Resumen
- In Colombian Caribbean, livestock base-diet is tropical-pastures. Finding the best strategy for feeding supplements is important to enhance the animal performance. The objective of this study was to evaluate the effects of energetic-protein supplementation (ENS) on growth, bodyweight (BW) and enteric methane emission of beef cattle grazing pastures. Twenty Brahaman steers (474±34,05 kg) were distributed in four paddocks of six hectares each under a continuous stocking grazing system and assigned to a completely randomized design with four treatments: T1: grazing on Cynodon nlemfluensis (CN), T2: grazing on Brachiaria hybrid (BH); T3: CN+ENS and T4: BH+ENS. T3 and T4 received 1.3 kg.day-1.animal-1 of supplement during two hundred seventy seven days. The methane was measured and collected in the last month before slaughter during three days at 6, 12 and 18 Hours using the laser methane detector (LMD). Daily weight gain (DWG), dry matter intake (DMI), emission factor (EF), grams of CH4 per kilograms of BW (CH4BW), grams of CH4 per kilograms of dry matter intake (CH4DMI), and net energy loss as CH4 (YM), were evaluated. Statistical analysis was carried out using GLIMMIX-SAS. A significant effect by treatment diet (P< 0.05) was observed on performance animal (DMI, DWG) and methane emissions (CH4gd, CH4DMI, CH4LWG, and YM); obtained the best response with BH+ENS, increased above-average DMI 11.37%; and DWG by 3.05%. CH4DMI decreased by 49.1% and CH4BW by 44.8%, representing lower energy losses by 57.2% with YM = 5.01%. ENS animals improves beef production and reduces methane emissions compared to traditional grazing system.