This study was aimed to determine the effects of hybrid and inoculant on in vitro rumen digestibility and rumen fermentation indices of corn silage. Two corn hybrids(Kwangpyeongok (KW) vs. Pioneer 1543(PI)) were ensiled for 100 days with two inoculants(L. plantarum(LP) vs. L. buchneri(LB)) applied at 1.2 × 105 cfu/g of fresh forage. Silages were incubated in rumen fluid medium at 39℃ for 72 hours. Both of KW and PI had no difference(p>0.05) on in vitro digestibility of dry matter(IVDMD) and neutral detergent fiber(IVNDFD), while application of LB produced higher(p<0.05) IVDMD and IVNDFD than LP. Hybrid and inoculant applications did not affect(p>0.05) total gas volume, ammonia-N, total VFA, and acetate concentrations in the rumen. Applied LB was higher(p<0.05) propionate concentration than LP, while hybrids had no effect(p>0.05). Furthermore, the interaction effect(p<0.05) was occurred in propionate concentration. Butyrate concentration did not affected(p>0.05) by hybrid and inoculant applications, but there was an interaction effect between hybrid and inoculant(p<0.05). Applications of hybrid and inoculant had effects(p<0.05) on iso-butyrate and valerate, without any interaction effects(p>0.05). This study concluded that application of KW and PI has no effects on in vitro rumen digestibility and rumen fermentation indices of corn silage, while application of LB increase the rumen digestibility in both of corn hybrids.

본 연구는 반추동물의 조사료 자원으로서 거대억새를 개발하기 위한 목적으로 수행되었다. 우리나라에서 새롭게 개발된 품종인 거대억새 1호를 완숙기 이후에 채취하여 in vitro 반추위 발효를 이용해반추위내 pH, 암모니아태 질소, 가스발생량, 휘발성 지방산 생성량 및 건물소화율을 조사하였으며,볏짚과 비교하여 평가하였다. 거대억새는 볏짚에 비하여 유의적으로 높은 반추위내 pH를 나타내었다(p<0.01). 암모니아태 질소의 경우 배양 12시간 이후에는 두 처리구간의 유의적인 차이를 나타내지 않았다 (p>0.05). 배양 6시간 이후 부터는 거대억새의 가스발생량이 볏짚에 비하여 유의적으로 낮게 나타났다 (p<0.05). 휘발성 지방산 생성량에 있어 acetate, propionate, butyrate, valerate 및 총생상량에서 볏짚이 거대억새보다 높게 나타났다. 그러나 iso-butyrate와 iso-valerate에서는 두 조사료원별 차이는 발견되지 않았다. 건물소화율에 있어 배양 12~24시간 사이의 거대억새 소화율이 볏짚에 비하여 유의적으로 나타났다. 결론적으로 거대억새의 이용성은 볏짚의 약 80% 수준인 것으로 나타났다.

We inoculated a spent mushroom substrate from Flammulina velutipes (SMSF) with a microbial additive and assessed the effects on chemical composition, ruminal fermentation parameters, and total-tract nutrient digestibility. In Exp. 1, three cannulated Hanwoo steers were used in an in situ trial to determine the degradation kinetics of dry matter (DM) and crude protein (CP). In Exp. 2, three Hanwoo steers were randomly assigned to experimental diets according to a 3 × 3 Latin square for a 3-week period (2 weeks for adaptation and 1 week for sample collection). Experimental diets included the control diet (3.75 kg/d formulated concentrate mixture + 1.25 kg/d rice straw), SMSF diet (3.19 kg/d formulated concentrate mixture + 1.25 kg/d rice straw + 0.56 kg/d SMSF), and inoculated SMSF (ISMSF) diet (3.19 kg/d formulated concentrate mixture + 1.25 kg/d rice straw + 0.56 kg/d ISMSF). The chemical composition of ISMSF did not differ from that of SMSF. Microbial additive inoculation decreased pH (P<0.05) and improved preservation for SMSF. The percentages of DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) in ISMSF were slightly lesser than those in SMSF. Ruminal fermentation characteristics and total-tract nutrient digestibility were not affected by diet. Overall, microbial additive inoculation improved preservation for SMSF and may allow improved digestion in the rumen; however, the total digestible nutrients (TDN) of SMSF and ISMSF diets were slightly lesser than the control diet. The ISMSF can be used as an alternative feedstuff to partially replace formulated concentrate feed.