CSAS Oral Student Competition: MS Session
This study investigated the effects of adding sunflower screenings, flax screenings and quinoa to a hay-based diet on ruminal fermentation, DM digestibility (DMD) and enteric methane (CH4) production in an artificial rumen system (RUSITEC). The experiment was a RCBD with 4 treatments assigned to 16 fermentation vessels (n=4/treatment) in 2 RUSITEC apparatuses. The control diet was 100% hay, with treatments consisting of sunflower screenings, flax screenings and quinoa dockage at inclusion rates of 1.10, 1.38, and 1.59 g DM, respectively. The study period was 15 d, with an 8-d adaptation and 7-d sample collection period. Data were analyzed using the PROC MIXED procedure of SAS with fixed effects of treatment, day of sampling and their interaction as fixed effects. Compared to control, the addition of sunflower screenings decreased (P=0.020) CH4produced per g of DM digested (10.43 vs. 7.88 mg/g DMD). Inclusion of sunflower screenings reduced (P< 0.01) DMD (67.6 vs. 57.8 %) and the number of protozoa (2.2x104vs. 1x103ml) compared to the control. The addition of flax screenings versus the control diet increased (P=0.001) CH4produced per g of DMD (10.43 vs. 15.05 mg/g). However, inclusion of flax screenings resulted in a decrease (P< 0.05) in DMD and number of protozoa compared to the control (1.07x103vs. 2.2x104ml, 64.33 vs. 67.64 %, respectively). The addition of flax screenings decreased DMD (P=0.04). Quinoa inclusion had no effect on DMD or protozoa count, while CH4production increased (P=0.0003) compared to the control (15.15 vs 10.43 mg/g DMD). Disappearance of NDF did not differ between treatments (P=0.72). Inclusion of sunflower screenings and quinoa did not affect molar proportions of propionate or and butyrate, while decreased (P< 0.05) by adding flax screenings. In conclusion, the addition of sunflower screenings provided the greatest potential to reduce CH4emissions associated with supplemented hay-based diets.