Interpretive Summary: Substituting ryegrass-based pasture with graded levels of forage rape in the diet of lambs decreases methane emissions and increases propionate, succinate, and primary alcohols in the rumen
By: Maria M Della Rosa, Edgar Sandoval, Peter Reid, Dongwen Luo, David Pacheco, Peter H Janssen, Arjan Jonker
The methane yield (g methane/kg dry matter intake) was 34% lower in sheep fed 100% forage rape and 11% lower in sheep fed 75% forage rape compared to sheep fed 100% ryegrass-based pasture. Sheep fed 25% and 50% forage rape as part of their diet had similar methane yields to sheep fed 100% ryegrass pasture. Sheep fed 100% forage rape had a ruminal fermentation profile with a smaller proportion of acetate and greater proportions of fermentation products like propionate, succinate, and valerate. Acetate formation is associated with hydrogen gas formation, which in turn is converted to methane in the rumen. Propionate, succinate, and valerate are alternatives to acetate plus hydrogen production and so fermentation shifts to them result in less methane formation.
Read the full article in the Journal of Animal Science.