In ovo feeding of creatine pyruvate modulates growth performance, energy reserves and mRNA expression levels of gluconeogenesis and glycogenesis enzymes in liver of embryos and neonatal broilers.

The effects of in ovo feeding (IOF) of creatine pyruvate (CrPyr) on the growth performance, energy reserves and mRNA expression levels of gluconeogenesis and glycogenesis enzymes in liver of late-term embryos and neonatal broilers were investigated. After candling on 16 day of incubation, a total of 960 eggs were randomly assigned to three treatments: (i) non-injected control, (ii) saline group injected with 0.6 ml of 0.75% physiological saline and (iii) Creatine pyruvate group injected with 0.6 ml of physiological saline containing 12 mg CrPyr/egg. After hatching, 120 male chicks with average body weight (BW) were randomly allocated into each treatment group for a 7-day feeding trial. The results showed that broilers subjected to CrPyr treatment had higher BW than those of the control and saline groups on 1, 3 and 7 day post-hatch, as well as the yolk sac weight on 19 day of incubation (19 E), the day of hatch and 3 day post-hatch (p < .05). Compared with the control and saline groups, IOF of CrPyr increased the plasma creatine concentration on the day of hatch, and the plasma pyruvate concentration on the day of hatch and 3 day post-hatch (p < .05). Moreover, IOF of CrPyr increased the liver pyruvate and glucose concentrations on 19 E and the day of hatch, and the liver glycogen concentration during the experiment (p < .05). Broilers in the CrPyr group showed increased mRNA expression levels of pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK) and glycogen synthase 2 (GYS2) on 19 E and the day of hatch (p < .05). These results indicated that IOF of CrPyr increased energy reserves in liver of embryos and neonatal broilers possibly through upregulating the mRNA expression levels of PC, PEPCK and GYS2, which could benefit the increase of BW in broilers on 7 day post-hatch.