College of Animal Science and Technology, Jiangsu Provincial Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Provincial Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Provincial Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
Institute of Agricultural Products Processing, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu 210014, China.
J Anim Sci. 2022 Oct 1;100(10). doi: 10.1093/jas/skac277.
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 (T3h group). Meanwhile, the birds from GAA and CrN supplementation groups were transported for 3 h (identified as GAA600, 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 T3h group, GAA600, CrN600, and CrN900 groups increased the pH45min (P < 0.01), and CrN600, CrN900 groups decreased the cooking loss (P < 0.05) of PM muscle. Meanwhile, the muscle of GAA600, CrN600, and CrN900 groups showed a higher glycogen content (P < 0.01) and a lower lactic acid content (P < 0.01). GAA600 and all CrN treatments enhanced muscle Cr content and reduced AMP/ATP ratio (P < 0.01). In addition, GAA600 and all CrN treatments downregulated the relative mRNA expression levels of LKB1 and AMPKα2 (P < 0.001) and the protein expression of p-AMPKαThr172 compared with the T3h group (P < 0.01). All CrN treatments showed lower protein expression levels of LKB1 and p-LKB1Thr189 than those of the T3h 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.
本研究旨在探讨新型肌酸形式——饮食肌酸硝酸盐（CrN）对宰前运输诱导肉鸡胸肌能量消耗和快速糖酵解的缓解作用。将 288 只阿伯丁·阿科马克肉鸡（28 日龄）随机分为 5 个日粮处理组，包括基础日粮或基础日粮添加 600mg/kg 胍基乙酸（GAA）、300、600 或 900mg/kg CrN，分别饲养 14d。在运输当天，基础日粮组的肉鸡分为两组：一组运输 0.5h（对照组），另一组运输 3h（T3h 组）。同时，GAA 和 CrN 补充组的鸡只运输 3h（分别命名为 GAA600、CrN300、CrN600 和 CrN900 组）。结果表明，28 至 42 日龄时，日粮中添加 GAA 或 CrN 对运输肉鸡胸肌的生长性能、屠宰性能和质地特性（P>0.05）没有显著影响。与 T3h 组相比，GAA600、CrN600 和 CrN900 组提高了胸肌的 pH45min（P<0.01），CrN600 和 CrN900 组降低了胸肌的蒸煮损失（P<0.05）。同时，GAA600、CrN600 和 CrN900 组的肌肉糖原含量更高（P<0.01），乳酸含量更低（P<0.01）。GAA600 和所有 CrN 处理均提高了肌肉 Cr 含量，降低了 AMP/ATP 比值（P<0.01）。此外，与 T3h 组相比，GAA600 和所有 CrN 处理均下调了 LKB1 和 AMPKα2 的相对 mRNA 表达水平（P<0.001），并降低了胸肌 p-AMPKαThr172 的蛋白表达水平（P<0.01）。与 T3h 组相比，所有 CrN 处理组的 LKB1 和 p-LKB1Thr189 蛋白表达水平均较低（P<0.05）。综上所述，日粮补充 GAA 和 CrN 可提高肌肉肌酸含量，抑制运输诱导的 LKB1/AMPK 通路激活，有利于延缓快速肌肉糖酵解，改善肉质。
