Heat Stress Reduces Metabolic Rate While Increasing Respiratory Exchange Ratio in Growing Pigs
| dc.contributor.author | Fausnacht, Dane W. | en |
| dc.contributor.author | Kroscher, Kellie A. | en |
| dc.contributor.author | McMillan, Ryan P. | en |
| dc.contributor.author | Martello, Luciane S. | en |
| dc.contributor.author | Baumgard, Lance H. | en |
| dc.contributor.author | Selsby, Joshua T. | en |
| dc.contributor.author | Hulver, Matthew W. | en |
| dc.contributor.author | Rhoads, Robert P. | en |
| dc.contributor.department | Animal and Poultry Sciences | en |
| dc.contributor.department | Human Nutrition, Foods, and Exercise | en |
| dc.date.accessioned | 2021-01-22T18:05:14Z | en |
| dc.date.available | 2021-01-22T18:05:14Z | en |
| dc.date.issued | 2021-01-17 | en |
| dc.date.updated | 2021-01-22T15:47:30Z | en |
| dc.description.abstract | Heat stress (HS) diminishes animal production, reducing muscle growth and increasing adiposity, especially in swine. Excess heat creates a metabolic phenotype with limited lipid oxidation that relies on aerobic and anaerobic glycolysis as a predominant means of energy production, potentially reducing metabolic rate. To evaluate the effects of HS on substrate utilization and energy expenditure, crossbred barrows (15.2 ± 2.4 kg) were acclimatized for 5 days (22 °C), then treated with 5 days of TN (thermal neutral, 22 °C, <i>n</i> = 8) or HS (35 °C, <i>n</i> = 8). Pigs were fed ad libitum and monitored for respiratory rate (RR) and rectal temperature. Daily energy expenditure (DEE) and respiratory exchange ratio (RER, CO2:O2) were evaluated fasted in an enclosed chamber through indirect calorimetry. Muscle biopsies were obtained from the longissimus dorsi pre/post. HS increased temperature (39.2 ± 0.1 vs. 39.6 ± 0.1 °C, <i>p</i> < 0.01) and RER (0.91 ± 0.02 vs. 1.02 ± 0.02 VCO2:VO2, <i>p</i> < 0.01), but decreased DEE/BW (68.8 ± 1.7 vs. 49.7 ± 4.8 kcal/day/kg, <i>p</i> < 0.01) relative to TN. Weight gain (<i>p</i> = 0.80) and feed intake (<i>p</i> = 0.84) did not differ between HS and TN groups. HS decreased muscle metabolic flexibility (~33%, <i>p</i> = 0.01), but increased leucine oxidation (~35%, <i>p</i> = 0.02) compared to baseline values. These data demonstrate that HS disrupts substrate regulation and energy expenditure in growing pigs. | en |
| dc.description.version | Published version | en |
| dc.format.mimetype | application/pdf | en |
| dc.identifier.citation | Fausnacht, D.W.; Kroscher, K.A.; McMillan, R.P.; Martello, L.S.; Baumgard, L.H.; Selsby, J.T.; Hulver, M.W.; Rhoads, R.P. Heat Stress Reduces Metabolic Rate While Increasing Respiratory Exchange Ratio in Growing Pigs. Animals 2021, 11, 215. | en |
| dc.identifier.doi | https://doi.org/10.3390/ani11010215 | en |
| dc.identifier.uri | http://hdl.handle.net/10919/102016 | en |
| dc.language.iso | en | en |
| dc.publisher | MDPI | en |
| dc.rights | Creative Commons Attribution 4.0 International | en |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | en |
| dc.subject | heat stress | en |
| dc.subject | lipid oxidation | en |
| dc.subject | energy expenditure | en |
| dc.subject | respiratory exchange ratio | en |
| dc.title | Heat Stress Reduces Metabolic Rate While Increasing Respiratory Exchange Ratio in Growing Pigs | en |
| dc.title.serial | Animals | en |
| dc.type | Article - Refereed | en |
| dc.type.dcmitype | Text | en |