Evaluation of adiponectin gene expression in the abdominal adipose tissue of broiler chickens: feed restriction, dietary energy, and protein influences adiponectin messenger ribonucleic acid expression.

We studied the effects of feed restriction and different energy and protein contents of the diet on BW, abdominal adipose tissue percentage, and adiponectin gene expression in abdominal adipose tissue in broiler chickens. Two experiments were conducted to determine whether feed restriction and dietary energy and protein levels alter adiponectin mRNA abundance in broiler chicks. Body weight and abdominal adipose tissue percentage were recorded and abdominal adipose tissue samples were collected at sampling days. Adiponectin mRNA expression in abdominal adipose tissue was quantitated using real-time quantitative PCR. We found that BW, abdominal adipose tissue percentage, and adiponectin gene expression were decreased in restricted chicks compared with those fed ad libitum at 32 d of age, but feed restriction had no effect on abdominal adipose tissue percentage and adiponectin gene expression at 49 d of age (experiment 1). Body weight was increased significantly in broilers fed on low-energy diets compared with those fed high-energy diets in experiment 1. Also, increasing levels of dietary protein increased BW in broiler chicks in experiment 2. A positive response in adiponectin gene expression and abdominal adipose tissue percentage was achieved by decreasing protein level in the diet of chicks at 32 d of age, but dietary protein had no effect on adiponectin gene expression at 49 d of age (experiment 1). Also, in experiment 2, abdominal adipose tissue percentage increased as dietary protein with fixed level of energy decreased in broiler chickens at 42 and 56 d of age. In experiment 1, increasing dietary energy levels increased adiponectin gene expression and abdominal adipose tissue percentage in chicks at 32 d of age. Also, we showed that dietary energy had an effect on abdominal adipose tissue percentage at 49 d of age. In experiment 2, a high-energy diet with a fixed level of protein increased abdominal adipose tissue percentage in chicks at 42 and 56 d of age. Dietary energy and protein levels had no significant effect on adiponectin gene expression in abdominal adipose tissue in broilers.