Effects of soybean silage on feeding behavior, performance, and meat quality of lambs

The objective of this study was to evaluate the performance, feeding behavior, carcass traits, and meat quality of feedlot lambs using 2 types of silage, sorghum or soybean. Twenty-eight male non-castrated market lambs weighting 20 +/- 2 kg were used. Diets were formulated to be isonitrogenous and isocaloric. The animals were slaughtered after 50 days of experiment, with 32.13 +/- 5.09 kg of body weight. Lambs fed with soybean silage showed increased time for feed intake (P = 0.01). There was no difference for allowed daily gain, dry matter intake, feed conversion, and carcass traits between diets. Meat from lambs fed with soybean silage showed decreased shear force (P = 0.001) compared to sorghum silage, with no differences (P > 0.05) for chemical composition, color, and cooking loss. The intake of sorghum silage increased (P < 0.05) C6:0, C16:0, C20:0, C14:1, and C16:1 fatty acids content of Longissimus lumborum intramuscular fat. The intake of soybean silage showed an increased (P < 0.05) content of C18:1 omega 9t, C18:2 omega 6c, and sum of omega 6 fatty acids. The feed cost and profit from the use of sorghum and soybean silage were US$ 0.12 and US$ 0.13/Lamb/d, US$ 16.68 and US$ 16.97/Lamb, respectively. The use of soybean silage provides the same performance and carcass traits of lambs compared with sorghum silage, and it shows the benefit of decrease shear force and the proportion of hypercholesterolemic fatty acids C16:0 and C16:1.