山西瘦肉型猪SD-Ⅱ系繁殖性状的表型和遗传参数估测

Study on Phenotypic and Genetic Parameters for Reproductive Traits of Shanxi Lean-Type Swine(SD-Ⅱ strain)

本文对山西瘦肉型猪SD—Ⅱ系繁殖性状的表型参数和遗传参数进行了研究 ,结果如下 :(1)繁殖性状存在负的母体效应 ,表型变化不稳定 (呈亲代高子代低 ,亲代低子代高的趋势 ) ,不适宜用表型选择进行选择 ;(2 )总产仔数、活产仔数、初生窝重、初生个体平均重、泌乳力、断奶窝重、断奶个体平均重、断奶头数、总乳头数的遗传力分别为 0 2 30、 0 2 42、 0 2 19、 0 2 5 7、 0 184、 0 12 8、 0 40 8、 0 419、 0 5 0 2 ,与国内文献报道结果相近 ,而高于国外文献报道结果。 (3)繁殖性状间的遗传相关都比较强 ,断奶头数与大多数繁殖性状的遗传相关呈显著或极显著的正相关 。

The study was carried on the phenotypic and genetic parameters for reproductive traits of Shanxi Lean-Type Swine (SD—ⅡStrain), the results are as follows: (1) Negative maternal effect exists among the reproductive traits. The phenotypic value isn't stable and there is a trend that is the higher the parental value, the lower the filial value; the lower the parental value, the higher the filial value. So the phenotypic selection isn't suitable for reproductive trait selection. (2) The heritability of the total litter size, the survival litter size, the average body weight at birth, the litter weight at birth, the litter weight at 20 days of age, the average weaning weight, the weaning litter size, the weaning weight of litter and the total teat number is 0 230,0 242, 0 219, 0 257, 0 184, 0 128, 0 408, 0 419 and 0 502 respectively, which is similar to the reported results of internal documents and higher than the reported results of foreign documents. (3) The high genetic correlation exists among reproductive traits. The genetic correlation between the weaning litter size with most of other reproductive traits is significant or most significant positive, so it should be the mainly selected trait of reproductive traits in breeding.