【作者】 熊双丽；

【导师】 张力； 郝正里； 郑中朝；

【作者基本信息】 甘肃农业大学 ， 动物营养与饲料科学， 2003， 硕士

【摘要】 将20头奶牛随机分为4组，一个对照组，A、B、C三个处理组，分别饲给四种不同阴阳离子水平(Dietary Cation-Anion Difference，DCAD)平衡值分别为+89.43、-53.75、-106.96、-150.07 meq／100kg DM的日粮，四种日粮其它各项主要营养指标(CP、ME、P)基本一致。测定不同阴阳离子水平对血清钙(Ca)、磷(P)、甲状旁腺素(PTH)、碱性磷酸酶(AKP)、降钙素(CT)及羟脯氨酸，饲粮钙磷的表观消化率，产乳量和乳中钙磷的变化及奶牛疾病发生情况的影响。试验结果表明：随着日粮阴阳离子水平(dietarycation-anion difference，DCAD)平衡值的降低，尿液pH值降低，血清钙、降钙素、碱性磷酸酶、羟脯氨酸含量升高。处理组奶牛血清钙总平均值含量都极显著高于对照组(P＜0.01)，A组、B组和C组分别比对照组升高了47％、71％和48％，对照组比正常值降低了27％-56％(正常值一般为1.80-3.00mmol／l)，处于亚临床低血钙状态，曲线波动变化明显，产后血清钙突然明显降低，B组奶牛血清钙总平均值含量极显著高于其它各组(P＜0.01)，分别比对照组、A组和C组升高了71％、17％和15％，并且产前产后曲线变化幅度小，血清钙含量变化不明显，此组DCAD平衡值最佳。A组和C组平均值含量差异不显著(P＞0.05)。各组奶牛血清磷水平接近，均处于正常水平(正常值一般为1.06-3.09mmol／l)，并且都在产后第1天降至最低，随后开始升高。对照组血清甲状旁腺素总平均值含量最高，分别比A组、B组和C组升高了220％、22％和236％，但其血钙总平均值含量水平仍然最低，分别比A组、B组和C组降低了32％、42％和33％，与B组差异不显著(P＞0.05)，两组都极显著高于其它两组(P＜0.01)，A组与C组差异不显著(P＞0.05)。对照组奶牛血清降钙素总平均值含量最低，分别比A组、组B和C组降低了8％、36％和39％，其次为A组，两者差异不显著(P＞0.05)，但两者都极显著低于B组和C组(P＜0.01)。C组AKP总平均值含量最高，极显著高于对照组和A组(P＜0.01)，与B组差异不显著(P＞0.05)，A组极显著低于其它组(P＜0.01)。B组奶牛血清羟脯氨酸和钙呈显著负相关(r=-0.76，P＜0.01)，并且其平均值含量极显著高于其它各组(P＜0.01)，其它组两者之间皆呈不显著相关，而C组平均值含量又显著高于其它两组(P＜0.05)，对照组血清羟脯氨酸总平均值含量最低，分别比A组、B组和C组降低了7％、77％和32％。处理组饲料钙、磷表观消化率、产奶量均升高，但差异不显著(P＞0.05)。乳钙、磷及粗蛋白含量变化不大。对照组胎衣滞留率为20％，处理组胎衣滞留率7％，胎衣滞留率降低了65％。更多还原

【Abstract】 Twenty Holsteins were blocked and assigned randomly to treatments of +89.43, -53.75, -106.96, -150.07meq[（Na++K+）-(Cl^-+S^2-)]/Kg of DM dietary.The first was control group,the others were treatment groups.The other main nutrient index （CP, P, ME） almost had no difference among diets.The objective of this study was to examine the inflence of dietary cation-anion differnce （DCAD） on serum Ca, P, PTH, CT and oxyptoline concentration, the apparent digestibility of Ca and P , the variation of Ca and in milk and the ocurrence of disease.The results indicated that the serum Ca, CT, AKP and oxyptoline concentrations increased and pH in urine declined with DCAD decreasing.The total average Ca concentrations in treatment groups were significantly higher than that of control group（p<0.01）.In group A, B and C,it promoted by 47%, 71%and 48% than that of control group respectively.But in control group it declined by 27%-56% than normal value and the cows were in subclinical hypocalcaemia condition all along（normal value is generally 1.80-3.10mmol/l）.The curve of it fluctuated markedly and parturient serum Ca concentration decreased dramanticaly.The total average Ca concentration in group B improved by 71%, 17% and 15% than that of contol group, group A and B respectively,It was exetremly higher than those in the other groups（p<0.01） and the curve of it was equable pre-and-post calving,the DCAD was optimum. The total average Ca concentration had no significant difference between group A and C（p>0.05）.The sernm P concentrations were not affected by supplementing the diet of dry cows with anionic additive,which maitained normal（normal value is generally 1.06-3.09mmol/l）,and it decreased to the lowest on the first day precalving and later gradually increased. The total PTH average concentration in control group was the highest, which had no significant difference with group B （p>0.05） and increased by 220%, 22% and 236% than that of group A, B and Crespectively,both of them were exetremely higher than those of the other two groups（p<0.01）.The total PTH average concentration had no significant difference between group A and C（p>0.05）.But the total average Ca concentration in control group was the lowest, which declined 32% 42% and 33% than that of group A B and C respectively.The total CT average concentration in control group was the lowest, which had no significant difference with group A （p>0.05） and declined 8% 36% and 39% than group A B and C respectively,But they both were much lower than those of the other two groups（p<0.01）.The total average AKP concentration in group C was the highest , which was exetremely higher than those of control group and group A （p<0.01）,and had no significant difference with group B. The total average AKP concentration in group A was significantly lower than that of the others. The oxyptoline concentrations in all groups were in negatively correlation to Ca.The total average oxyptoline concentration in B group was the highest, which was in siginificantly correlation to Ca（p<0. 01）. Control group was the lowest.which declined by 7% 77% and 32% than that of group A, B and C respectively. In treatment groups the apparent digestibility of Ca and P the average yield of milk also increased with DCAD decreasing. But the Ca and P concentrations in the milk were unaffected by adding anionic additive to the diet. The incidence of retained Placenta in control group and treatment groups were 20% and 7% respectively,the former declined by 65% than the latter.更多还原