Stress and summer infertility in pigs

Area of Science:

• Veterinary Medicine
• Animal Reproduction
• Swine Production

Background:

• A commercial piggery experienced a significant year-round fertility issue.
• This problem manifested as a high rate of non-pregnant sows and gilts failing to return to estrus post-mating.

Purpose of the Study:

• To investigate the causes of a persistent fertility problem in a commercial piggery.
• To identify stressors affecting breeding stock and their impact on reproductive performance.

Main Methods:

• Identified several factors causing undue stress on breeding stock from weaning through early pregnancy.
• Implemented measures to mitigate the identified stressors.

Main Results:

• A marked improvement in the herd's farrowing rate was observed after stress reduction.
• The improvement was primarily due to a decrease in sows/gilts failing to return to estrus.
• No significant changes were noted in other performance metrics.

Conclusions:

• Stress factors beyond summer heat can induce delayed or absent estrus in swine.
• This condition, often mislabeled 'summer or seasonal infertility', can occur year-round.
• Managing environmental and managemental stressors is crucial for maintaining swine reproductive efficiency.