Our objective was to evaluate the effects of supplementing 1mg of 25-OH vitamin D3 (HyD®) and increased vitamin E amount (2000 mg/animal/d) on cattleˈ performance and carcass characteristics when fed a 90-d feedlot finishing diet. A total of 140 Nellore bulls (IBW = 387 ± 28 kg) were distributed in 14 pens (10 animals/pen) in a randomized complete block design (7 pens per treatment). The basal diet was composed by 15% sugarcane bagasse, 72.8% ground corn, 7.6% soybean meal and 4.6 % mineral-vitamin premix (DM basis). The dietary treatments were: 1) Control: No addition of 25-hydroxy-vitamin-D3 (HyD®) and basal Vit. E amount (520 mg/animal per day); 2) HyD+Vit.E: Addition of 1 mg of HyD® plus increased Vit. E amount (2000 mg/animal per day). The animals were fed once daily and had free access to fresh water. Statistical analysis was performed using the MIXED procedure of SAS 9.4. Means comparison was evaluated by tukey test and declared significant at P < 0.05, and tendencies considered when 0.05 < P < 0.10. There was no difference on final body weight (~522.8 kg, P = 0.11), ADG (~1.54 kg/d, P = 0.17), DM intake (~9.9 kg/d, P = 0.41) and G:F (~0.156, P = 0.28) between treatments. Likewise, no differences were observed (P > 0.10) for dressing (~53.5%), REA (~65.5 cm²) and SFT (~4.10 mm). However, feeding HyD+Vit.E tended to increase (P = 0.07) carcass average daily gain (0.993 vs. 0.953 kg/d) and increased (P = 0.04) carcass weight by 4.2 kg compared with control (281.6 vs. 277.4 kg). In conclusion, the combination of HyD and increased vitamin E increases carcass production in feedlot cattle.

Our objective was to evaluate the effects of feeding 3-nitrooxypropanol (3-NOP; Bovaer®, DSM Nutritional Products) at two levels on methane emissions, nitrogen balance and performance by feedlot cattle. In exp. 1, a total of 138 Nellore bulls (iBW, 360 ± 37.3 kg) were housed in pens (27 pens with either 4 or 5 bulls per pen) and fed a high-concentrate diet for 96 days, containing 1) no addition of 3-NOP (control), 2) inclusion of 3-NOP at 100 mg/kg DM, and 3) inclusion of 3-NOP at 150 mg/kg DM. No adverse effects of 3-NOP were observed on DM intake, animal performance and gain:feed (P > 0.05). In addition, there was no effect (P > 0.05) of 3-NOP on carcass characteristics (subcutaneous fat thickness and rib eye area). In exp. 2, 24 bulls (iBW, 366 ± 39.6 kg) housed in 12 pens (two bulls/pen) from Exp.1 were used for CH4 measurements and nitrogen balance. Irrespective of the level, 3-NOP consistently decreased (P < 0.001) animals’ CH4 emissions (g/d; ~ 49.3%), CH4 yield (CH4/DM intake; ~40.7%) and CH4 intensity (CH4/ADG; ~38.6%). Moreover, 3-NOP significantly reduced the gross energy intake lost as CH4 by 42.5% (P < 0.001). The N retention: N intake ratio was not affected by 3-NOP (P = 0.19). We conclude that feeding 3-NOP is an effective strategy to reduce methane emissions, with no impairment on feedlot cattle performance.

The objective was to evaluate the effects of feeding levels of an exogenous carbohydrases blend on performance and carcass characteristics of grazing Nellore beef cattle. A total of 168 bulls were distributed to twenty Brachiaria brizantha cv. Xaraés paddocks (8 or 10 animals/paddock) in a randomized complete block design, with five replicates (paddocks) per treatment. Bulls were assigned according initial BW (IBW; 369.07±21.13 kg) to receive treatments for 231 days: 1) Control (basal mineral-protein-energetic supplement, no enzyme; PES), Carb1 (PES + 0.83 g of xylanase, RONOZYME® WX; and 3.09 g of beta-glucanase, RONOZYME® VP, both offered/kg PES), Carb2 (PES + 1.65 g of xylanase and 6.18 g of beta-glucanase/kg PES) and Carb3 (PES + 3.30 g of xylanase and 12.38 g of beta-glucanase/kg PES). Evaluated parameters were final BW (FBW), average daily gain (ADG), supplement intake, hot carcass weight (HCW) and dressing %. IBW and FBW were measured after a 12-hour fastening period. Treatments were offered daily in covered group feeders located in each paddock. Animals had free access to supplements and water. Supplements and enzymes were provided by DSM Nutritional Products. Data were analyzed using MIXED procedure of SAS® 9.3, being each paddock the experimental unit. Orthogonal contrasts were used to detect linear and quadratic effects on enzyme levels, with values P ≤ 0.05 considered significant. No linear or quadratic effects (P > 0.05) were observed on supplement intake (2.11 kg/animal/d), FBW (492.03 kg) and ADG (0.532 kg/day). However, a quadratic effect was observed for HCW and dressing %, with animals fed Carb1 presenting 5.69 kg heavier carcass (272.67 vs. 266.98; P = 0.039) and 1.4 p.p. higher dressing % (55.3% vs. 53.9%, P < 0.001) compared with control group. In conclusion, to use carbohydrases enzyme blend improves carcass characteristics and is an interesting technology for Nellore beef cattle grazed in tropical conditions.

Our objective was to evaluate the effects of feeding increasing exogenous carbohydrases levels on cattleˈ performance, when fed a 90-d feedlot finishing diet. A total of 240 Nellore bulls (IBW = 389 ± 27 kg) were distributed in 24 pens (10 animals/pen), in a randomized complete block design (6 pens/treatment). The basal diet was composed by 15% sugarcane bagasse, 72.8% ground corn, 7.6% soybean meal and 4.6 % mineral-vitamin premix (DM basis). The treatments were: 1) control: No addition of carbohydrases blend; 2) Blend1, in g/animal/d: 1 g of Ronozyme® WX (xylanase) + 3.75 g of Ronzyme® VP (beta-glucanase); 3) Blend2, in g/animal/d: 2 g of Ronozyme® WX + 7.5 g of Ronzyme® VP and 4) Blend3, in g/animal/d: 4 g of Ronozyme® WX + 15 g of Ronzyme® VP. The animals were fed once a day and had free access to fresh water. Statistical analysis was performed using the MIXED procedure of SAS 9.4, and comparisons were performed out by orthogonal contrasts, which compared the control and treatments, and the linear and quadratic effects of the increasing carbohydrases levels. Statistical significance was declared at P < 0.05, and tendencies considered when 0.05 < P < 0.10. Animals fed carbohydrases had greater (P = 0.045) ADG (1.59 vs. 1.51 kg/d) and tended to have greater (P = 0.069) final BW (533.4 vs. 527.7 kg) compared with control; although no difference were observed on these variables among carbohydrases levels. Feeding carbohydrases increased DM intake, expressed either as kg/d (10.17 vs. 9.92; P = 0.019) and as percentage of BW (2.20 vs. 2.16 %; P = 0.038), compared to control group, respectively. However, no difference was observed among treatments on G:F, and dressing percentage. In conclusion, the addition of carbohydrases blend can improve performance of finishing cattle.

Our objective was to evaluate the effects of feeding 3-nitrooxypropanol (3NOP; Bovaer®, DSM Nutritional Products) at two doses on methane emissions and performance by feedlot cattle. The experiment was designed as a completely randomized block, in which 138 Nellore bulls (iBW, 360 ± 37.3 kg) were placed in collective pens (9 pens per treatment) and fed a high-concentrate diet (R:C, 11:89) according with the following three treatments: 1) 0ppm 3NOP /day; 2) 100ppm 3NOP/day, or 3) 150ppm 3NOP/day. For performance and DMI assessments the pen was the experimental unit. For methane emission evaluations, CH4 and DMI were assessed individually in 12 pens (2 bulls/pen, 8 bulls (experimental units)/treatment). Methane emission was measured for 6 consecutive days using the sulfur hexafluoride (SF6) tracer technique in two times over the experimental period (d15d -d21) and (105d to 111d), whereby the gross energy (GE) variables were calculated using equations. The individual DMI was measured using the two markers technique (Chromium oxide and indigestible NDF). The data were analyzed using the Mixed procedure of SAS and means comparison were carried out by Tukey’s test. Regardless of the level, dietary supplementation with 3NOP decreased (P < 0.001) methane emissions by 49.7% as expressed as g/d (146.0 vs. ~74 g/d−1); by 38.6% when expressed as g/kg ADG (91 vs ~56 g/kg ADG), and by 40.7% when expressed as g/kg DMI (13.5 vs. ~8 g/kg DMI). Likewise, dietary supplementation with 3NOP decreased (P < 0.001) the GE loss as a percentage of the GE intake by 42.4% (4.74 vs ~2.73%). However, feeding 3NOP had no effect on animalsˈ DM intake (~2.43 %BW; P = 0.23), ADG (~1.52 kg/d; P = 0.11) and HCW (~284 kg, P = 0.26). We conclude that Bovaer® can be used to effectively reduce methane emission by feedlot cattle without adverse effects on performance.