DⅢ系母本猪的繁殖性能、生殖生理及影响因子的研究

Studies on reproduetive performance certain reproductive physiological indices and faetors influencing reproduction of maternal pig DⅢ:

瘦肉猪母本新品系ＤⅢ系，在８年６世代的选育过程中，对世代母猪各胎次的繁殖成绩进行了系统测定，并以发情排卵、胚胎发育、生殖激素变化图型等方面对该品系的生殖生理、影响繁殖的因素所作的多项基础性试验研究结果，经产母猪排卵数１９．５０±２．６９枚、产仔数１３．３９±２．４０头，３０天胚胎成活率７７．９２％；母猪８月龄发情周期及妊娠早期孕酮（Ｐ４）、雌三醇（Ｅ２）变化图型已分别满足其初配及妊娠早期所需水准。同时初析了母猪配种时期、公猪利用频度及环境气象条件等因素对产仔性能的影响程度。

On breeding of 6 generations during 8 years, reproductive performance of new female pareat line DⅢ of lean meat pig in different generations and parturitions was tested systematically, its repoduetive physiological indices and factors influencing reproduction were studied through measure of ovulation embryo development, change type of reproductive hormones and so on. The results showed: In mutiparous sow, the number of ovulated ova was 19 50±2 69, litter size was 13 39±2 40, embryo livability on 30 days was 77 92% Change types of progesteron (P 4) and estradiol (E 2) during estrous cycle of 8-month sow, and in early time of pregency met those necessilated in first mating and early time of progency. The effect of mating time of sow frequency of bear breeding、 environment on farrowing performance was disscussed preliminarily.