Panida ChanapiwatEm On OlanratmaneeKampon KaeoketPadet TummarukMahidol UniversityRajamangala University of Technology Tawan-okChulalongkorn University2018-11-092018-11-092014-01-01Journal of Veterinary Medical Science. Vol.76, No.10 (2014), 1347-135113477439091672502-s2.0-84908374045https://repository.li.mahidol.ac.th/handle/123456789/34732© 2014 The Japanese Society of Veterinary Science. The aim of the present study was to determine the conception rate and litter size in sows after fixed time intra-uterine insemination using frozen-thawed boar semen in a commercial swine herd in Thailand. Sixty-nine Landrace multiparous sows were randomly allocated into two groups, including control (n=36) and treatment (n=33). The control sows were inseminated with extended fresh semen (3 × 109 motile sperm/dose, 100 ml) at 24, 36 and 48 hr after the onset of estrus. The treatment sows were inseminated with frozen-thawed semen (2 × 109 motile sperm/dose, 20 ml) at 24 and 36 hr after induction of ovulation by human chorionic gonadotropin. All inseminations were carried out by using an intra-uterine insemination technique. The time of ovulation was determined by using transrectal real-time B-mode ultrasonography. The conception rate, farrowing rate, total number of piglets born/litter (TB) and number of piglets born alive/litter (BA) were evaluated. The sows inseminated with extended fresh semen yield a higher TB (10.8 versus 9.0 piglets/l, P=0.015) and tended to have a higher conception rate (88.9% versus 75.8%, P=0.150) than sows inseminated with frozen-thawed semen. In conclusion, insemination using frozen-thawed boar semen can be practiced with convinced fertility under field conditions by fixed-time intrauterine insemination with 2 × 109 sperm/ dose of 20 ml at 24 and 36 hr after the onset of estrus.Mahidol UniversityMedicineVeterinaryArticleSCOPUS10.1292/jvms.14-0069