Evaluation of Methane Production Manipulated by Level of Intake in Growing Cattle and Corn Oil in Finishing Cattle

摘要

Crossbred steers (n=80; initial BW = 274 kg, SD = 21) were used to evaluate the effect of intake on CH4 and CO2 production in growing steers. Treatments included feeding the same diet at two levels: ad-libitum or limit-fed at 75% of ad libitum. This trial was followed by a finishing trial (n=80; initial BW = 369 kg; SD = 25) to evaluate the effects of adding dietary corn oil on CH4 and CO2 production. The corn oil treatment (OIL) displaced corn by adding 3% corn oil. Methane was collected in 2 pen-scale chambers (pens) by collecting air samples continuously. Steers fed ad-libitum gained more weight and ate more feed by design (P <0.01) compared to limit-fed cattle; however, efficiency offeed utilization was not different between treatments (P = 0.40). Cattle fed ad-libitum produced 156 g/d of CH4, which was greater (P < 0.01) than limit-fed cattle (126 g/steer daily). On an equivalent DMI basis, limit-fed steers tended to produce more CH4 (P = 0.07) than ad-libitum fed steers. In the finishing phase, body weight, gains, and carcass traits were not impacted by treatment (P > 0.14). Efficiency of feed use (P =0.03) improved because intakes (P = 0.03) decreased by feeding OIL compared to CON. Daily CH4 production was lower (P < 0.01) for the OIL fedcattle (115 g/steer daily) compared to the CON fed cattle (132 g/steer daily). Methane as a proportion of intake was lower (P < 0.02) for the OIL treatment compared to CON.