Effects of dietary protein/carbohydrate ratio on fat deposition and gene expression of peroxisome proliferator activated receptor γ and heart fatty acid-binding protein of finishing pigs

Abstract The present study was conducted to investigate the effect of dietary protein/carbohydrate (CH 2 O) 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: low protein/CH 2 O ratio (LP; 11.2% CP and 68.2% CH 2 O for phase I, and 10.1% CP and 69.3% CH 2 O for phase II) diet, or high protein/CH 2 O ratio (HP; 22.7% CP and 58.3% CH 2 O) 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/CH 2 O ratio had no effect on growth performance; however, the intramuscular fat (IMF) in longissimus muscle (LM) was increased ( P P P P  = 0.09) 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 ( P