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Overview of Management of Reproduction: Pigs


Gary C. Althouse

, BS, MS, DVM, PhD, DACT, Department of Clinical Studies, New Bolton Center, University of Pennsylvania

Last full review/revision Mar 2015 | Content last modified Apr 2015
Topic Resources

Management of commercial swine breeding herds involves a thorough understanding of reproductive physiology, genetics, nutrition, immunology, disease control, environment, and other factors. (Also see 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 Reproductive Benchmarking Indices Used in Commercial Swine Herds. 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 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.


Reproductive Benchmarking Indices Used in Commercial Swine Herds

Reproductive Index


Intervention Level

Wean-to-estrus interval (95% in estrus by 10 days postweaning)

<7 days

>9 days

Wean-to-service interval

≤5 days

>7 days

Repeat services at 21 (± 2) days



Abnormal returns to service (25–37 days)



Multiple matings (if not using fixed timed insemination)









Farrowing rate



Total piglets born/litter



Live piglets born/litter









Litter scatter (≤8 pigs/litter)



Pigs weaned/litter



Preweaning mortality



Litters/mated female/year



Pigs weaned/mated female/year



Nonproductive sow days (without gilt pool)



Culling rate


<30% and >50%

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