Growing in Silvopastoral System Does Not Affect the Performance or Carcass and Meat Characteristics of Lambs Finished in Feedlot

The aim of this study was to evaluate performance, feed efficiency, carcass and meat characteristics of sheep in feedlot coming from silvopastoral system during dry season in Jaboticabal, state of São Paulo, in Brazil. For the growth phase, twenty-four lambs (23 ± 2.4 kg BW) were distributed into three treatments: Unshaded (UN)= unshaded Massai grass (Panicum maximum × Panicum infestum) pasture; Moderate Shading (MS)= Massai grass pasture with eucalyptus trees spaced 12 × 2m; Intense Shading (IS)= Massai grass pasture with eucalyptus trees spaced 6 × 2m, where they stayed for 60 d. Subsequently, lambs were individually housed in feedlot pens for 30 d. Animals were fed one diet (18.2% CP and 2.8 Mcal ME/Kg of DM), containing 40% corn silage and 60% concentrate (corn grain, DDGS, soybean meal, urea, and vitamin-mineral premix). When lambs reached approximately 30 kg BW, animals were slaughtered. After evisceration the hot carcass weight (HCW) was obtained, hot carcass yield was calculated, and temperature (T0h) and pH (pH0h) were measured. Also, a cut between 12th and 13th rib was performed to expose myoglobin of Longissimus muscle to oxygen, and thirty minutes later, the meat color (luminosity [L*0h], intensity of red [a*0h] and yellow [b*0h]) was read. Measurements were also taken 24 h after slaughter (chill period at 4^oC): cold carcass weight (CCW), used to estimate the cold carcass yield, meat color (luminosity [L*24h], intensity of red [a*24h] and yellow [b*24h]), temperature (T24h) and pH (pH24h). Data were analyzed using the MIXED procedure of SAS, and the treatment means were compared using Tukey test at 5% significance. The DM intake was similar among treatments (1.14 kg; P > 0.005) as well as the average daily gain (0.30 kg; P > 0.005), and consequently, no differences in feed efficiency were observed (0.272; P > 0.05). No differences were observed in the HCW (14.1 kg), CCW (13.9 kg), neither for their yields (45.5 and 44.8 %, respectively). Thus, color (L*0h = 29.6, L*24h = 33.2; a*0h = 12.6, a*24h = 13.2; b*0h = 2.3, b*24h = 3.9), pH (pH0h = 6.4, pH24h = 5.7), and temperature (T0h = 34.2, T24h = 4.8^oC) did not differ among treatments (P > 0.05), and the averages observed in the present study were considered adequate for all variables. The silvopastoral system used during the growth phase did not affect the performance, feed efficiency or carcass and meat characteristics of lambs finished in feedlot.