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

Abstract

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 Inês 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 Inês 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.

Growth Performance, Eating Behavior, Digestibility, Blood Metabolites, and Carcass Traits in Growing-Finishing Fat-Tailed Lambs Fed Different Levels of Dietary Neutral Detergent Fiber with High Rumen Undegradable Protein

“…Nonetheless, decreasing levels of dietary NDF increased HCW and hot dressing percentages linearly. This is coherent with the findings of Silva Moura et al [44], where a lower proportion of roughage in the diet resulted in heavier SBW, HCW, and CCW in feedlot lambs. In a study ofSantos-Silva et al [45], however, SBW, HCW, and CCW of lambs were not influenced by various levels of dietary NDF.…”

“…Inconsistent with Silva Moura et al [44], decreasing dietary NDF concentration had no effect on the moisture percentage of deboned carcasses, which was likely because of no differences in slaughter weight obtained with the present diets. Crude protein concentration in deboned carcasses decreased linearly with decreasing NDF concentrations, whereas ether extract changed quadratically with the highest values in NDF220.…”

“…Papi et al [1] observed that decreasing dietary forage levels did not affect skin, head, kidney, lung, and spleen weights but changed feet, heart, and liver weights in growing fat-tailed lambs. In a study bySilva Moura et al [44], lambs fed on a high-roughage diet had lighter empty gastrointestinal tract weight, empty body weight, and internal fat.…”

“…However, Papi et al [1] reported that decreasing the forage level of diet did not affect the weights of most carcass cuts, but tail fat weight decreased for lambs fed a higher proportion of dietary forage. Silva Moura et al [44] reported that a high dietary proportion of forage did not change the weights of feedlot sheep's shoulders, rib, loin, and leg.…”

Dietary Supplementation of Yeast Culture Into Pelleted Total Mixed Rations Improves the Growth Performance of Fattening Lambs

“…In most YC supplement studies where even yeast is active, slaughter performance does not change (5,65). An increased ADG, as occurred in this study, does not necessarily translate to improved slaughter performance (66,67). Another reason is that in most slaughter trials, six to eight lambs are applied to detect treatment differences, which do not have enough power to detect a moderate response.…”