Estimation of methane emissions by dairy cows feeding on diets based on Italian ryegrass or legume silages in two grazing seasons

Bijeenkomst: EGF2015
Auteur: Dachraoui M., Jiménez-Calderón J.D., Martínez-Fernández A. and Vicente F.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
The dairy sector plays an important role in the emission of greenhouse gases (GHG). Dairy cows are a significant contributor to total livestock GHG emissions, being the main sources carbon loss from land use change, methane emissions from enteric fermentation, soil nitrous oxide emissions and manure management. For this reason, the objective of this study was to estimate methane emissions using the IPCC model in lactating Holstein cows with feeding rations based on Italian ryegrass silage grown conventionally or fava bean-rapeseed silage fertilized with manure and slurry in two grazing seasons, and to compare the results obtained with other models tested. Two trials were carried out in spring and autumn 2013, each with ten lactating Holstein cows. Both trials were performed using a crossover design. Considering the IPCC Tier 2 as an international reference to estimate enteric methane emissions, the estimations were similar considering both seasons and diets. When the IPCC predictions were compared to other models, the results showed the same variation of methane production, but with higher values for Mills and Yates models and lower estimations based on Ellis equations.