172 Enteric methane emissions from pregnant beef heifers as affected by multiple mitigation strategies. (30th November 2020)

• Record Type: Journal Article
• Authors: Teranishi, Rhea E; McGeough, E J; Wittenberg, Karin; Crow, Gary; Ominski, Kim
• Is Part Of: Journal of animal science. Volume 98(2020)Supplement 4
• Page Start: 131
• Page End: 131
• Publication Date: 2020-11-30
• Subjects: Beef cattle -- enteric methane -- stacking; Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.1093/jas/skaa278.240
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: This study was conducted to determine if enteric methane (CH4) emissions from pregnant beef heifers could be reduced by using multiple dietary mitigation strategies. The trial was designed as a 4 x 4 Latin square consisting of a 21-d adaptation phase followed by a 21-d data collection phase. Forty Aberdeen Angus cross pregnant beef heifers were randomly assigned to one of the four dietary treatments (n = 10): i) low protein grass hay (L; 6.1% CP; 1.9% fat); ii) adequate protein grass hay (AD; 10.8% CP; 1.9% fat); iii) AD supplemented with sunflower screenings (ADSS; 9.8% CP; 5.6% fat); and iv) above adequate protein legume grass mix hay (AAD; 12.8% CP; 1.7% fat). Total dry matter intake (DMI) was 32%, 27% and 39% greater (P < 0.0001) for AD, ADSS and AAD respectively, relative to the L diet (6.5 kg d-1). Average daily gain (ADG; kg d-1) was influenced by dietary treatment (P < 0.0001), as heifers offered L, AD, ADSS and AAD diets gained 0 ± 0.2, 0.6 ± 0.2, 0.5 ± 0.2 and 0.7 ± 0.2 kg d-1, respectively. Enteric CH4 emissions (L d-1), were influenced by dietary treatment (P < 0.0001) with 184 ± 18.9, 214 ± 19.0, 204 ± 19.1 and 232 ± 19.1 L d-1 for heifers offered L, AD, ADSS and AAD diets, respectively. Further, heifers offered AD, ADSS and AAD diets emitted 19%, 22% and 14% less (P=0.03) enteric CH4 (% GEI) relative to diet L, respectively. This study demonstrates that supplementation to meet nutrient requirements for protein or increasing the fat content of forage-based diets using low-cost by-products such as sunflower screenings can decrease enteric CH4 emissions without adversely impacting total DMI and ADG.