Enteric methane emission estimates for the Zimbabwean Sanga cattle breeds of Tuli and Mashona

Abstract

The effectiveness of methane mitigation in ruminant livestock production systems depends on the accuracy of estimating methane emission factors and providing accurate emission inventories. Following the Paris Climate agreement, it is recommended that countries adopt the Tier-2 approach for estimating enteric methane emissions from ruminants instead of the Tier-1 approach currently used by most countries. This study sought to provide base line enteric methane emission estimates for the Tuli and Mashona Sanga cattle breeds in Zimbabwe using the IPCC Tier-2 model. Using animal characterization data collected from 412 cattle from Grasslands Research Institute and 406 cattle from Makoholi Research Institute, net energy requirements were estimated. From this and the estimate for digestibility, gross energy intake and dry matter intake were estimated. Gross energy intakes and the estimated methane conversion factor were used to estimate enteric methane emissions. Mean emission factors for Tuli were 45.1, 56, 28.5, 28.4, 20.6kg CH 4 /head/year for cows, bulls, heifers, steers and calves respectively. For Mashona, they were 47.8, 51.9, 29, 29.1 and 20.7kgCH 4 /head/year for cows, bulls, heifers, steers and calves respectively. Generally, estimated Tier-2 emission factors were significantly different from the IPCC Tier-1 default emission factors. This study concluded that enteric methane emission factors estimated using the IPCC Tier-2 model offer insights into the controversial use of the default IPCC Tier-1 emission factors.

Substituting effects of winged bean tuber-modified starches for cassava chip in concentrate diets on rumen fermentation, nutrient utilization, and blood metabolites in Thai native beef cattle

“…This occurs due to the hydrolysis or melting of some cellulose and hemicellulose components on the surface when materials are exposed to high temperatures [23]. Consequently, this process has the potential to alter and increase the specific surface area of the feedstuff, thereby enhancing feed utilization and digestibility [21,22,24]. Yahaghi et al [25] demonstrated that replacing barley with steam-treated sorghum grain in lamb diets could lead to improved ruminal fermentation and fiber digestibility.…”