Measures of Reproductive Performance in Swine Relative to Industry Averagesa
Industry Data | ||||
|---|---|---|---|---|
Measure | Explanation | Below Average | Average | Above Average |
Weaned sows bred by 7 days (%) | Percentage of sows bred within 7 days of weaning | < 84% | 86%–90% | 91%–95% |
Wean-to-service interval (days) | Days from wean to first service (may be extended in summer and fall and by parity 1 sows) | ≥7–10 days | >6.0–6.9 days | 4.5–6.0 days |
Repeat services (%) | Percentage of sows reserviced within a wean group | ≥9.0%–14% | 5.1%–8.9% | 2%–5% |
Multiple matings (%) | Percentage of sows receiving multiple services (will be lower in single-service timed artificial insemination programs and can change with wean-to-service interval) | ≤88% | 90%–94% | 95%–99% |
Regular returns to service, 18–24 days (%) | Sows with a regular return to estrus (18–24 days) | ≥9%–13% | 5%–7% | 1%–4% |
Irregular returns to service, 25–37 days (%) | Sows with an irregular return to estrus (25–37 days) | >5% | 2%–3% | < 2% |
Abortions (%) | Percentage of pregnant sows that abort | >3% | 1.5%–3.0% | < 1.5% |
Not in pig (%) | Percentage of sows that reach full term, presumed pregnant, but do not farrow | ≥2.1% | 1%–2% | 0.5%–0.99% |
Day 30 conception rate (%) | Sows bred diagnosed pregnant by use of ultrasound | < 85% | 88%–92% | >92% |
Farrowing rate (%) | Percentage of sows mated that farrow | < 82% | 83%–87% | 88%–95% |
Total pigs born/litter | Total number of pigs born per litter farrowed | < 13.5 | 13.9–14.9 | 15.0–16.0 |
Live pigs born/litter | Number of live-born pigs per litter farrowed | ≤12.6 | 12.9–13.9 | 14.0–15.0 |
Stillbirths (%) | Percentage of total pigs born that are stillborn (changes with litter size) | ≥8.0% | 6.0%–7.8% | < 4.0%–5.99% |
Number of stillborn pigs per litter | Number of stillborn pigs per sows farrowed | ≥1.2–1.5 | 0.91–1.1 | 0.5–0.90 |
Mummified fetuses (%) | Percentage of total born pigs that are mummified (may increase as total born litter size increases) | ≥3.0%–4.5% | 1.0%–2.99% | ≤0.7%–0.9% |
Number of mummified fetuses per litter | Number of mummified fetuses per sow farrowed | ≥0.5–0.6 | 0.3–0.4 | 0.1–0.2 |
Pigs weaned per sow farrowed | Based on calculation; measures may change if including nurse sows | ≤9.8–10.8 | 11.0–11.5 | ≥11.6–12.2 |
Nonproductive sow days range | Measure will increase if data includes days from gilt entry until service | >56–74 days | 42–50 days | ≤30–38 days |
Replacement rate (%) | 39%–50% | 52%–59% | 62%–73% | |
Culling rate (%) | 26%–37% | 40%–47% | 51%–65% | |
Sow mortality (%) | Includes sows that die or are euthanized | ≥13.5%–16.8% | 10.4%–12.4% | 6.7%–9.4% |
Weaning age range (days) | Excludes nurse sows | 17.5–19.5 days | 20.1–20.9 days | 21.3–23.1 days |
Gestation length (days) | May change based on use of induction of farrowing | < 114.5 or >116.5 days | 115.9 days | 116.0 days |
aValues are based on breeding-herd record summaries from 2019 and include data from ~1,500 farms; the average herd size was >2,000 sows, representing fertility data for >2.5 million sows. Reference sources: MetaFarms, Production Index Analysis 2019; Swine Management Services, LLC; PigCHAMP, 2019 Benchmarking Summaries, USA. | ||||
Management of commercial swine breeding herds involves a thorough understanding of reproductive physiology, genetics, nutrition, immunology, disease control, environment, and other factors. ( See also page Abortion in Pigs.) The closed-herd concept, which emphasizes preventive medicine strategies along with herd protection, minimizes the risk of disease loss when combined with intensive management, sound nutrition, and genetic selection. The breeding program should be evaluated at specified intervals to ensure that progress in both efficiency and productivity is being made. Several efficiency/production parameters to review when analyzing herd reproductive performance are shown in Measures of Reproductive Performance in Swine Relative to Industry Averagesa. The postweaning performance of a breeding herd's offspring can be measured through assessment of such parameters as feed conversion ratio, average daily gain, total days to market, and postweaning death loss.
Problems on a swine farm can have a single cause or be caused by a combination of genetic, nutritional, environmental, health, and management factors. When investigating a herd problem, the practitioner can best benefit from remaining focused on the herd and not on individual animals. Accurate, up-to-date records are essential when investigating a herd problem. When analyzing a herd and its records, a certain percentage of “abnormal” animals and/or reproductive problems are to be expected.
