135 Growth Performance, Carcass Characteristics, and Methane Emissions of Feedlot Young Bulls

Abstract The growth performance, carcass characteristics, and methane emissions from feedlot beef cattle fed a high-lipid finishing diet (7.3% of ether extract) were evaluated. Fifty long-yearling young bulls divided into two groups following their breed composition: Nellore (n = 25) Angus × crossbred 25), randomly assigned 4 pens (12 or 13 animals/pen) completely randomized design. Animals sourced the same breeding season endured grazing growing phase in Megathyrsus maximus cv. Mombaça pasture, with protein energy supplement offered at 0.2% body weight (BW). comprehended 105 days feed, (80% concentrate) was formulated to meet safely exceed requirements target an average daily gain (ADG) 1.6 kg/day, which major ingredients represented by (% DM basis): sorghum silage (20%), ground corn (57.6%), soybean seed as lipid source (20.4%), mineral/vitamin premix (2%). Titanium dioxide (TiO2) used external marker estimate dry matter intake (DMI), while 10 g administered 12 animals each group, once daily, for d. weighed every 30 d after 16-h fasting period, day before slaughter obtain final (FBW). Enteric measured using sulfur hexafluoride (SF6) tracer gas technique measurements. equipped collection halters attached pre-evacuated polyvinyl chloride (PVC) sampling canisters capillary tube (0.127 mm diameter), made permit 50% filling 24 h, five consecutive days. Data analyzed statistical analysis software R (R CORE TEAM, 2021), effect on traits evaluated design one-way, treatment means compared F test (P < 0.05). had greater DMI (12.6 vs.0.6 kg/d), efficiency (0.16 vs. 0.14), initial BW upon (509.8 444.7 kg), FBW (720.8 595.6, ADG (2.01 vs..44 hot (404.7 345.0 kg; P 0.01) cattle. No difference observed dressing percentage between genetic 0.28). produced more expressed CH4 g/kg (266.0 vs.73.4; 0.01), tended produce kg/DMI (35.4 27.7; 0.08), CW (1.09 0.87; 0.11). Crossbred F1 Nellore/Angus showed improved performance weight, not negatively affecting total production, but rather lessening per unit produced.