Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Jun 28;9(7):395.
doi: 10.3390/ani9070395.

Chronic Heat Stress Induces Acute Phase Responses and Serum Metabolome Changes in Finishing Pigs

Yanjun Cui  1   2 , Chong Wang  3   4 , Yue Hao  5 , Xianhong Gu  6 , Haifeng Wang  7
Affiliations

Chronic Heat Stress Induces Acute Phase Responses and Serum Metabolome Changes in Finishing Pigs

Yanjun Cui et al. Animals (Basel). .

Abstract

Heat stress (HS) is a main environmental challenge affecting the animal welfare and production efficiency in pig industry. In recent years, numerous reports have studied the alterations in gene expressions and protein profiles in heat-stressed pigs. However, the use of metabolome to unravel adaptive mechanisms of finishing pig in response to chronic HS have not yet been elucidated. We aimed to investigate the effects of chronic HS on serum metabolome in finishing pigs, and to identify the biomarkers of heat stress. Pigs (n = 8 per treatment) were exposed to either thermal neutral (TN; 22 °C) or heat stress (HS, 30 °C) conditions for three weeks. Serum metabonomics of TN- and HS-treated pigs were compared using the GC-MS approach. Metabonomics analysis revealed that twenty-four metabolites had significantly different levels in TN compared to HS (variable importance in the projection values >1 and p < 0.05). These metabolites are involved in carbohydrate, amino acid, fatty acid, amines metabolism, and gut microbiome-derived metabolism. Three serum monoses (glucose, mannose 2, and galactose) and 6-phosphogluconic acid were decreased, indicating insufficient source of fuel for energy supply, resulting in negative energy balance (NEB) in heat-stressed pigs. Increased levels of non-esterified fatty acid (myristic acid, palmitic acid, and linoleic acid) and short-chain fatty acids (3-hydroxybutanoic acid and maleic acid) suggested fat decomposition compensating for energy shortage, which was an adaptive response to NEB. Increased concentrations of fluorine, lyxose 1, and D-galacturonic acid were significantly correlated with the levels of acute phase proteins (HP, LBP, α2-HSG, and Lysozyme), suggesting acute phase response in HS-stressed pigs. These metabolites are expected to be novel biomarkers of chronic HS in pigs, yet the use of which awaits further validation.

Keywords: acute-phase proteins; chronic heat stress; finishing pigs; metabolomics.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
The effects of three weeks of thermal neutral (TN) or heat stress (HS) conditions on activities of SOD, CAT, GSH-PX, and MDA level in the serum of finishing pigs. Data are mean ± SD; n = 8 for each group. * p < 0.05 and ** p < 0.01 before vs. after heat stress.
Figure 2
Figure 2
The effects of three weeks of thermal neutral (TN) or heat stress (HS) conditions on activities of (A) HP, (B) α2HGS, (C) LBP, and (D) lysozyme in the serum of finishing pigs. Data are mean ± SD; n = 8 for each group. * p < 0.05 and ** p < 0.01 before vs. after heat stress.
Figure 3
Figure 3
Score plot of orthogonal projections to latent structures discriminant analyses (OPLS-DA) derived from the GC-MS profiles of serum samples obtained from the heat stress (HS) group vs. thermal neutral (TN) group (A); Validation plots of the partial least squares discriminant analysis (OPLS-DA) models acquired through 999 permutation tests for the GC-MS data of serum metabolome (B).
Figure 4
Figure 4
Hierarchical cluster analysis of twenty-four metabolites with significantly different levels in serum of finishing pigs. Red indicates high relative abundance, and blue indicates low relative abundance.
Figure 5
Figure 5
Schematic overview of some important metabolites and major metabolic pathways related to fat acid, amino acid, and energy metabolism in heat-stressed pigs. Red up-arrow: heat stress (HS) group vs. thermal neutral (TN) group up-regulation. Blue down-arrow: HS group vs. TN group down-regulation.
See this image and copyright information in PMC

References

    1. Baumgard L.H., Rhoads R.P., Jr. Effects of heat stress on postabsorptive metabolism and energetics. Annu. Rev. Anim. Biosci. 2013;1:311–337. doi: 10.1146/annurev-animal-031412-103644. - DOI - PubMed
    1. Montilla S.I.R., Johnson T.P., Pearce S.C., Gardan-Salmon D., Gabler N.K., Ross J.W., Rhoads R.P., Baumgard L.H., Lonergan S.M., Selsby J.T. Heat stress causes oxidative stress but not inflammatory signaling in porcine skeletal muscle. Temperature. 2014;1:42–50. doi: 10.4161/temp.28844. - DOI - PMC - PubMed
    1. Akbarian A., Michiels J., Degroote J., Majdeddin M., Golian A., De Smet S. Association between heat stress and oxidative stress in poultry; mitochondrial dysfunction and dietary interventions with phytochemicals. J. Anim. Sci. Biotechnol. 2016;7:37. doi: 10.1186/s40104-016-0097-5. - DOI - PMC - PubMed
    1. Starkie R., Hargreaves M., Rolland J., Febbraio M. Heat stress, cytokines, and the immune response to exercise. Brain Behav. Immun. 2005;19:404–412. doi: 10.1016/j.bbi.2005.03.005. - DOI - PubMed
    1. Pearce S., Mani V., Weber T., Rhoads R., Patience J., Baumgard L., Gabler N. Heat stress and reduced plane of nutrition decreases intestinal integrity and function in pigs. J. Anim. Sci. 2013;91:5183–5193. doi: 10.2527/jas.2013-6759. - DOI - PubMed