大白猪乳头数与繁殖性状的关系研究

Study on the relationship between teat number and reproductive traits in large white Yorkshire pigs

为了探讨大白猪乳头数与繁殖性状的关系,论证乳头数辅选繁殖性状的可行性,试验采用世代选育和系间杂交试验方法测定了大白猪产仔数与活仔数、出生窝重、21日龄窝重以及M、F两系纯繁、系间杂交后代乳头数,并探讨了乳头数的变化规律。结果表明:品系乳头数均值反映产仔数水平,F系产仔数、乳头数均极显著高于M系(P<0.01);M、F系乳头数变异系数分别为4.24%、4.18%;随世代、胎次递增,乳头数呈下降趋势,是闭锁群繁殖性能退化的重要诱因;子代产仔数与母本胎次呈负相关(r=-0.24);大白猪保持乳头数的动力来源于母本,乳头数改变的动力来源于父本,产仔数由母本决定,父本仅影响子代乳头数,仔代产仔数高低由高乳头数亲本血液含量和父本杂交位次共同决定。说明乳头数可作为产仔数的辅选性状。

In order to explore the relationship between teat number and reproductive traits in large white Yorkshire pigs,and to demonstrate the feasibility of secondary selection of reproductive traits by teat number,the total number of piglets born,the number of piglets born alive,the lit-ter weigh of piglets born,the 21-day litter weight,and the teat number of M and F two systems of pure and inter-system hybrid progeny were determined by the methods of generational breeding and inter-system hybridization.The results showed that the mean of teat number reflected litter size level.Litter size and teat number of F-system were significantly higher than those of M-system(P<0.01).The variation coefficient of M-system and F-system teat number was 4.24%,4.18%,respectively.With the increase of generation and parities,teat number showed a downward trend,which was an important inducement for the degradation of reproductive performance of the locking group.The litter size of off-spring was negatively correlated(r=-0.24)with the mother’s parities.The impetus of keeping teat number come from female parents,and the impetus of changing teat number came from male parents.Litter size was decided by female parents,and teat number of offspring was only af-fected by male parents.The litter size of offspring was decided by the blood content of parents with high teat number and the crossing position of parents.In conclusion,teat number can be used as a secondary trait of litter size.