κ-CN 및 β-LG 유전적 변이체의 phenotype이 다른 집합유의 Cheddar 치즈 생산수율

Abstract

This study was conducted to understand on the effect of the phenotypes of κ-CN and β-LG genetic variants of cows on Cheddar cheese yield. Among 50 Holstein cows raised at the experimental farm of Yonam College, 15 cows were selected and divided them into two groups based on the routine milk quality managing system. The phenotypes of κ-CN and β-LG were analyzed by PCR-RFLP and curd production yields (37% moisture content corrected yield) of each cow were compared. β-LG phenotypes AB (12.77% and 15.26%) showed higher curd production than β-LG phenotypes AA (10.67% and 10.86%) or BB type (10.11%). As a result, the curd production yields of Group-1 with a C/F ratio of 0.63 and Group-2 with that of 0.72 were 11.95% (theoretical yield of 11.88%) and 9.69% (theoretical yield 9.86%), respectively. The cheese yield of Group-1 was high about 2.26% (theoretical yiel 1.92%) despite of the lower than Group-2 in C/F raio. In fact, the weight of cheddar cheese made with 100 L of Group-1 bulk milk was 12.8 kg and the yield of cheese was 11.93% (theoretical yield of 11.67%). This study suggests that it is possible to secure price competitiveness in the domestic market by improving the cheese production yield and by supplying dairy cows with high production yield genes to cheese-making farms through molecular breeding studies of cows.