1747
Methane production from dairy cows fed red clover- or corn silage-based diets supplemented with linseed oil

Tuesday, July 22, 2014
Exhibit Hall AB (Kansas City Convention Center)
Chaouki Benchaar , Agriculture and Agri-Food Canada, Dairy and Swine Research and Development Centre, Sherbrooke, QC, Canada
Fadi Hassanat , Agriculture and Agri-Food Canada, Dairy and Swine Research and Development Centre, Sherbrooke, QC, Canada
Rachel Gervais , Université Laval, Québec, QC, Canada
Roger Martineau , Agriculture and Agri-Food Canada, Dairy and Swine Research and Development Centre, Sherbrooke, QC, Canada
Abstract Text: The objective of this study was to examine the effect of linseed oil (LO) supplementation on enteric CH4 emissions from dairy cow fed red clover-(RC) or corn silage (CS)-based diets. Twelve lactating, multiparous Holstein cows (DIM = 91 ± 25; milk yield = 45.2 ± 4.7 kg) were used in a replicated 4 × 4 Latin square (35-d period; 14-d adaptation) with a 2 × 2 factorial arrangement of treatments. Cows were fed (ad libitum; 5% orts on an as-fed basis) a TMR (60:40, forage:concentrate ratio) not supplemented or supplemented with 4% LO (DM basis) and with the forage portion of the TMR consisting of either RC or CS. Production of CH4 was determined (3 consecutive days) using respiration chambers, while milk performance was determined over 6 consecutive days. Main effects of forage source, LO supplementation and interactions (LO × forage source) were determined using the MIXED Procedure of SAS and significance was declared at P ≤ 0.05. Significant interactions between LO and forage source were observed for DM intake, and yield of fat-corrected milk, which were not changed by adding LO to RC-based diets but decreased when LO was added in CS-based diets. Similarly, CH4 production (g/d or as a proportion of gross energy intake) was unaffected by supplementing LO to RC-based diets, but declined by 25% when LO was included in CS-based diets (LO × forage source interaction; P < 0.01). When expressed on FCM yield basis, CH4 production decreased with LO addition regardless the source of forage used (12.7 vs. 14.4 g CH4/kg FCM). Results of this study show that 4% LO had no effect on CH4 production when supplemented to RC-based diets, but decreased daily CH4 emissions and CHenergy losses if supplemented to CS-based diets.

Keywords: dairy cow, methane, corn silage, red clover silage, linseed oil