From Systemic Stress to Ovarian Failure: Heat Stress-Induced Infertility in Pigs as a Model for Reproductive...

Area of Science:

• Reproductive biology
• Animal physiology
• Environmental stress

Background:

• Heat stress (HS) impairs mammalian reproduction, particularly in swine.
• HS disrupts endocrine regulation, metabolism, immunity, and gut integrity.
• Ovarian pathways like JAK-STAT and PI3K/AKT are affected by HS.

Purpose of the Study:

• To review systemic and ovarian mechanisms of HS-induced female reproductive impairment in pigs.
• To identify research gaps for enhancing fertility under heat stress.

Main Methods:

• Literature review of systemic and ovarian effects of heat stress on female reproduction.
• Analysis of cellular pathways affected by heat stress in the ovary.
• Synthesis of current knowledge on heat stress and swine fertility.

Main Results:

• HS reduces feed intake and alters metabolic hormones, impacting ovarian function.
• Increased intestinal permeability during HS allows endotoxins, causing inflammation.
• Ovarian pathways are disrupted, affecting follicular development, oocyte quality, and corpus luteum function.

Conclusions:

• Heat stress significantly reduces conception rates and increases embryonic loss in pigs.
• Systemic and ovarian dysfunctions are key contributors to HS-induced infertility.
• Further research is needed to mitigate HS effects and improve swine fertility.