title: An analysis of survey data by size of the breeding herd for the reproductive management practices of North American sow farms.
abstract: A survey was performed to assess whether reproductive management differed among small-sized (Sm, <500 sows), medium-sized (M, 501 to 2,000 sows), and large-sized (Lg, 2,001 to 8,000 sows) farms (n=113). Farms with 501 to 4000 sows/barn were most frequent with sows kept in stalls on 90% of farms. More Lg farms (P<0.05) functioned as breed to wean and more Sm and M as farrow to finish. More Sm and Lg farms weaned at >21 d, whereas M farms were more likely to wean at 18 to 21 d (P<0.05). More Lg farms had farrowing rates above 89% than Sm and M farms (P<0.05), and culling rates above 40% were more frequent on M and Lg farms than on S. On M and Lg farms, sows were bred in larger batches, using lower person to sow ratios, and with more people required than on Sm farms (P<0.05). More (P<0.05) M and Lg farms spent time moving sows and on records, but hours devoted to estrous detection, breeding, and other tasks did not differ among farms (P>0.10). More M and Lg farms used more boars for estrus detection, rotated boars, and controlled boar movement than Sm farms (P<0.05). Farm size also influenced semen sourcing, number of doses received, and frequency of semen delivery (P<0.05). More M and Lg farms performed AI in the presence of a boar, left the AI rod in after AI, checked for returns, and diagnosed pregnancy than Sm farms (P<0.05). Start of boar exposure after weaning began on 69% of farms within 2 d, occurring most often in the AM, but with exposure times varying from 1 to 5 min/sow. Semen was thermally protected for 50% of farms receiving shipments, and semen storage was consistent among farms. For AI, service occurred within minutes to hours after detection of estrus on 61% of farms. During AI, procedures such as back-pressure were required, whereas techniques such as hands-free AI were prohibited on most farms. Sow movement was allowed only once at 4 wk after breeding on 50% of farms, and pregnancy diagnosis occurred at 3 to 5 wk on 78% of farms. Most sows were allowed ≥1 chance for breeding after conception failure before culling. Incidence of fail to farrow was <5% and litter size was 10 to 13 pigs on >82% of farms. Summer infertility was observed on 69% of farms with estrus and pregnancy failures the leading causes. Over 70% of farms reported a technician effect on fertility. These results suggest that reproductive management of farms in key areas related to weaning, breeding, gestation, and labor use could be a source of variation in reproductive performance.
authors.affiliation: Department of Animal Sciences, University of Illinois at Champaign-Urbana, Urbana, IL 61801, USA. rknox@illinois.edu
authors.forename: R V
authors.initials: RV
authors.lastname: Knox
authors.forename: S L
authors.initials: SL
authors.lastname: Rodriguez Zas
authors.forename: N L
authors.initials: NL
authors.lastname: Sloter
authors.forename: K A
authors.initials: KA
authors.lastname: McNamara
authors.forename: T J
authors.initials: TJ
authors.lastname: Gall
authors.forename: D G
authors.initials: DG
authors.lastname: Levis
authors.forename: T J
authors.initials: TJ
authors.lastname: Safranski
authors.forename: W L
authors.initials: WL
authors.lastname: Singleton
mesh_terms: D000822:Animal Husbandry / Q000191:economics; D000818:Animals; D001947:Breeding; D003625:Data Collection; D005260:Female; D008297:Male; D009656:North America; D012098:Reproduction / Q000502:physiology*; D013552:Swine / Q000502:physiology*