Study on the Utilization of Sawdust Bedding Barn for Dairy Cows II. Comparision of utilization efficiency of the different depth of sawdust bedding for dairy cows

착유우의 톱밥발효우사 이용 연구 제2보 :착유우 톱밥발효우사의 톱밥상 처리방법에 따른 이용효과 비교

This study was carried out to investigate the effect of depth of sawdust bedding and ground material in dairy cattle barn. Treatment included the concrete floor with a 10cm or 30cm sawdust and the earth floor with a 30cm sawdust. Eighteen cows were assigned to 3 pens with 16.5㎥/head bedding area. The results obtained were as follows : 1. The temperature of sawdust bed was highest in the earth floor with 30cm sawdust, and the moisture content of sawdust bed was highest in the concrete floor with 10cm sawdust bed. 2. Cows defecate feces 9.2, 8.7 and 9.3 times a day in 10cm sawdust on concrete floor(10S+C), 30cm sawdust on concrete floor(30S+C) and 30cm sawdust on non concrete floor(30S+ NC) respectively. In average, they excreta 9.1 times/day(85.8%) in the sawdust beds and 1.5 times/day(14.2%) in the feeding alley. 3. The ratio of daily water amount deposited vapor to total water amount deposited in sawdust beds was 74.0%, 61.5% and 47.1% in 10S+C, 30S+C and 30S+NC respectively. 4. N.P.K contents in the sawdust beds were higher for 10S+C compared with other treatments. 5. When 30cm of sawdust was applied on the earth ground NO$_3$-N contents in the sawdust bed was 37.7, 14.1 and 15.0ppm in depth of 30, 60 and 90cm under the ground, respectively, indicating some possibility of water pollution.

톱밥우사의 우상바닥처리 형태와 톱밥의 효율적 이용을 구명하기 위하여 PVC lightsheet지붕에 우상바닥처리별로 톱밥 10cm+콘크리트바닥, 톱밥 30cm+콘크리트바닥, 톱밥 30cm+바닥에 각각 경산우 6두(1두당 톱밥우상 16.5㎥)씩을 공시하여 시험한 결과 톱밥우상내 온도는 톱밥 30cm+흙바닥 처리가 가장 높았고, 수분증발량은 톱밥 10cm+콘크리트바닥에서 가장 많았다. 톱밥우사에서의 사료섭취 장소 및 톱밥우상의 분뇨배설은 단위면적당 톱밥우상에서는 91% 사료섭취장소에서는 9%가 배설되었으며, 착유우의 1일 분뇨 배설량은(착유시간 제외) 분 31.45kg, 뇨 10.7kg, 계 42.23kg이었으며 우분의 수분함량은 83.96%이었다. 공시완료한 분뇨가 혼합된 톱밥의 성분함량은 우분비율이 많은 톱밥 10cm+콘크리트바닥에서 무기물 성분이 가장 많이 함유되었으며, 흙바닥 처리구의 토양 중 NO$_3$-N함량이 허용한계 (10ppm이하)이상으로 검출되어 수질오염 가능성이 나타났다. 톱밥우상의 처리방법별 년간 유지비용은 톱밥 10cm+콘크리트바닥 처리가 년간 가장 적게 소요되었으며, 톱밥의 효율적 이용, 톱밥 교체시 노력절감 등으로 보아 가장 유리한 것으로 나타났다.