제주지역 Holstein 유우의 산유능력과 원유의 품질에 관한 연구 1 . 원유의 계절적 성분변화와 세균학적 품질 = A Study on the Milk Yield and Raw Milk Quality of the Holstein Cows in Cheju - Do Area 1 . Seasonal variation in composition and bacteriological quality of raw milk

다국어 초록 (Multilingual Abstract)

Seasonal changes of milk components, proportion of rejected milk, bacterial counts and the relationship between milk fat and solid-not-fat (SNF) of farm milk were studied over a period of two years(1987-1988). The results obtained were as follows: 1. Mean values of milk fat, protein, lactose, SNF and total solid were 3.72, 3.19, 4.60, 8.68, and 12.40 % respectively. 2. A significant correlation coefficient exsisted between milk fat and SNF content (P$lt;0.01). The coefficient and regression equation in the first and second year were r=0.347, Y=7.637+0.2777X and r=0.292, Y=7.715 +0.254X respectively. 3. The incidence of rejected milk was 0.75% of total quantity of raw milk recieved. It was higher rejected milk percentage than other region of the mainland and was affected greatly by season. 4. Coli-form bacterial count of the raw milk samples showed 46.3%m were under 100,000 cfu/ml and 53.7% were over 100,000 cfu/ml. 5. More than 4 x 10^7 cfu/ml live bacteria were counted in the raw milk with 53.8 % of the farm surveyed.