Measures of Reproductive Performance in Swine Relative to Industry Averages^a

Weaned sows bred by 7 days (%)

Percentage of sows bred within 7 days after weaning

< 84%

85–90%

91–95%

Wean-to-service interval (days)

Days from wean to first service (can be extended in summer and autumn 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 matings (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 ultrasonography

< 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 (can 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

By calculation; measures can 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 death (%)

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)

Can change by use of induction of farrowing

< 114.5 or > 116.5 days

115.9 days

116.0 days