**Part 3**

**Farm / Pet / Laboratory Animal ART** 

136 Current Frontiers in Cryopreservation

[78] Yun-Xia Cao, Qiong Xing, Li Li, Lin Cong, Zhi-Guo Zhang, Zhao-Lian Wei et al.

[79] Katkov I.I. Race for the pace: is the universal cryoprotocol a dream or reality?.

Volume 92, Issue 4.2009.1306-1311

Cryobiology 2011:61;374-375.

Comparison of survival and embryonic development in human oocytes cryopreserved by slow-freezing and vitrification. Ferti and Steril

**7**

Kampon Kaeoket

*Thailand* 

**Cryopreservation of Boar Spermatozoa:** 

Artificial insemination (AI) is one of the first reproductive biotechnologies has been established and developed in the pig production system. In most case, liquid stored semen or fresh semen is used for AI in commercial swine herds (Wagner and Thibier, 2000). The use of FT boar semen for AI is limited due to the low fertility outcomes compared to extended fresh semen (Johnson et al., 2000; Wagner and Thibier, 2000). The first success of boar semen cryopreservation was reported in 1956 (Polge, 1956) and the first pregnancy was achieved with FT boar semen using surgical insemination in 1970 (Polge, 1970). Currently, the attempt to develop the boar semen cryopreservation technique is ongoing. Nevertheless, the success of boar semen cryopreservation is relatively variable because the factors responsible for the cryosurvival of boar spermatozoa have not been entirely elucidated.

Cryopreservation of boar semen is useful for preservation of genetic resources, improve the genetic progress and enhance the transportation of genetic material across countries (Almlid and Hofmo, 1996; Johnson, 1998). In addition, the frozen-thawed (FT) boar semen is also used with other reproductive technologies, such as in vitro fertilization (IVF), embryo transfer (ET) and sex pre-selection (Gerrits et al., 2005). Unfortunately, the advancement of sperm cryopreservation in pigs is slow, partly due to the pig producer is satisfied with the liquid stored semen and low conception rate and litter size remain the major problems when using FT boar semen (Eriksson et al., 2002.). Under field conditions, low fertility is still obtained even using FT boar semen with a sufficient motility and number of spermatozoa

The use of frozen-thawed (FT) boar semen has been developed for artificial insemination (AI) in pig long time ago in Europe and USA (Larsson and Einarsson, 1976). In Thailand, few studies on boar semen cryopreservation have been established (Buranaamnuay et al., 2006 a,b). However, a great variation on the survival rate of post-thawed spermatozoa are obtained, due to the lack of biological background concerning the cryopreservation technique (Buranaamnuay et al., 2006 a,b). During the recent years, studies on FT boar semen have dramatically improved boar semen cryopreservation technique, for instance, optimum freezing protocols (Eriksson and Rodrigrez-Martinez, 2000), types of freezing package (Bwanga et al., 1991;Berger and Fisherleitner, 1992; Bwanga et al., 1991; Eriksson and Rodriguez-Martinez, 2000), semen centrifugation methods (Carvajal et al., 2004),

for insemination (Johnson et al., 2000, Eriksson et al., 2002).

**1. Introduction** 

 **An Important Role of Antioxidants** 

*Faculty of Veterinary Science, Semen laboratory, Department of* 

*Clinical Science and Public Health, Mahidol University* 
