128 Cherry Valley ducks in good health of 1 day old were divided into 4 groups:control group,soybean isoflavone at 5 mg/kg,soybean isoflavone at 10 mg/kg,and soybean isoflavone at 15(mg/kg),each group had 4 repetitions and 8 ducks in each treatment(4 female,4 male),and then slaughtered at 21 and 42 days to test the Ca,P,Ca/P,both in blood and bone.The results showed that the content of calcium and phosphorus had no significant difference among groups(P0.05) except to the group at(5 mg/kg).The content of calcium and Ca/P were decreased(P0.05)) in blood of the female duck and the content of calcium in group at(5 mg/kg) was less than the group at 15 mg/kg in male duck before three weeks.No significant difference was found among other groups(P0.05).The content of Ca,P and Ca/P in thighbone and cannon born had no significant difference(P0.05)before three weeks.After three weeks,the wet weight of thighbone of group at(15 mg/kg) in female duck was higher than control group and the group at 10 mg/kg.Ca/P was higher than the group at 5 mg/kg(P0.05).To male duck,the content of minerals was higher in the group at 5 mg/kg than others.The content of P in cannon bone of male duck of control group was higher than the groups at 5 and 10 mg/kg(P0.05),the difference was not significant among the other groups(P0.05).It suggested that soybean isoflavone can adjust the activity of calcium and phosphorus metabolism in Cherry Valley duck;lower dose prevent the formation of bone and higher dose prevent the happen of bone loss on the older duck.

自从1992年秸秆养牛示范工程正式列入国家农业综合开发项目以来,目前已在全国范围内初步形成了中原、东北和华南三大肉牛带.1996年全国牛肉产量494.9万t,是项目开发前1991年的3.2倍,年递增率为26.61%.目前适度规模化的肉牛饲养已成为农业经济的支柱产业.规模化肉牛饲养管理技术是牛的科学选购、饲养管理、饲料加工等各项技术的综合运用.