Carcass traits and meat quality of lambs fed with rehydrated ground corn silage

Abstract

Rehydration and ensiling are methods to processing and preserving corn grains by which starch digestibility, nutrient availability, animal performance, and meat quality can be improved. The objective of this study was to evaluate the effect of the substitution of ground corn by rehydrated ground corn silage (RGCS) in high-concentrate diets for feedlot lambs on performance, carcass traits, and meat quality. Forty Santa Inês non-castrated male lambs were used, with an initial average body weight of 21 ± 2.8 kg (mean ± standard error) and an age of approximately 4 months. Lambs were distributed in a completely randomized design, corresponding to five treatments and eight repetitions. The treatments consisted of substitute RGCS for ground corn at levels of 0, 250, 500, 750, and 1000 g/kg of dry matter (DM) in the concentrate. The sampling and data collection (experimental period) lasted 64 days. At the end of the experimental period, the animals were subjected to a solid fast, followed by slaughter. To evaluate meat quality, both longissimus lumborum muscle were collected. The substitution of ground corn by RGCS in high-concentrate diets did not alter (P > 0.05) the meat pH, cooking losses, tenderness, juiciness, aroma, and global acceptance of meat from feedlot lambs. However, the ground corn substitution by RGCS increased linearly lightness (P = 0.016), redness (P = 0.005), yellowness (P = 0.026), and flavor (P = 0.018) of the meat. On the other hand, the shear force was linearly reduced (P = 0.003). The ground corn substitution by RGCS had no effect (P > 0.05) on the fatty acid profile and the hypocholesterolemic to hypercholesterolemic fatty acid ratio of the lambs' meat. Therefore, considering the current results, ground corn can be completely replaced by rehydrated ground corn silage in high-concentrate diets for feedlot lambs.