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.

The Fertility of Frozen Boar Sperm When used for Artificial Insemination

“…; Knox et al. ). Semen doses are most often packaged in 100‐mL disposable plastic tubes, flat bags or bottles.…”

Artificial insemination in pigs today

“…Today, modern breeding with AI allows for 1 to 2 minutes for estrus detection and 4 minutes for AI for each female [29]. The advantages in labor requirements for AI (including time for semen processing) were quickly realized when the number of females to be mated increased above a minimum number of sows [30].…”

“…Most sows express estrus 4 to 6 days after weaning, and commercial farm records indicate 90% of sows express estrus and are inseminated within 7 days of weaning [10,82]. Because of this, many farms have prearranged semen orders delivered to the farms by a target day to ensure AI doses are available for each sow and replacement gilt for that group [29]. Although most sows will receive two AI doses, one for each day detected in standing estrus, a smaller proportion of sows may only receive one dose or up to three doses, on the basis of shorter and longer duration of estrus, respectively.…”

“…For AI, the rod is lubricated and inserted into the vagina for passage into the cervix for conventional AI. On proper positioning of the catheter in the cervix, the AI dose container is attached to the catheter and the semen is allowed to flow into the cervix using gravity and gentle pressure over a 3-to 4-minute period while back pressure is applied [29]. For IUAI, an inner rod is passed into the uterine body through the outer rod locked into the cervix, and a reduced volume of inseminate is deposited using pressure in only a few seconds.…”

Are Pharmacological Interventions Between Conception and Birth Effective in Improving Reproductive Outcomes in North American Swine?

“…; Spencer ), the average litter size at parturition lingers between 10 and 13 piglets (Geisert and Schmitt ; Knox et al. ; NASS USDA ; Knox ). The decline in reproductive efficiency can be explained, at least in part by the fact that North American swine undergo two waves of spontaneous foetal loss.…”