Energy metabolism exerts profound impacts on flesh quality. Niacin can be transformed into nicotinamide adenine dinucleotide (NAD), which is indispensable to energy metabolism. To investigate whether niacin deficiency could affect energy metabolism and flesh quality, six diets with graded levels of 0.49, 9.30, 21.30, 33.30, 45.30 and 57.30 mg/kg niacin were fed to grass carp () for 63 days. The results showed that niacin deficiency declined flesh quality by changing amino acid and fatty acid profiles, decreasing shear force, increasing cooking loss and accelerating pH decline. The accelerated pH decline might be associated with enhanced glycolysis as evident by increased hexokinase (HK), pyruvate kinase (PK) and lactic dehydrogenase (LDH) activities, and mitochondrial dysfunction as evident by destroyed mitochondrial morphology, impaired respiratory chain complex I and antioxidant ability. Based on PWG and cooking loss, the niacin requirements for sub-adult grass carp were 31.95 mg/kg and 29.66 mg/kg diet, respectively.

中文翻译：

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烟酸缺乏导致的肉质下降与草鱼（Ctenopharyngodon idella）糖酵解升高和线粒体稳态受损有关

能量代谢对肉质产生深远影响。烟酸可转化为能量代谢不可缺少的烟酰胺腺嘌呤二核苷酸（NAD）。为了研究烟酸缺乏是否会影响能量代谢和肉质，将烟酸水平为0.49、9.30、21.30、33.30、45.30和57.30 mg/kg的6种饲料喂给草鱼()，连续63天。结果表明，烟酸缺乏会改变氨基酸和脂肪酸结构、降低剪切力、增加蒸煮损失和加速 pH 值下降，从而降低肉质。 pH值加速下降可能与糖酵解增强有关，如己糖激酶（HK）、丙酮酸激酶（PK）和乳酸脱氢酶（LDH）活性增加，以及线粒体功能障碍，如线粒体形态被破坏、呼吸链复合物I和抗氧化能力受损。根据PWG和烹饪损失，亚成鱼草鱼的烟酸需要量分别为31.95 mg/kg和29.66 mg/kg日粮。