|
Artificial insemination is an advanced technology on pig breeding in worldwide, witch has many advantages such as, accelerated genetic improvement, reduced cost for breeding boars, and depressed the risk of disease transmission. However, Artificial insemination may require a higher level of management, human if not comply with the Artificial insemination procedure strictly, will lead to the invasion of pathogenic microorganisms, thereby reducing the pregnancy rate and litter size rate. In addition, as the usage of artificial insemination of pigs has increased rapidly in recent years, the demand for semen from genetically superior boars has grown and can only be satisfied by using more boars for collection. This reduced selection efficiency an raised both capital and labour costs. Besides, in large scale pig farms, there always were some sows continuous estrus caused by metritis. Therefore, based on the understanding of the process of sperm transportion, the reproductive system of sows and the process of insemination, finding new strategies to reduce semen loss, to improve the pregnancy rate and litter size rate reduced by human error and continuous estrus caused by metritis is essential.Therefore, this study use LY and YL sows, LY and YL gilts and Duroc boars as main experimental animals, compared the effects of intrauterine insemination and standard insemination on the pregnancy rate, farrowing rate and the litter size of sows. Further more, we study the effect of different dose and volume on the pregnancy rate, farrowing rate and litter size of sows. Additionaly, in order to reduce the pathogenic microorganisms by human error manipulation in artificial insemination process, improve the sows not heat, delayed estrus, or heat but not pregnant after weaning. We added some drugs to the diets of sows before insemination, to study the effect of drug treatment before insemination on the fertility of sows. The main results are as follows:1. Compared with standard AI, intrauterine insemination could improve total number of piglet born, live-born litter size, healthy litter size and weak litter size significantly, up to 1.12, 1.47, 0.92 and 0.6 respectively. The effect of intrauterine insemination was no relative to season.2. Wether intrauterine insemination or standard AI, compared with 3 billion spermatozoa/80ml, using a dose of 1.5 billion spermotozoa with 80ml extender could obtain consistent effect on fertility of sows. This result could improve 1 time on the usage efficiency of great boars. Therefore, accelerated genetic improvement, reduced cost for breeding boars, reduced the essential dose in latest national standard <GB23238-2009>.3. Treated weaning sows witch had a difficult birth record, an artificial midwifery record,or continuous estrus caused by metritis, with some drugs before insemination, could significantly improved the heat rate, pregnancy rate, farrowing rate and total number of piglet born, up to 3.54%, 5.96%, 7.54% and 1.37 respectively. But had no significance on gilts. Our results showed that there were more or less reproductive tract infection in weaning sows witch had a difficult birth record, an artificial midwifery record,or continuous estrus caused by metritis. However, gilts had never deliveried before, the reproductive tract were clean, so drug treatment effect was not significant.4. Compared with standard artificial insemination, the pre-operation time of intrauterine insemination was just 19s longer standard artificial insemination, the infusion of the AI dose with intrauterine insemination lasted for 43s shorter than standard artificial insemination. So that the whore procedure of intrauterine insemination was 24s shorter than standard artificial insemination, there was no significant difference between the two insemination methods. Therefore, intrauterine insemination could be extended.
|