山西瘦肉型新品系晋阳白猪选育研究

以梅山猪为第一母本系,与外种猪汉普夏和大约克夏进行杂交,采用继代选育和分子生物学相结合的方法,经过18年7个世代的选育,以繁殖性能、生长性能和胴体品质作为主选性状,育成了山西瘦肉型猪新品系晋阳白猪。7世代的初产母猪和经产母猪的总产仔数、活产仔数、断奶窝质量分别达11.3头、10.6头、72.8kg和13.3头、12.6头、87.3kg;180日龄后备母猪个体质量达91.87kg,公猪93.38kg;后备猪同胞肥育性能(体质量20～90kg)日增质量703g;90kg体质量的瘦肉率为58.9%,眼肌面积31.87cm2,平均背膘厚2.0cm。对母本系繁殖性能进行随机扩增多态性DNA(RAPD)分析得到的公共条带数较多,多态条带数较少,多态频率较低。ESR基因和FSHβ基因的基因型在总产仔数、活产仔数和断奶头数方面对晋阳白猪的影响显著,而对晋阳白猪的初生质量和断奶质量影响不显著。说明晋阳白猪的主选性状全面达到了育种目标,表明遗传变异稳定、选育程度较高。

Selection of the New Lean-type Breed of Shanxi Jinyang White Pigs

A seven-generation resource family was developed in Shanxi using Meishan Grand dams, Hampshire and Large Yorkshire sires during 18 years and aimed to breed the Jinyang White pigs, a new lean-type breed in Shanxi. Systematic breeding and molecular biology methods were used in this research. Reproduction performance, growth performance and carcass quality were chosen as the major traits. Total number born, number born alive, and weaning weight litter of first gestation gilt and multiparous sow in 7th generation reached 11.3 heads, 10.6 heads, 72.8 kg and 13.3 heads, 12.6 heads, 87.3 kg, respectively. Body weight of replacement gilts and boars at 180 d in 7th generation were 91.87 kg and 93.38 kg respectively. The daily gain of replacement pigs of 20～90 kg was 703 g. Lean meat percentage, eye muscle area, average back fat thickness of replacement pigs at 90 kg were 58.9%, 31.87 cm^2, and 2.0 cm respectively. Many common bands were observed in the RAPD results of reproduction performance with maternal inbred line, but bands and frequency of polymorphism were less. The genotype of ESR gene and FSHβ gene affected the total number born, number born alive and the number of pig weaned, significantly. However, they have no effect to litter weight at birth and weaning weight.It was concluded that all of the major traits reached the breeding objectives, and the inheritance variation was stable and breeding degree was high.