The current study aimed to investigate the effects of corn silage inoculation and dietary supplementation with amylolytic enzymes, and their interactions, on feed intake, apparent digestibility, and microbial protein synthesis in wethers. Whole-crop corn forage was ensiled either with water (untreated) or with Lactobacillus plantarum MA 18/5U at 1 × 10 5 cfu/g fresh forage combined with Bacillus subtilis AT553098 at 1 × 10 5 cfu/g fresh forage (inoculated). Eight ruminally cannulated Dorper × Santa Inês crossbred wethers were used in a double 4 × 4 Latin square design. Wethers were assigned to one of four diets, as follows: 1) untreated corn silage with no amylolytic enzyme supply (US-NE); 2) untreated corn silage with amylolytic enzyme supply (US-WE); 3) inoculated corn silage with no amylolytic enzyme supply (IS-NE); and 4) inoculated corn silage with amylolytic enzyme supply (IS-WE). α-Amylase (602 dextrinizing units/kg of dry matter (DM)) was supplied to the wethers at total mixed ration delivery. Dietary supplementation with amylolytic enzyme increased (P = 0.045) DM and starch (P = 0.014) intake in wethers fed the US diet (+245 and +136 g/d, respectively), but not in those fed the IS diet. Inoculation of corn silage (P = 0.026) improved organic matter (OM), crude protein (CP), neutral detergent fiber (aNDFom), and gross energy (GE) digestibility by 5.3%, 11.5%, 25.8%, and 7.1%, respectively. Likewise, enzyme supply increased (P = 0.042) the apparent digestibility of DM, OM, CP, aNDFom, and GE by 5.1%, 4.7%, 9.4%, 20.7%, and 6.2%, respectively. Enzyme supply increased the molar proportion of propionic acid (P = 0.002; 24.1 vs. 19.6 mM / 100 mM) in wethers fed the US diet, but not in those fed the IS diet. Enzyme supply decreased microbial N synthesis (P = 0.025; 6.33 vs. 8.05 g/d) when the wethers were fed the IS diet, but not the US diet. In conclusion, despite the improved OM digestibility, dietary supplementation

The objective of this research was to investigate the effects of inoculation of corn silage and dietary supplementation of amylolytic enzymes, and their interaction, on lamb growth performance and carcass and meat traits. Whole-crop corn forage was treated either with water (untreated) or with Lactobacillus plantarum MA 18/5U at 1 × 10 5 cfu/g fresh forage combined with Bacillus subtilis AT553098 at 1 × 10 5 cfu/g fresh forage (inoculated) and ensiled for 170 d. Forty non-castrated Texel × Dorper male lambs were arranged in a randomized block design (n = 10) and then assigned to one of four diets, as follows: 1) untreated corn silage with no amylolytic enzyme supply (NI-NA); 2) untreated corn silage with amylolytic enzyme supply (NI-WA); 3) inoculated corn silage with no amylolytic enzyme supply (WI-NA); and 4) inoculated corn silage with amylolytic enzyme supply (WI-WA). α-Amylase (602 dextrinizing units/kg of dry matter (DM)) was supplied to the lambs at total mixed ration delivery. Inoculation of corn silage increased (P = 0.003) both digestible energy (DE) and metabolizable energy (ME) intake by 1.4 and 1.2 MJ/kg DM, respectively, and also resulted in higher average daily gain (ADG; P = 0.023) of lambs (233 vs. 212 g/d in lambs fed NI diet). In contrast, dietary supplementation with amylolytic enzymes had no effect on the DM intake (P = 0.90) or ADG (P = 0.15) of lambs. Moreover, inoculation, enzyme supplementation, and their interaction had no significant effects on carcass traits (P ≥ 0.06), commercial cut yield (P ≥ 0.26), chemical composition of meat (P ≥ 0.13), and meat tenderness and color (P ≥ 0.11). In terms of the fatty acid composition of longissimus muscle, inoculation of corn silage increased concentrations of saturated fatty acids (SFA; P = 0.035) from 46.2% to 47.6%, and reduced concentrations of unsaturated fatty acids (UFA; P = 0.035) from 53.8% to 52.5%, compared to the NI diet. Inoculation also reduced the UFA:SFA ratio (P = 0.031) from 1.17 to 1.11, a small but significant difference. Dietary supplementation with amylolytic enzymes did not alter (P ≥ 0.09) SFA, UFA, and polyunsaturated