Carcass characteristics of semi-confined lambs in integrated production systems

Integrated production systems can intensify sheep production, optimizing the use of supplements for grazing animals, and thereby, resulting in better finished carcasses of young animals. The aim of this study was to evaluate the effects of intercropping of a tropical grass with legume, and different systems of oat seeding on carcass characteristics of lambs in semi-confinement in the year of 2014 in Botucatu, S?o Paulo, Brazil. Forty-eight lambs (initial BW = 27.0 ? 3.2 kg) were used in a 68 d trial, in a completely randomized design. Treatments were distributed in a 2 x 2 factorial arrangement, with 2 types of silage (S): corn silage with marandu grass {Brachiaria brizantha (Hochst. ex A. Rich.) Stapf cv. Marandu} and pigeonpea (Cajanus cajan cv. BRS Mandarim) (P) and without pigeonpea (WP), 2 types of over seeding black oat (BO): in line (Li) or broadcasted (Br). Animals spent the day grazing in the black oat and the night, they were herded to a barn, separated by treatments in collective pens, and it were offered concentrate and silage of their respective diets. Live fasting weight (LWF), ruminal content (RC), hot carcasses (HCW) and cold carcasses were weighed (CCW) to assess the empty body weight (EBW, kg = LWF - RC), hot carcasses yield (HCY, % = HCW/LWF x 100) and cold carcasses yield (CCY, % = CCW/LWF x 100), and real yield (YR, % = (HCW/EBW) x 100). It were measured the pH, temperature (T), and subcutaneous fat thickness (SFT) of Longissimus dorsi muscle. Data were submitted to analysis of variance using MIXED procedure of SAS, and when differences were found, the Tukey test (P <= 0.05) was applied, considering animal as the experimental unit. There were observed no differences among treatments for all variables studied or interactions (P > 0.05), and means and standard errors found were pH = 5.75 and 5.80; 5.76 and 5.78 ? 0.02, T (^oC) = 17.33 and 17.30; 17.48 and 17.14 ? 0.45 and SFT(mm) = 1.40 and 1.19; 1.33 and 1.26 ? 0.12 for S (P vs. WP) and BO (Li vs. Br), respectively. In conclusion, corn silage intercropped with marandu grass and pigeonpea did not affect carcass characteristics of lambs in semi-confinement of integrated production systems of South-Central region of Brazil.