Abstract
cows, in order to suggest a means for the improvement of milk production. A total of 30 Holstein cows (3rd to 5th of parity) were used and assigned to two groups according This study investigated blood biochemical values between high and low yielding dairy to milk production levels at 15, 30, 60 and 90 days postpartum. Milk production of group A was less than an average of 27 kg/day and that of group B was an average of 30 kg/day. Blood samples were collected by jugular venipuncture from each cow six times at 15 days before the anticipated calving date, within 12 hours postpartum (0 days) and at 15, 30, 60 and 90 days after calving. In serum mineral concentrations, group B was consistently higher than group A in both Mg and Ca. Inorganic phosphorus concentrations showed a little fluctuation between the groups at antepartum and at postpartum, but group B was significantly higher than group A at 15 and 30 days after calving (p < 0.05). In serum biochemical values cholesterol concentrations were consistently higher in group B except at 0 days. BUN and glucose concentrations did not differ between the groups. The concentration of vitamin A of group B was significantly higher than group A at 15 days before the anticipated calving date and at 15 days postpartum (p < 0.01), but at 30, 60 and 90 days postpartum vitamin A concentration of both groups were similar. Vitamin E concentration did not differ between the groups during the experimental period. Results of this study suggest that raising the levels of Mg, Ca, Pi and vitamin A in serum would be effective in increasing milk production of low producing cows.
젖소에서 우유생산량의 증가시키기 위한 방안을 제시하기 위하여, 고능력우와 저능력우의 혈액화학치를 조사 연구하였다. 젖소 30두(3산에서 5산 사이)를 분만후 15, 30, 60, 90일의 착유량을 기준으로 두 군으로 나누었다. 착유량이 27 kg/day 이하인 군을 A(group A)군으로 하고, 30 kg/day 이상인 군을 B(group B)군으로 하였다. 혈액 샘플은 경정맥을 통하여, 분만전 15일, 분만후 12시간 이내(0 days), 분만후 15, 30, 60, 90일에 채혈하였다. 혈액 광물질 중 Mg과 Cg 농도는 B군이 A군보다 지속적으로 높았다. 무기인 농도는 두 군간에 분만전후에 변동이 있었으나, 분만후 15일과 30일에는 B군이 A군보다 유의성있게 높았다 (p<0.05). 혈액화학치 중에 cholesterol 농도는 분만당일을 제외하고는 B군이 지속적으로 높았고, BUN 농도와 glucose 농도는 두 군간에 차이가 없었다. 비타민 A 농도는 분만전 15일과 분만후 15일에 B군이 A군보다 유의성있게 높았고 (p<0.01), 비타민 E 농도는 실험기간동안에 두 군 사이에 차이가 없었다. 결과적으로 우유 생산량을 증가시키기 위해서 저능력우에 분만 전후에 사료 중에 Mg, Ca, Pi 과 비타민 A를 첨가하여주는 것이 효과가 있을 것이다.
