친환경 흑염소 사양을 위한 최적 조사료 초종 및 TMR 혼합비 비율: In vitro 반추위 발효 연구

This study was conducted to investigate the effects of TMR on in vitro rumen fermentation and methane production of goat with different forage sources. The experiment was arranged 4×2 factorial design. The different forage sources were rice straw (RS), Italian rye grass (IR), timothy (TI) and alfalfa (AL), respectively. There were two different forage : concentrate ratios such as 20:80 (20) and 50:50 (50), respectively. Therefore, totally 8 treatments were used: 1) RS20, 2) RS50, 3) IR20, 4) IR50, 5) TI20, 6) TI50, 7) AL20, and 8) AL50, respectively. The rumen fluid of goat was collected from the slaughterhouse. For fermentation parameters, ruminal pH, total gas, methane, hydrogen, ammonia nitrogen, and volatile fatty acid were determined. The pH values were within an optimal range across all treatments. Total gas productions at TI20 and AL50 were significantly greater than others (p<0.05). Methane production was significantly lower in TI and AL compared with other treatments (p<0.05). The relatively high dietary NDF content in treatments showed significantly lower methane production (p<0.05). Significant alterations treatments were detected at ammonia nitrogen concentration according to the ratio of forage : concentrate (p<0.05). AL treatment showed greater total volatile fatty acid production compared with other treatments (p<0.05). Therefore, the present study suggests that both Timothy and Alfalfa could be recommendable forage sources for goat based on results with volatile fatty acid as an energy source and methane as an index for energy loss and environmental issues. Also, the 50:50 (forage : concentrate) ratio would prefer to 20:80.