The present study was conducted to investigate the effect of dietary protein/carbohydrate (CH2O) ratio on fat deposition and expression of peroxisome proliferator activated receptor γ (PPARγ) and heart fatty acid-binding protein (H-FABP) genes in muscle and subcutaneous adipose tissue in pigs. Twenty pigs (73.9±1.2 kg BW) were used in a single factorial experiment, and allocated by BW and ultrasound backfat thickness to the two treatments: lowprotein/CH2O ratio (LP; 11.2% CP and 68.2% CH2O for phase I, and 10.1% CP and 69.3% CH2O for phase II) diet, or high protein/CH2O ratio (HP; 22.7% CP and 58.3% CH2O) diet. Pigs were housed individually in pens, and had ad libitum access to feed and water. After 80-d feeding, 6 pigs from each treatment were selected and slaughtered. Dietary protein/CH2O ratio had no effect on growth performance; however, the intramuscular fat (IMF) in longissimus muscle (LM)was increased when the LP diet was fed. Correspondingly, Warner–Bratzler sheer force of LM in the LP pigs was lower than the HP pigs. The LP increased mRNA levels of PPARγ and H-FABP in LM but not in subcutaneous fat, although the difference of H-FABP gene expression in LM was not statistically significant. The mRNA abundance of PPARγ in muscle correlated positively with IMF content. The results indicated that an increase in IMF but not subcutaneous fat in pigs fed the LP diet is related to tissue-specific activation of PPARγ and H-FABP mRNA expression, especially the PPARγ gene.

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