‘Likoni’ and sugarcane. Forty-eight entire Pelibuey lambs (initial BW 20.6 kg) were randomly allocated in 4 experimental groups according to treatments which consisted on the level of supplementing (or not) the basal diet with mulberry forage: M-1: mulberry at 1% of BW (DM basis); M-0.75: mulberry at 0.75% plus 0.1 kg/lamb/d of concentrate; M-0.50: mulberry at 0.50% plus 0.2 kg of concentrate; and M-0: supplementing basal diet with 0.3 kg of concentrate (Control). Average daily gain (ADG, g/d) was significantly affected (P < 0.01) by the supplementation regimen with M-1 lambs yielding the lowest ADG (100.2 g/d). No differences in ADG among the other groups were observed (124.7; 125.4 and 128.9 g/d for the treatments M-0.75, M-0.50 and M-0, respectively). Feed conversion was 11.6, 9.9, 10.3 and 9.7 kg DM/ kg of BW gain for M-1, M-0.75, M-0.50 and M-0 lambs, respectively. Differences in final BW at slaughtering and hot or cold carcass yields were coherent with those found in growth performance. Supplementing with mulberry forage at 0.75% of BW was the feeding alternative showing the best productive response