초록
전라북도 고창 조사 지역 내 유기 낙농 농가 수는 연도가 지남에 따라 증가하지 않았지만, 전체적인 사육규모와 사육두수는 증가하였다. 연 평균 유량은 국내 검정 농가 평균에 비해 유기 낙농가가 최대 9 kg/d가 낮았지만 유지방과 유단백 함량에서는 큰 차이를 보이지 않았다. NRC (2001)의 사양표준 프로그램을 이용하여 영양소 공급 수준을 평가한 결과, 급여 사료의 에너지 비율 특히 비구조탄수화물의 비율을 감소시킬 필요가 있으며, 또한 대사단백질 및 섬유소 비율을 증가시켜 전체적인 영양소 공급 수준을 조정한다면 착유우의 건강상태 및 유생산성이 개선될 것으로 생각된다.
This study was conducted to evaluate the milk productivity and nutrient balance in organic dairy farms located at Gochang-gun of Korea with different feed sources. The total number of organic dairy farms was 12 in 2012, 13 in 2013, and 14 in 2014. The numbers of farms and dairy herds were increased each year. The average milk yields in 2012, 2013, and 2014 were 25.5, 24.6, and 24.4 kg/d, respectively. The average milk fat contents in 2012, 2013, and 2014 were 3.5%, 3.6%, and 3.7%, respectively. The average milk protein contents in 2012, 2013, and 2014 were 3.3%, 3.4%, and 3.4% in 2012, 2013, and 2014, respectively. Although the average milk yield of organic dairy farms was 9 kg/cows/d less than the average milk yield of other dairy farms in Korea, milk fat and protein contents of organic dairy farms were higher than those of other dairy farms. Alfalfa hay, oat hay, corn silage, rye grass silage, Sudan grass silage, rice straw, and barley silage were commonly used as forage sources in organic dairy farms. The average silage intake (15.6 kg/cow/d) of organic dairy farms in 2013 was higher (P < 0.05), while the average hay intake (5.1 kg/cow/d) in 2014 was higher (P < 0.05) than that of other feed intake. Net energy for lactation ($NE_L$) and metabolizable protein (MP) were calculated in accordance with NRC (2001). Net energy for lactation intake was higher (P < 0.05) while MP intake was lower (P < 0.05) than NRC recommendation values in 2013 and 2014. These results indicate that domestic organic dairy farms should use feed considering energy and protein balance recommended by NRC.