Double and triple matings associated with reproductive performance in first-serviced and reserviced female pigs in commercial herds.

The objective of this study was to investigate associations of the number of matings and services with reproductive performance in high-performing and ordinary herds. The data included 113,265 service and 92,248 farrowing records in 117 herds. A service included single or more matings of a female pig (female) during a 10-day estrus period. Two herd groups were built on the basis of the upper 25th percentile of pigs weaned per mated female per year: high-performing (> or = 22.8 pigs) and ordinary herds. Mixed-effects models were used to analyze reproductive performance. Relative frequencies (%) of single, double and triple or more matings were 3.4, 27.4, and 69.2% in high-performing herds, respectively, and were 4.6, 59.3 and 36.1% in ordinary herds, respectively. Percentages of reserviced females in high-performing and ordinary herds were 7.3 and 13.0%, respectively. Triple or more-mated (TM) gilts had 3.5% higher farrowing rates than double-mated (DM) gilts (P<0.01), but similar pigs born alive (PBA) to DM gilts in the first service group in both the herd groups. In the first service group, TM sows had 0.8% higher farrowing rates and 0.2 more PBA than DM sows in high-performing herds (P<0.01). In the reservice group, TM gilts and TM sows had farrowing rate similar to DM gilts and DM sows in high-performing herds. In conclusion, performing triple matings was a better practice for first-serviced females than performing double matings. Double matings may be sufficient for reserviced females.

Factors associated with a single-mating occurrence in first-serviced and reserviced female pigs on commercial farms.

This study investigated associations of a single-mating occurrence (SMO) with farrowing rate and pigs born alive (PBA) in first-serviced and reserviced female pigs (females), and identified the factors associated with SMO. The data included 111,334 service and 91,233 farrowing records on 117 farms. A mating was defined as any one insemination (mating) of a female during estrus. Mixed-effects models were used to investigate reproductive performance and factors associated with SMO. In the first-service group, single-mated females had a lower farrowing rate and fewer PBA than multiple-mated females (P<0.05). In the reservice group, single-mated females also had a lower farrowing rate than multiple-mated females (P<0.05), but had PBA similar to multiple-mated females. SMO in first-service and reservice groups were 4.1 and 6.0%, respectively. Gilts were 1.030 times more likely to be mated a single time than sows (P<0.05). Gilts with age at first mating 150-224 and > or = 262 days were 1.010-1.016 times more likely to be mated a single time than those with age at first mating 225-260 days (P<0.05). Sows with weaning-to-first-mating interval > or = 7 days were 1.024-1.030 times more likely to be mated a single time than those with weaning-to-first-mating interval < or = 6 days (P<0.05). Factors associated with a higher SMO were a reservice occurrence, being gilts, low or high ages of gilts at first mating, and prolonged weaning-to-first-mating interval.