【作者】 李小杉；

【导师】 何宝祥；

【作者基本信息】 广西大学 ， 临床兽医学， 2011， 硕士

【摘要】 为了研究荷斯坦奶牛产前和泌乳早期血浆Leptin、血糖、血钙和血磷变化特征和规律、Leptin浓度对其他指标的影响,以及血浆钙在不同保存条件下的变化,本实验对30头2～4胎次的奶牛从产前1周到产后第9周,每隔7天颈静脉采血,分离血浆,测定血浆Leptin、葡萄糖、钙、磷的含量,并且测定5份奶牛血浆在室温、4℃和-20℃存放1天、2天、3天、5天、10天、20天、30天和50天时的血钙浓度。结果显示：(1)血浆Leptin在奶牛产后一周最低(2.24±0.14 ng/mL),从第3周开始逐渐升高,并于第6周达到峰值(18.81±4.64 ng/mL),之后逐渐下降,到第8周恢复至较低水平；分娩当天血糖浓度极显著高于其它时间(P<0.01)；泌乳第一周血钙最低,之后逐渐恢复,第6周达到最高；产前一周血磷浓度最低；(2)高浓度Leptin组奶牛(22头)在实验期间血浆Leptin浓度最高值均高于或等于32.8 ng/mL,低浓度Leptin组奶牛(8头)在实验期间血浆Leptin浓度均低于或等于6.8 ng/mL;在泌乳第6周高浓度Leptin组奶牛血浆Leptin浓度显著高于低浓度Leptin组奶牛(P<0.05)；(3)整体实验奶牛和高浓度Leptin组奶牛,血浆Leptin与血钙极显著正相关。(4)奶牛产后血浆Leptin浓度异常升高很有可能与血糖抑制有关。(5)在相同的保存条件下,血浆钙随着保存时间的延长逐渐下降；在相同的保存时间,血浆钙的保存温度越低,浓度下降的速度越慢。更多还原

【Abstract】 In order to study the variation characteristics and regularity of plasma leptin, glucose, calcium and phosphorus in prenatal and early lactation of Holstein cows, the effect of plasma leptin concentrations on other plasma indexes of Holstein cows, and the changes of plasma calcium in different storage conditions of Holstein cows. In this study, the author have been determined the concentrations of plasma leptin, glucose, calcium and phosphorus of 30 Holstein cows which in 2 to 4 parity and sampled every 7 days by jugular vein between one week before calving and 9 weeks postpartum. And determined 5 Holstein cows’plasma samples stored at room temperature,4℃and -20℃Storage 1 day,2 days,3 days,5 days,10 days,20 days,30 days and 50 days. The results shown that (ⅰ) the concentration of plasma leptin was lowest in the 1st week of postpartum (2.24±0.14 ng/mL), and began to increase at the 3rd week of lactation, peak at the 6th week (18.81±4.64 ng/mL), then gradually declined, and recovery to a lower level at the 8th week. The concentration of plasma glucose at the calving day was significantly higher than the other weeks (P<0.01). The lowest concentration of plasma calcium was at the first week of lactation, and then gradually recovered to normal, at the 6th week to reach the highest. The lowest concentration of plasma phosphorus was at one week before calving, (ⅱ) The higher leptin group (22) cows’maximum leptin concentrations during the experiment were higher than or equal to the value of 32.8 ng/mL, the lower leptin group (8) cows’leptin concentrations during the experiment were all lower than or equal to the value of 6.8 ng/mL. The concentration of plasma leptin in the higher leptin group was significantly higher than the lower leptin group at the 6th week of lactation (P< 0.05). (ⅲ) Overall experimental cows and the higher leptin group cows, plasma leptin were significantly correlated with plasma calcium. (ⅳ) it was probably that the abnormal increase of plasma Leptin concentration was relative to plasma glucose inhibition. (ⅴ) In the same conditions, the concentrations of plasma calcium are becoming lower with days past. And in the same time, the concentrations of plasma calcium are becoming lower with storage temperature increased.更多还原