Dietary creatine nitrate enhances muscle creatine loading and delays postmortem glycolysis of broilers that experienced preslaughter transport

1. CrN is a novel form of creatine product which has not been used in poultry production. 2. Dietary with CrN supplementation could improve meat quality by enhancing muscle creatine loading and delaying preslaughter transport-induced rapid glycolysis of broilers. 3.CrN has a good potential as GAA substitute in broiler production. Lay Summary Preslaughter transport has been reported to accelerate energy expenditure and induce rapid muscle glycolysis of broilers, resulting in inferior meat quality. This study investigates the attenuating effects of dietary creatine nitrate (CrN), a novel form of creatine, on energy expenditure and rapid glycolysis in pectoralis major (PM) muscle of broilers induced by preslaughter transport. The results revealed that dietary supplementation of 600 mg/kg guanidinoacetic acid (GAA), 300, 600, or 900 mg/kg CrN for 14 d prior to slaughter had no significant effect on the growth performance and carcass traits of transported broilers. However, dietary supplementation with 600 mg/kg GAA, 600, or 900 mg/kg CrN elevated creatine and phosphocreatine loading and inhibited transport-induced activation of LKB1/AMPK pathway in PM muscle, which is beneficial for delaying muscle glycolysis and improving meat quality. This study investigated the attenuating effects of dietary creatine nitrate (CrN), a novel form of creatine, on energy expenditure and rapid glycolysis in pectoralis major (PM) muscle of broiler induced by preslaughter transport. A total of 288 Arbor Acres broilers (28 day old) were randomly assigned into five dietary treatments, including a basal diet or the basal diet supplemented with 600 mg/kg guanidinoacetic acid (GAA), 300, 600, or 900 mg/kg CrN for 14 d, respectively. On the day of transportation, the broilers from basal diet group were divided into two equal groups: one group was transported for 0.5 h (Control group) and the other group was transported for 3 h (T-3h group). Meanwhile, the birds from GAA and CrN supplementation groups were transported for 3 h (identified as GAA(600), CrN300, CrN600, and CrN900 group, respectively). The results demonstrated that dietary supplementation of GAA or CrN from 28 to 42 d of age did not significantly affect the growth performance, carcass traits, and textural characteristics (P > 0.05) in PM muscle of transported broilers. Compared with T-3h group, GAA(600), CrN600, and CrN900 groups increased the pH(45min) (P < 0.01), and CrN600, CrN900 groups decreased the cooking loss (P < 0.05) of PM muscle. Meanwhile, the muscle of GAA(600), CrN600, and CrN900 groups showed a higher glycogen content (P < 0.01) and a lower lactic acid content (P < 0.01). GAA(600) and all CrN treatments enhanced muscle Cr content and reduced AMP/ATP ratio (P < 0.01). In addition, GAA(600) and all CrN treatments downregulated the relative mRNA expression levels of LKB1 and AMPK alpha 2 (P < 0.001) and the protein expression of p-AMPK alpha(Thr172) compared with the T-3h group (P < 0.01). All CrN treatments showed lower protein expression levels of LKB1 and p-LKB1(Thr189) than those of the T-3h group (P < 0.05). In summary, dietary supplementation with GAA and CrN enhanced the content of muscle creatine, and inhibited transport-induced activation of LKB1/AMPK pathway, which is beneficial for delaying rapid muscle glycolysis and improving meat quality.

Automated summary

CrN, a novel form of creatine, can improve meat quality by enhancing muscle creatine loading and delaying rapid glycolysis. This study demonstrated that dietary supplementation with CrN can attenuate energy expenditure and rapid muscle glycolysis induced by preslaughter transport.