Fertility after intrauterine insemination with conventional or low numbers of spermatozoa in sows with synchronized ovulation

Abstract

Listen

Translate article

Objective: To determine sow fertility to a single timed intracervical or intrauterine insemination of conventional or low sperm numbers. Materials and methods: A total of 411 mixed-parity sows were subjected to controlled ovulation by injection of 600 IU equine chorionic gonadotrophin at weaning and 5 mg porcine luteinizing hormone (pLH) 80 hours later. Sows were assigned to a single insemination of 1 or 3 × 109 sperm delivered into either the cervix or uterus. Inseminations were performed approximately 36 hours after pLH injection. Intensity of standing estrus at insemination was subjectively scored as 1 to 3, with 3 being a stronger response, and semen backflow was recorded as yes or no. Results: Number of sperm and site of deposition did not affect pregnancy or farrowing rates or subsequent litter size. Mean farrowing rates were 68.32% and 68.63% in sows inseminated using an intrauterine catheter and either 1 or 3 × 109 sperm, respectively. In sows inseminated using the cervical method, farrowing rates were 77.88% and 67.31% when 1 and 3 × 109 sperm were used, respectively. Greater intensity of estrus at insemination was associated with higher pregnancy and farrowing rates (P < .001), and backflow during insemination was associated with lower pregnancy and farrowing rates (P < .01). Implications: When appropriately timed after induced ovulation, insemination of low sperm numbers does not adversely affect sow fertility, and this lack of effect is independent of the site of sperm deposition.