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This study was carried out to evaluate the effect of ensiling sorghum silage with urea and amending the aerobic exposure nutrients intake and apparent digestibility, ingestive behaviour and blood serum metabolites of feedlot lambs. Forty uncastrated crossbred Dorper × Santa Inês lambs, aged 150 ± 15 days and with an initial body weight of 21.73 ± 2.40 kg, were used. Animals were assigned in a 2 × 3 factorial arrangement. Thus, six silage diets were produced with various urea addition levels (UA: 0 and 5 g/kg on a natural matter basis) and periods of aerobic exposure of silages (PAE: 0, 24 and 48 h). An effect was observed for nutrient intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre corrected for ash and protein (NDFap) and total digestive nutrients TDN (g/day) and for the total apparent digestibility of DM, OM and CP. There was an interaction effect between urea levels and aerobic exposure for ether extract (EE) and NDFap intakes (g/kg) and nonfibrous carbohydrate (NFC) digestibility (g/kg) (p = 0.012). The addition of 5 g/kg of urea to sorghum ensilage improved the digestibility parameters without changing dry matter intake and ingestive behaviour. The addition or not of urea does not change the blood parameters of the animals.

The whole corn germ (WCG), due to its desirable nutritional characteristics, has been studied as feed for ruminants. This study aimed to evaluate the effects of WCG inclusion as a linoleic acid source in diets for feedlot lambs on carcass characteristics, physicochemical composition, sensory attributes, and fatty acid profile of the meat. Forty non-castrated, crossbreed Dorper x Santa Inês lambs were distributed in a completely randomized design to evaluate the inclusion levels (0, 30, 60, 90, and 120 g/kg dry matter (DM)) of whole corn germ (WCG) in the diet. The dietary inclusion of WCG did not influence (p > 0.05) the weight gain and carcass characteristics, with the exception of the subcutaneous fat thickness (p < 0.01), which was higher in animals fed diets with higher levels of WCG. Lightness (L *; p = 0.04), yellowness (b *; p < 0.01), shear force (p = 0.04), linoleic fatty acid concentrations (p = 0.03), and total polyunsaturated fatty acids (p = 0.04) had a quadratic increase due to WCG inclusion in the diets. The use of up to 120 g/kg DM of WCG in lamb diets does not affect the carcass characteristics, physicochemical composition, and sensory attributes of the meat. Despite this, the best polyunsaturated fatty acid profile in lambs’ meat is obtained using 76.7 g/kg DM of WCG.