TERRAPUB AGri-Bioscience Monographs (AGBM)


Vol. 6 (No. 2), pp. 59-83, 2016 doi: 10.5047/agbm.2016.00602.0059

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

Masayuki Shimada1,2*, Yasuhisa Yamashita3 and Tetsuji Okazaki4

1Laboratory of Reproductive Endocrinology, Graduate School of Biosphere Science, Hiroshima University, 1-4-4, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8528, Japan
2The Research Center for Animal Science, Hiroshima University, 1-4-4, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8528, Japan
3Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, 562 Nanatuka-cho, Shobara 727-0023, Japan
4Smaller Livestock and Environment Section, Livestock Research Institute, Oita Prefectural Agriculture, Forestry and Fisheries Research Center, Bungo-ono, Oita 879-7111, Japan
*e-mail: mashimad@hiroshima-u.ac.jp

(Received on August 28, 2014; Accepted on December 15, 2014; Online published on December 13, 2016)

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.

Keywords: pig, reproductive technology, ovulation, sperm, frozen semen


[Full text] (PDF 2.7 MB)