Abstract

This experiment tested the hypothesis that methane emissions from dairy cows would be reduced, and milk production increased, when sodium fumarate was added to a diet of fresh pasture at a rate of 5% of dry matter (DM) intake. Sixteen ruminally fistulated dairy cows (100 ± 20.7 days in milk; 548 ± 47.8 kg liveweight; mean ± SD) received either a control (water) or fumarate treatment (10.3 ± 1.18 L/cow/day of solution providing 931 ± 126 g sodium fumarate/cow/day) over a 7-day adjustment period while grazing ryegrass pasture, followed by an 8-day experimental period fed pasture in metabolism stalls. During the experimental period cows on both treatments consumed 18.8 ± 1.83 kg DM/day, produced 1.81 ± 0.25 kg milksolids/day, and emitted 350 ± 44.9 g methane/day (5.9 ± 0.71% of gross energy). Total tract DM digestibility was high (78.8 ± 0.84%), and ruminal pH was 6.10 ± 0.15. Fumarate supplementation did not change ruminal fermentation, in vivo digestibility, methane emissions, milk production or composition, or selected plasma metabolites. The opportunity for reducing methane emissions from dairy cows by supplementing with fumarate or breeding high fumarate grasses may be limited for diets of high quality pasture. The limited reports of in vivo response to supplemental fumarate suggest that mitigation opportunities may be greater for pasture diets of low digestibility.

ES, Kolver, and PW Aspin

Proceedings of the New Zealand Society of Animal Production, Volume 66, Napier, 409-415, 2006