Resumo:
In order to evaluate the effect of diets containing silages of different tropical forages on carcass characteristics and not housing components, the qualitative aspects of the flesh and the activity of enzymes evaluators liver function in sheep without defined breed, 32 lambs were used uncastrated without defined breed, with average initial weight of 17.61 ± 2.63 kg, in a completely randomized design with four diets and eight replications. The experiment was conducted at the Brazilian Agricultural Research Corporation (EMBRAPA) in the municipality of Petrolina-PE, with a trial period of 59 days and slaughtered at average weight of 27 kg. The treatments consisted of diets containing different forage silage (treatments): Saltbush (Atriplex nummularia Lind), Buffel grass (Cenchrus ciliaris), Gliricidia (Gliricidia sepium) and Pornunça ( Manihot sp) Data were submitted to analysis of variance and the means compared by 5% Tukey test method shall also the Pearson correlation and principal component analysis among the variables in the flesh. For carcass characteristics were observed lower mean for the animals fed silage Buffel grass in body condition (1.81), slaughter weight (22.64 kg), hot carcass weight and cold (9.64 and 9.42 kg), carcass conformation (1.56), state greasing (1.75), renal fat (1.56), neck (0.456), palette (0.821), rib (1,118) and rib income (24.875 ). In the evaluation of meat it was found that meat from animals fed with salt grass silage and grass Buffel had a more tender meat (1.15 and 1.16) and higher cooking loss (40.59 and 36.86) . The moisture and protein percentages were influenced by silage (P <0.05) being the saltbush silage and pornunça those with the lowest moisture (74.59 and 4.73) and the protein was observed to lower average Buffel grass (22.99) and Pornunça (22.96). In sensory evaluation was found greater acceptance for samples from lambs fed saltbush silage, which showed better results for the color parameters (4.1), flavor (4.65) and juiciness (5.09). While there has been the influence of diets enzymes ALT and AST (P <0.05), effect on unverified GGT (P> 0.05), but the serum all tested enzymes remained within the parameters physiological normality for the sheep. It was found (P> 0.05) effect of diets containing different silage tropical forages in total protein and albumin concentrations. However, urea and creatinine levels were affected (P <0.05), with the latter variable levels below those recommended in the literature for ovine species.
Different silage used can be used to feed the lambs in the semiarid. Buffel grass silage provided a lower carcass weight. The best results in the evaluation of carcass characteristics and non carcass components were with saltbush and pornunça silage.
Silages containing different tropical forages do not cause deleterious effect on hepatic metabolism, the energy profile and protein metabolism in relation to liver and kidney function and can be used as a source of roughage in diets of feedlot finished lambs.
