title: Uterine insemination with a standard AI dose in a sow pool system.
abstract: The effect of uterine AI with a standard dose of spermatozoa on fertility of the sow was studied in a field trial. The trial involved a sow pool system with 440 sows using AI as the primary method of breeding. Sows were twice a day checked for oestrus symptoms by back pressure test in front of a boar on days 3-6 after weaning. When in standing heat, sows were randomly allocated into either a uterine insemination group (UTER, n = 157) or standard AI group (CONT, n = 169) and bred accordingly using 3 billion spermatozoa in 80 ml of extender. In both treatment groups, insemination was repeated once if the sow was still receptive 24 h later. Using pregnancy (farrowed or not) and live-born litter size as the outcome variables, a logistic and linear regression approach, respectively, was taken to study the effect of the following factors: treatment (UTER vs CONT), AI operator, breed, satellite herd preceding weaning, parity, weaning-to-oestrus interval and length of lactation. Overall, live-born litter size was 11.3 +/- 2.9, repeat breeding rate 4.2% and farrowing rate 91.2%. In the UTER group, 93.6% of inseminated sows farrowed, whereas farrowing rate for the CONT group was 88.8% (p = 0.13). Intrauterine insemination with a standard AI dose did not result in a significant improvement in the live-born litter size (11.5 +/- 2.8 for the UTER and 11.1 +/- 3.0 for the CONT sows, respectively, p = 0.13). However, the preceding satellite herd had a highly significant effect on the live-born litter size (12.4 +/- 2.6; 11.1 +/- 2.9; 10.8 +/- 2.9 and 10.9 +/- 2.9 for the four satellite herds, p < 0.01). We conclude that uterine insemination did not have a significant effect on live-born litter size and farrowing rate and we also conclude that satellite herd appears to have a major effect on fertility in a sow pool system.
authors.affiliation: Department of Production Animal Medicine, University of Helsinki, Pohjoinen pikatie, Saarentaus, Finland. olli.peltoniemi@helsinki.fi
authors.forename: O A T
authors.initials: OA
authors.lastname: Peltoniemi
authors.forename: K
authors.initials: K
authors.lastname: Alm
authors.forename: M
authors.initials: M
authors.lastname: Andersson
mesh_terms: D000818:Animals; D001947:Breeding / Q000379:methods; D004972:Estrus Detection; D005260:Female; D005298:Fertility; D007315:Insemination, Artificial / Q000379:methods / Q000662:veterinary*; D007774:Lactation; D008098:Litter Size; D010298:Parity; D011247:Pregnancy; D012044:Regression Analysis; D013045:Species Specificity; D013552:Swine; D013997:Time Factors; D016896:Treatment Outcome; D014599:Uterus; D014886:Weaning