Effects of different barely/common vetch diets on nutrient digestibility and greenhouse gas emission of sheep

Here we evaluate the effects of different proportions of common vetch (Vicia sativa) diets on the digestibility and metabolism as well as greenhouse gas emission of sheep. Twelve 6-month-old hybrid rams weighing 30 ± 1 kg were chosen and randomly assigned into two groups. The animals from the two groups were fed with different diets supplemented with different proportions of common vetch. Dietary barely∶common vetch was in the ratio of 8∶2 or 6∶4. The pre-test period lasted for 15 days, and the trial period lasted for 9 days, after which the sheep were transferred to metabolic cages for digestion and metabolism trial using total urine and fecal collection method. The result revealed no significant differences in dry matter intake and nutrient digestibility between the two groups (P < 0.05). The daily O₂ consumption per kilogram body weight BW^0.75 in the 6∶4 group tended to be higher than that in the 8∶2 group (P = 0.083). No significant difference in CH₄ and CO₂ daily emission was observed between the two groups (P < 0.05). Thus, the feeding effect of 20% common vetch and 40% common vetch on nutrients digestion and greenhouse gas emission of sheep was similar.