鸭肝炎病毒(DHV-1)及水飞蓟素对雏鸭生长的影响

 【目的】观察雏鸭接种亚致死量鸭肝炎病毒后生长速度的改变及水飞蓟素对其的影响。【方法】100只雏鸭分为8组，于10日龄接种病毒。第1、2、3组腿肌接种105倍稀释的病毒尿囊液，并分别口服0、30、50 mg?kg-1bw?d-1的水飞蓟素；第4、5、6组腿肌接种5×105倍稀病毒尿囊液并分别口服0、10、30 mg?kg-1bw?d-1的水飞蓟素；第7组为水飞蓟素对照组，不接种病毒，但口服水飞蓟素10 mg?kg-1bw?d-1；第8组为空白对照组，仅腿肌注射0.2 ml灭菌生理盐水。水飞蓟素连续给药5 d，于攻毒的第5天采集血浆，测定血浆T3、甲状腺素（T4）、IGF-Ⅰ浓度。于攻毒后10 d测定体重。【结果】用5×105倍稀释病毒尿囊液接种雏鸭，动物显示出显著高的生长速度（P＜0.01，与对照组比较），此种效应可被口服水飞蓟素剂量依赖性的抑制。T4水平在接种病毒后极显著的降低，未见水飞蓟素对其显著的影响，生长速度与血浆T3水平在一定程度上呈正相关关系，与IGF-Ⅰ水平相关性不强。【结论】 亚致死量鸭肝炎病毒可显著促进雏鸭的生长，水飞蓟素可拮抗病毒的这种作用，血浆T3水平与动物生长速度关系密切。

The Potential of Duck Hepatitis Virus(DHV-1)Stimulated the Body Weight Gain and the Effects of Silymarin on It in Younger Duck

Aim]To evaluate the effects of duck hepatitis virus-Ⅰ(DHV-Ⅰ) on the body weight gain in duck and the effects of Silybin on it in vivo.Methods] 86 10d old ducks,both male and female, were collected to be subjected to the test. The experiments were conducted in 7 groups: In geoup 1～3,the animals were inoculated with 1:105 diluted duck hepatitis virus infected allantoic fluids and given 0,30 and 50mg/kg.bw.d Silybin orally respectively. In group 4～6 ,the animals were inoculated with 1:5×105 diluted duck hepatitis virus infected allantoic fluids and given 0,10 and 30mg/kg.bw.d Silybin orally respectively.The group 7 was the control one treated by injecting stilled saline into the leg muscles. By the 4d after inoculation,the wein blood were drawed from the dorsal foot veins and the plasma samples were collectde and stored at -20℃ .The body weight gain were measured from 0 to 10 days after inoculation.The plasma IGF-Ⅰ,T3 and T4 consentrations were measured by RIA Results]At the virus dose of 1:5×105 diluted virus infected allantoic fluids,the inoculations of the virus enhanced the body weight gain significantly compared with that of control (P<0.01). While 10～50mg/kg.bw.d Silybinin could counteract the effects of the virus on the body weight gain dose-dependently.The plasma IGF-Ⅰlevels showed no correlative with the body weight gain,but the T3 levels showed a same tropism with the body weight gain. Conclution] Sublethal dose of duck hepatitis virus enhanced the body weight gain of younger ducks significantly,the Silybin could counteract this effect in vivo.