Methane emission factors for beef cows in Argentina: effect of diet quality

ABSTRACT

To determine the methane (CH₄) emission factors for beef cows in Argentina, we carried out two experiments to test the effect of different diets on methane emission from grazing conditions. In experiment 1, diet consisted of native grass-based pasture vs. sorghum-based pasture (63.1% and 63.5% of dry matter digestibility (DMD) respectively), and in experiment 2, it consisted of native grass-based pasture vs. alfalfa hay (45.2% and 43.6% of DMD respectively). In both experiments, CH₄ production showed statistically significant differences (202.7 ± 11.5 and 157.5 ± 10.6 g/d for native grass-based pasture and sorghum respectively; 157.4 ± 8.9 and 190.6 ± 9.4 g/d for native grass-based pasture and lucerne hay respectively). The energy lost through eructation of CH₄ was less for cows grazing sorghum than for cows grazing native grass-based pasture (4.3% ± 0.3% vs 5.6% ± 0.4%), and it was similar between the latter and cows grazing alfalfa hay (7.1% ± 0.6% vs 8.2% ± 0.5%). The results support that low quality diets increase methane yield (Ym).

KEYWORDS:

• Enteric CH₄ emission
• SF₆ tracer technique
• grazing conditions
• diet quality
• beef cattle

Acknowledgement

The authors gratefully acknowledge the comments and inputs received from Dra. Laura Astigarraga. The authors also thank Dra. Gabriela Posse Beaulieu, Prof. Federico Boccacci and Prof. Karina Rullo for their valuable support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by National Agency for Scientific and Technological Research: [grant number PICT 2015-2530]; Instituto Nacional de Tecnología Agropecuaria: [grant number PNNAT 1128023]; Fondo Regional de Tecnología Agropecuaria: [grant number Project FTG/RF 1028RG]; Universidad Tecnológica Nacional: [grant number PID UTN MSUTNBA0004540].