유우군능력검정(乳牛群能力檢定)(2) = Dairy herd performance test(2)

다국어 초록 (Multilingual Abstract)

As same last year, the systematic performance test from October, 1979 to December, 1980 was made on the 5,119 heads of multipara dairy cattle distributed in 268 dairy farms over the five couties of Yangju , Pyongtaek, Cheonan, Naju and Yangsan.
Undertanding the individual ability of dairy cattle, we were to provide the scientific data for the improvement of dairy farm management. In addition we were planned to sort out and grade the objectives according to their ability. which meant to preserve the superiorities while others to be weeded.
The results of survey and analysis can be abstracted as followings :
A. Age, Calving, Breeding season.
The tested cattles of December were 3,780 heads. 79.7% of them was 3,010 heads aged below 6 years. 86.5% of the tested were 3,270 heads , which experienced calving four times at most. As of December calving in 12 months was 82.0% , in 18 months 96.6 % . Calving rate of summer and autumn was higher.
B. Ratio of milking cow.
Ratio of milking cow about multipara cow was average 81.7%.
C. Rationed feed.
Average daily quantity of concentrated feedstuff supplied per head was 8.4 kgs and a little bit higher to Yangju area than other areas.
D. Ratio of milk production of feed.
The average ratio was 25.7%. Especially, the rate of Yangju marked higher.
E. Feed effect.
Average feed effect was 1.9. May, June of year and Pyongtaek marked higher.
F. Milk production.
Daily milk production available per head was average 15.7 kgs. The average quantity Cheonan, Naju was lower and April, May, June was higher.
G. Milk fat percentage.
Average milk fat percentage was 3.63% . It was low in June, July and August and high in January and December, Yangju showed low.
H. Results of 305 days test.
Milk production : 4,957 kgs
Milk fat percentage : 3.7 %
Milk fat : 181 kgs
Supplied concentrate : 2.348 kgs
Ratio of milk production of feed : 25 %
Feed effect : 2.1
Ability index of body weight : 10