a1 Key Laboratory of Animal Physiology & Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
The effects of pyruvate (Pyr), creatine pyruvate (Cr-Pyr) and creatine (Cr) on lipid and protein metabolism were compared in broiler chickens. A total of 400 1-day-old male birds (Aconred) were allocated to four groups, each of which included four replicates (25 birds per replicate). Treatments consisted of unsupplemented basal diet (Control), basal diet containing 2% Pyr, basal diet containing 3% Cr and basal diet containing 5% Cr-Pyr. Cr-Pyr and Pyr significantly decreased the hepatic triglyceride and serum total cholesterol concentration (P < 0.01). Cr-Pyr markedly increased the serum non-esterified fatty acid and high-density lipoprotein cholesterol concentrations (P < 0.05), whereas the expression of carnitine palmitoyl transferase I (P < 0.05) and peroxisome proliferators-activated receptor-α (P < 0.01) mRNA in the liver were both decidedly enhanced in the Cr-Pyr group. The relative leg muscle weight was higher in the Cr-Pyr group than in the control group, whereas the serum uric acid content and hepatic glutamic-oxaloacetic transaminase activity were lower in the Cr-Pyr and Cr groups (P < 0.05), respectively. Muscle insulin-like growth factor I (P < 0.05) expression was enhanced, and the myostatin (P < 0.01) mRNA level was reduced in both the Cr-Pyr and Cr groups. In addition, Cr-Pyr did not alter body weight or the feed conversion ratio. These results indicate that, compared with Pyr and Cr alone, Cr-Pyr has a bifunctional role in broiler chickens, in that it influences both lipid and protein metabolism.
(Received August 13 2010)
(Accepted December 23 2010)
(Online publication February 07 2011)