Journal
ANIMALS
Volume 11, Issue 1, Pages -Publisher
MDPI
DOI: 10.3390/ani11010215
Keywords
heat stress; lipid oxidation; energy expenditure; respiratory exchange ratio
Funding
- USDA AFRI [2017-05931, 2014-67015-21627, 20116700330007]
Ask authors/readers for more resources
Heat stress disrupts substrate regulation and energy expenditure in growing pigs, leading to decreased muscle metabolic flexibility and increased leucine oxidation. However, weight gain and feed intake did not differ significantly between the HS and TN groups.
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 degrees C), then treated with 5 days of TN (thermal neutral, 22 degrees C, n = 8) or HS (35 degrees C, n = 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 degrees C, p < 0.01) and RER (0.91 +/- 0.02 vs. 1.02 +/- 0.02 VCO2:VO2, p < 0.01), but decreased DEE/BW (68.8 +/- 1.7 vs. 49.7 +/- 4.8 kcal/day/kg, p < 0.01) relative to TN. Weight gain (p = 0.80) and feed intake (p = 0.84) did not differ between HS and TN groups. HS decreased muscle metabolic flexibility (similar to 33%, p = 0.01), but increased leucine oxidation (similar to 35%, p = 0.02) compared to baseline values. These data demonstrate that HS disrupts substrate regulation and energy expenditure in growing pigs.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available