Ruminal methane emission by Boer and Spanish does supplemented with garlic

Twenty Boer (B; 2-7 yr of age and 48.5 ± 2.2 kg) and 20 Spanish (S; 4-6 yr of age and 39.3 ± 1.5 kg) does were used to examine effects of garlic on ruminal methane emission and heat production. Ten does of each breed were randomly allocated to control (C) and garlic (G) treatments. All does received 200 g/d (as-fed basis) of a concentrate mixture consisting of 54.4% ground corn, 26.0% soybean meal, 12.9% molasses, and 6.7% mineral and vitamin sources. The G does also received 20 g/d (as-fed basis) of garlic powder. For at least 2 mo does grazed grass/forb pastures in the summer. Thereafter, sets of 4 does consisting of 1 doe per treatment (CB, CS, GB, and GW) were sequentially placed in metabolism crates for 2 wk, continued to receive supplements, and were fed coarsely ground alfalfa hay free-choice. Gas exchange was measured on the last day for 24 h in an indirect, open circuit respiration calorimetry system with 4 metabolism cages fitted with head-boxes. There were no interactions between breed and supplement treatment (P > 0.05). Alfalfa hay DMI during the calorimetry measurement period was greater (P 0.05) respiratory quotient (1.012, 1.004, 1.003, and 0.994), heart rate (73, 72, 72, and 70; SEM = 1.6), heat production (450, 444, 447, and 432 kJ/kg BW0.75; SEM = 10.7), or the ratio of heat production:heart rate (6.18, 6.19, 6.18, and 6.21 kJ/kg BW0.75 per heart beat for CB, CS, GB, and GS, respectively; SEM = 0.056). In conclusion, supplementation with garlic decreased ruminal methane emission and increased DMI by Boer and Spanish does consuming alfalfa hay.