Different roughage:concentrate ratios and water supplies to feedlot lambs: carcass characteristics and meat chemical composition

The current study evaluated the effects of dietary roughage:concentrate (R:C) ratios and water supply on the carcass characteristics and yield of lambs. Forty Santa Ines crossbred lambs with an average body weight (BW) of 19 ± 2.8 kg were evaluated in a completely randomized design with a 2 × 2 factorial arrangement consisting of two proportions of roughage and concentrate (30:70 and 70:30) and two levels of water supply ( ad libitum and restricted to 0.5). The animals were slaughtered at an average weight of 28 ± 31 kg. Centesimal composition, colour parameters (L*, a* and b* ), shear force, cooking losses and pH were determined on the Longissimus lumborum muscle. There was no interaction effect between the R:C ratio and water supply on the evaluated variables. Total BW gain, average daily gain and final BW were affected by water restriction and R:C ratio. Water restriction reduced total BW gain, average daily gain and final BW. No effect of water restriction was detected on slaughter weight, centesimal composition, colour variations, shear force, pH, weight or yield of carcass. No effect of water restriction and diets was observed on the cuts, except for neck weight. Carcass weight and yield were affected by the R:C ratios. Restricting the water supply to 0.5 does not affect the carcass weight or yield of Santa Ines crossbred lambs or their meat quality characteristics (centesimal composition, colour, shear force and pH measurements). A higher proportion of concentrate in the diet results in heavier hot and cold carcass weights.