Glicerol na dieta de codornas : expressão de mRNA de genes mitocondriais e de crescimento

Abstract

This study was conducted to evaluate the expression of messenger RNA (mRNA) of insulin like growth factor-1 gene (IGF-1), growth hormone recptor (GHR), adenine nucleotide translocase (ANT), cytochrome c oxidase III (COX III) and uncoupling protein (UCP) in the breast muscle of quails with 28 days of age, fed diets containing 0, 8 and 12% glycerol. Total RNA was extracted (n = 10 per group) and cDNA amplified using specifics primers by qRT-PCR. Feed conversion (FC) and feed intake (FI) were also evaluated. The mRNA expression of UCP was lower in the group fed with 12% of glycerol (0.026UA) when compared to the ones fed with 0% (0.041UA) and 8% glycerol (0.057UA). In contrast, expression of ANT and COX III mRNA in breast muscle was higher in the group fed with 12% of glycerol (ANT = 7.525UA; COX III = 0.863UA), with no differences in 0% (ANT = 5.572UA; COX III = 0.357UA) and 8% of glycerol (ANT 5.839UA; COX III = 0.415UA). The mRNA expression of UCP was lower in quails with worse FC and in these same quails ANT and COX III were higher. Quails fed with supplemented diets containing 8% and 12% of glycerol showed higher IGF-1 mRNA expression in relation to those in diets without glycerol and 12% level of glycerol in the diet negatively influenced GHR mRNA expression. The addition of 8% glycerol in the diet provided quails performance results similar to those observed in the diets without glycerol, suggesting that the inclusion of glycerol in the diet of meat quails can influence the expression of mRNA of mitochondrial and growth genes in breast muscle, besides promoting changes in feed conversion and feed intake. Considering the performance and expression of UCP, ANT and COX III mRNA in quails` breast muscle, the diet with 8% of glycerol could be used without further damages in the feed of quails at 28 days of age.