Abstract:
The objectives of this study were to determine the effects of post-weaning insulin injection on ovulation in primiparous sows and the technique of laparoscopy in a commercial-type setting. Sixteen first litter sows (pure breed Landrace) were paired according to age, number of total born, number of piglets nursed and lactation length. One sow from each pair (T-sow) received subcutaneous injections of insulin (NPH : Isophone) 0.6 I.U./kg body weight at 6:00 h. Insulin injection was started on the day after weaning and continued until the last day before mated or until 10 days after weaning for sows not exhibiting oestrus. Control sows (C-sows) received saline solution as a sham treatment. Laparoscopic examination was performed on day 10 after mating or on day 20 after weaning for anoestrus sows. Means for number of corpora lutea were greater for T-sows (17.0 ± 2.5) than C-sows (12.3 ± 3.6; P<0.05). There were no difference among number of anoestrus sows and weaning to service interval. We conclude that insulin can increase ovulation rate in primiparous sows.