Impact of Napier Grass on Dairy Cow Lactation and Methane Emissions
A recent experiment examined the impact of replacing natural pasture hay with Napier grass hay on feed intake, milk yield, and methane emissions in lactating dairy cows. Conducted with five crossbred dairy cows under a 5×5 Latin square design, the study tested diets ranging from 100% natural pasture hay to 100% Napier grass hay, with intermediate combinations.
Results indicated that increasing the proportion of Napier grass hay significantly enhanced dietary crude protein content and improved dry matter and nutrient intake. Specifically, milk yield rose from 11.4 liters per day with 100% natural pasture hay to 16.1 liters per day with 100% Napier grass hay. Additionally, milk protein yield increased, and feed efficiency improved.
Moreover, the estimated enteric methane emission intensity decreased as the inclusion of Napier grass increased. Methane emissions dropped from 26.9 g/kg of milk yield with 100% natural pasture hay to 20.6 g/kg with full Napier grass substitution.
The study's authors suggest that replacing natural pasture hay with Napier grass hay could serve as a climate-smart feeding strategy for smallholder dairy systems in Ethiopia. This finding is particularly relevant for enhancing lactation performance while addressing environmental concerns related to methane emissions.
The experiment was supported by Injibara University, which provided resources for forage cultivation and necessary materials. The study was published in Scientific Reports on June 8, 2026.
