This study was carried out to investigate the effect of sperm concentration of 5ml maxi-straw on farrowing rate and number of pigs born alive per litter in deep frozen boar semen. We did not find out the effect of sperm concentration on post-thaw sperm motility and NAR acrosome. However, farrowing rate and number of pigs born alive per litter of 7. 5 x 10˚ /5ml and 10.0 x 10˚ /5m1 sperm concentrations were higher than those of 5. 0 /10˚ /5ml sperm concentration.

This study was carried out to compare farrowing rate and litter traits for European and American lines with boar sperm frozen in straws. Farrowing rate, litter size and mean pig weght at birth and 21 days were investigated. A total of 36 gilts Landrace, Large white and Duroc were investigated at the Chungnam Provincial Animal Breeding Station. We obtained higher farrowing rate and litter traits for European line boars compared to American line boars.

The objective of this study was to produce calves derived from in vitro fertilization of in vitro matured follicular oocytes. Oocytes aspirated from small antral folicles of ovaries obtained at a local slaughter house were matured and fertilized in vitro. At l8hrs after insemination with Korean native cattle semen, oocytes were co-cultured for 6~7 days by utilizing co-culture system with bovine oviduct epithelial cell. After co-culture, good or excellent quality late morulae or early blastocysts were selected by morphological criteria under stereo microscope. Selected embryos were transferred to recipients on day 6 or 7 (estrus = day 0). Recipients were monitored by observation for estrus and rectal palpation after 60 days from embryo transfer. One of them went to term with the birth of a calf. This case is the first production of calf derived from in vitro fertilization in Korea.

This study was carried out to investigate the effects of imported 0.25 ml straw frozen semen on fertilizing capacity after artificial insemination. A total of 57 ewes of Corriedale were inseminated at the Namwon Branch, National Anirnal Breeding Institute. Lambing percentage and twinning percentage were 12.3% and 114. 3%, resepectively. Average weight at birth and weaning of 120 days old were 4.5kg and 21.9 kg, respectively. Gestation period was 152.6 days.