Abstract #T263

# T263
Faba bean (Vicia faba L. major) inclusion in dairy cow diets: Effect on enteric methane production and milk performance.
C. Cherif*1, F. Hassanat1, S. Claveau1, J. Girard2, R. Gervais2, C. Benchaar3, 1Agriculture and Agri-Food Canada, Sherbrooke Research and Development Centre, Sherbrooke, QC, Canada, 2Agrinova, Alma, QC, Canada, 3Département des Sciences Animales, Université Laval, Québec, QC, Canada.

The objective of this study was to determine the effect of including fava bean in dairy cow diets on intake, milk production and enteric CH4 emissions. Nine lactating cows (DIM = 121 ± 28; milk yield = 41.2 ± 5.6 kg) were used in a replicated 3 × 3 Latin square (38-d period; 14-d adaptation). Cows were fed (ad libitum) a TMR composed (on DM basis) of 58.5% forages (20% corn silage; 35% alfalfa silage; 3.5% timothy hay) and 41.5% concentrates. In the concentrate portion, soybean meal and ground corn grain (Control) were completely and partially replaced, respectively, with either rolled (RFB) or ground (GFB) fava bean (17% DM). Diets were isonitrogenous (16% CP) and isoenergetic (NEL = 1.50 Mcal/kg). Intake, digestibility and milk performance were determined over 6 consecutive days while CH4 was measured using respiration chambers (5 consecutive days). Data were analyzed using the MIXED procedure (SAS) and differences between treatments and the control were declared significant (P ≤ 0.05) using Dunnett’s comparison test. Intake (25.7 kg/d) and digestibility (68.8%) of DM were not affected (P > 0.50) by the inclusion of GFB or RFB in the diet. Compared with the control, yield of ECM was not affected when cows were fed RFB (39.2 and 38.5 kg/d, respectively; P = 0.34), but declined when cows were fed GFB (37.7 kg/d; P = 0.02). Enteric CH4 production averaged 539 g/d and was not affected by dietary treatments (P = 0.74). Methane emissions expressed as g/kg DMI, % of gross energy intake or g/kg of ECM were not affected by dietary treatments and averaged 20.9 g/kg (P = 0.14), 6.3% (P = 0.14) and 14.0 g/kg (P = 0.46), respectively. Results from this study show that replacing soybean meal and ground corn by 17% of RFB or GFB on isonitrogenous and isoenergetic basis had no effect on enteric CH4 emission. Milk production (ECM) was not changed by feeding RFB but decreased when cows were fed GFB, compared with the control diet. In conclusion, if provided rolled rather than ground in dairy cow diets, fava bean has no adverse effects on enteric CH4 emission and milk performance.

Key Words: fava bean, enteric methane, milk production