Campus Units
Animal Science
Document Type
Article
Publication Version
Accepted Manuscript
Publication Date
5-23-2020
Journal or Book Title
Theriogenology
DOI
10.1016/j.theriogenology.2020.05.023
Abstract
Unfavorable weather conditions are one of the largest constraints to maximizing farm animal productivity. Heat stress (HS), in particular, compromises almost every metric of profitability and this is especially apparent in the grow-finish and reproductive aspects of the swine industry. Suboptimal production during HS was traditionally thought to result from hypophagia. However, independent of inadequate nutrient consumption, HS affects a plethora of endocrine, physiological, metabolic, circulatory, and immunological variables. Whether these changes are homeorhetic strategies to survive the heat load or are pathological remains unclear, nor is it understood if they temporally occur by coincidence or if they are chronologically causal. However, mounting evidence suggest that the origin of the aforementioned changes lie at the gastrointestinal tract. Heat stress compromises intestinal barrier integrity, and increased appearance of luminal contents in circulation causes local and systemic inflammatory responses. The resulting immune activation is seemingly the epicenter to many, if not most of the negative consequences HS has on reproduction, growth, and lactation. Interestingly, thermoregulatory and production responses to HS are only marginally related. In other words, increased body temperature indices poorly predict decreases in productivity. Further, HS induced malnutrition is also a surprisingly inaccurate predictor of productivity. Thus, selecting animals with a “heat tolerant” phenotype based solely or separately on thermoregulatory capacity or production may not ultimately increase resilience. Describing the physiology and mechanisms that underpin how HS jeopardizes animal performance is critical for developing approaches to ameliorate current production issues and requisite for generating future strategies (genetic, managerial, nutritional, and pharmaceutical) aimed at optimizing animal well-being, and improving the sustainable production of high-quality protein for human consumption.
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Copyright Owner
Elsevier Inc.
Copyright Date
2020
Language
en
File Format
application/pdf
Recommended Citation
Mayorga, E. J.; Ross, J. W.; Keating, A. F.; Rhoads, R. P.; and Baumgard, L. H., "Biology of heat stress; the nexus between intestinal hyperpermeability and swine reproduction" (2020). Animal Science Publications. 539.
https://lib.dr.iastate.edu/ans_pubs/539
Comments
This is a manuscript of an article published as Mayorga, E. J., J. W. Ross, A. F. Keating, R. P. Rhoads, and L. H. Baumgard. "Biology of heat stress; the nexus between intestinal hyperpermeability and swine reproduction." Theriogenology (2020). doi: 10.1016/j.theriogenology.2020.05.023.