Development of Artificial Insemination Technique in Pig Production Based on the Evidence of Physiology and Molecular Biology in Reproductive Organs

Abstract

pean countries, more than 70% of pig farms carry out artificial insemination using liquid storage semen, and this rate reaches more than 98% in the Netherlands (Feitsma 2009). However, the diffusion of this technique has been still less than half in other countries including Japan. The improvements of both insemination technique and diluent extender of boar semen Abstract Reproductive technology in the animal production field not only improves the reproductive performance of swine but also reduces the production costs. However, the diffusion of this technique has been limited in most countries including Japan due to the reproductive characteristics of pig, such as multiple ovulations in female and large volume of semen in male. In females, the key mechanisms of oocyte maturation in pig are not different as compared with that of the rodent model. However, the timing and regulation of gene expression and enzyme activity are characterized in pig, which results in the longer duration of oocyte maturation and ovulation. In semen, seminal plasma has dual roles in sperm quality and successful implantation. The contaminating of bacteria in semen increases endotoxin activity and reduces the sperm quality. On the other hand, the seminal plasma contains factors to regulate immune activity to reduce the number of leukocytes to make an optimal condition for implantation and to maintain the pregnancy. Based on basic scientific information, we developed novel techniques for oocyte in vitro maturation, freezing and thawing sperm and artificial insemination. These technologies will be expanded to commercial farms to increase the production-efficiency all over the world.

Factors influencing success of artificial insemination of pigs using extended fresh semen in rural smallholder pig farms of Rwanda

“…Artificial insemination enables to increase sire selection intensity by using the best sires available within individual breeds (Ronald et al, 2013). In fact, the use of AI greatly increases the selection differential, where the genetic potential of the best sires can be extensively transferred to a large number of pigs using diluted semen (Shimada et al, 2016). Artificial insemination technique solves problems of infections due to the contact between boar and female pigs during mating (Shimada et al, 2016).…”

“…In fact, the use of AI greatly increases the selection differential, where the genetic potential of the best sires can be extensively transferred to a large number of pigs using diluted semen (Shimada et al, 2016). Artificial insemination technique solves problems of infections due to the contact between boar and female pigs during mating (Shimada et al, 2016). Some infections caused mainly by viruses and bacteria can result in problems associated with sperm damage, pregnancy failure, abortion, embryo loss and endometritis (Knox, 2016).…”

“…Although AI in pigs has more advantages compared to natural mating, it can have some limitations. For example, AI in pigs can result in low number of piglets per farrowing compared to natural mating; and the limited storage period of fresh semen are the main problems to its expansion in the field all over the world (Shimada et al, 2016). Therefore, Maes et al (2011) suggest that the success of AI in pigs is largely determined by the semen quality and the insemination procedure.…”