饲喂不同水平外源孕酮提高水貂繁殖性能的研究

Investigation on feeding exogenous progesterone on reproductive performance in the mink

为了探讨外源孕酮(P_4)对水貂繁殖性能的作用,选择最佳的P_4添加量,随机选择3月7日初配,次日连续配种的体型相近的健康母貂200只,分为4组,每组50个重复,对照组(Ⅰ组)饲喂基础日粮,试验组(Ⅱ、Ⅲ和Ⅳ组)于配种结束第2天在每只水貂基础日粮中分别添加2、4和6 mg的P_4,连续饲喂14 d。结果显示:母貂妊娠期,Ⅱ、Ⅲ、Ⅳ组与Ⅰ组相比,分别延长0.13 d(P>0.05),缩短3.56 d(P<0.01),缩短1.89 d(P<0.01);Ⅱ、Ⅲ、Ⅳ组母貂在3~4 d内集中产仔,同期高出Ⅰ组32%~47%;母貂胎平均产仔数,Ⅱ、Ⅲ、Ⅳ组与Ⅰ组相比,分别多0.55只(P>0.05),1.28只(P<0.05),2.14只(P<0.01);母貂产仔率,Ⅱ、Ⅲ、Ⅳ组与Ⅰ组相比,提高4%~8%;仔貂3日龄成活率,Ⅱ、Ⅲ、Ⅳ组与Ⅰ组相比,差异均不显著(P>0.05)。结果表明:添加4~6 mg水平外源P_4可以提高短毛黑水貂的妊娠期、胎平均产仔数等繁殖性能;在本试验中,以每天饲喂6 mg P_4,连续饲喂14 d,效果最佳。

In order to examine the roles of exogenous progesterone（ P_4） on the reproductive performance in female minks and select optimal P_4 feeding levels,200 female minks similar in physical condition were divided into four groups,50 minks in each and got the first mating on March 7,the second mating on March 8. Group Ⅰ was feed with basic diet. Group Ⅱ,Ⅲ and Ⅳ were additionally added 2,4 and 6 mg P_4 in every mink at the second day and for next 14 days after matting and recorded the breeding date,date of birth,litter size,survival rate of infants at the age of 3 day,the number of pregnant female mink,and litter amount to do the data analysis. The results showed that the female minks＇ pregnancy duration of Groups Ⅱ,Ⅲ and Ⅳcompared with Group I are prolonged by 0. 13 days,and shortened 3. 56 by 1. 89 days,respectively. Groups Ⅱ,Ⅲ and Ⅳ of female minks had 32% to 47% higher delivery rates in Day3 and Day4 than the rate of GroupⅠ. The average delivery number of Groups Ⅱ,Ⅲ and Ⅳ was 0. 55（ P〉0. 05）,1. 28（ P〈0. 05）,and 2. 14（ P〈0. 01） more than the number of Group Ⅰ. A 4% to 8% higher of delivery rate compared from Groups Ⅱ,Ⅲ and Ⅳ to Group Ⅰ. There were no distinct differences in survival rates of infants at the age of 3 day among these 4 groups. In short,additionally adding 4-6 mg P_4 can increase the pregnancy duration,average delivery number and the other reproductive ability of mink. The optimal level of feeding P_4 under this research is 6 mg for 14 d.