Understanding the effects of dietary nutrients on physiological and biochemical parameters, especially the metabolism of nutrients during crayfish farming, can be useful for improving crayfish health and optimizing production in aquaculture. Therefore, we conducted an 8-week feeding study to investigate the effect of dietary carbohydrate-to-lipid (CHO: LIP) ratios on growth performance, hemolymph biochemical indices, intestinal digestion, hepatopancreas lipid, and carbohydrate metabolism of red swamp crayfish (Procambarus clarkii) (initial weight = 9.10 ± 0.15 g). Four isoenergetic and isonitrogenous diets (16.2 MJ kg⁻¹ gross energy and 30.2% crude protein) were estimated to include different CHO:LIP ratios: 1.88 (22.5% CHO/11.9% LIP); 3.25 (29.3% CHO/9% LIP); 5.94 (36.2% CHO/6.1% LIP); and 13.60 (43.1% CHO/3.2% LIP). According to the results, the weight gain rate (WGR), final body weight, specific growth rate (SGR), intestinal amylase activity, abdominal muscle crude protein content, and protease activity significantly increased (P < 0.05) as the CHO:LIP ratio increased from 1.88 to 5.94 and then significantly decreased (P < 0.05) as the CHO:LIP ratio increased from 5.94 to 13.60. However, the feed conversion ratio exhibited the opposite trend. The abdominal muscle crude lipid content, hemolymph cholesterol content, and intestinal lipase activity significantly decreased with increasing dietary CHO:LIP ratios from 1.88 to 13.60, whereas the hemolymph glucose level showed the opposite trend. The activities of phosphofructokinase (PFK), the mRNA expression levels of pfk, pyruvate kinase (pk), lactate dehydrogenase (ldh), fatty acid synthase (fas), cholesterol regulatory element-binding protein 1 (srebp1), retinoic acid X receptor (rxr), and hexokinase (hk) in the hepatopancreas significantly increased with the increasing CHO:LIP ratios from 1.88 to 13.60, whereas the activities of lipoprotein lipase, hepatic esterase, and phosphoenolpyruvate carboxykinase, the mRNA expression levels of acyl coenzyme a oxidase (aco), fatty acid-binding protein gene (fabp), acyl-coA synthetase bubblegum (acsbg), glucose6-phosphatase (g6pase), pepck and fructose-1, 6-diphosphatase (fbpase) significantly decreased. The quadratic regression model showed that the optimal CHO: LIP ratio and dietary protein level for red swamp crayfish were 7.74% and 30%, respectively. These results suggest that optimal dietary CHO: LIP ratios could increase the SGR and WGR of red swamp crayfish. High CHO: LIP ratio inhibits gluconeogenesis and lipid degradation, while low CHO: LIP ratio inhibits glycolysis and lipogenesis.

了解日粮营养素对生理和生化参数的影响，尤其是小龙虾养殖过程中营养素的代谢，有助于改善小龙虾健康和优化水产养殖生产。因此，我们进行了一项为期 8 周的喂养研究，以调查日粮碳水化合物与脂质 (CHO: LIP) 比率对红沼泽小龙虾 ( Procambarus ) 生长性能、血淋巴生化指标、肠道消化、肝胰腺脂质和碳水化合物代谢的影响。 clarkii) (初始重量 = 9.10 ± 0.15 g)。四种等能量和等氮饮食（16.2 MJ kg ^-1总能量和 30.2% 粗蛋白）估计包括不同的 CHO：LIP 比率：1.88（22.5% CHO/11.9% LIP）；3.25 (29.3% CHO/9% LIP); 5.94 (36.2% CHO/6.1% LIP); 和 13.60 (43.1% CHO/3.2% LIP)。 结果显示，随着CHO:LIP的比值，体重增加率（WGR）、最终体重、比生长率（SGR）、肠淀粉酶活性、腹肌粗蛋白含量和蛋白酶活性显着增加（P < 0.05）从 1.88 增加到 5.94，然后显着下降（P < 0.05)，因为 CHO:LIP 比率从 5.94 增加到 13.60。然而，饲料转化率却呈现出相反的趋势。腹肌粗脂肪含量、血淋巴胆固醇含量和肠脂肪酶活性随着日粮 CHO:LIP 比率从 1.88 增加到 13.60 显着下降，而血淋巴葡萄糖水平则呈现相反的趋势。磷酸果糖激酶（PFK）的活性、pfk、丙酮酸激酶（pk）、乳酸脱氢酶（ldh）、脂肪酸合酶（fas）、胆固醇调节元件结合蛋白1（srebp1）、视黄酸X受体（rxr ) 和己糖激酶 ( hk) 在肝胰腺中随着 CHO:LIP 比值从 1.88 增加到 13.60 显着增加，而脂蛋白脂肪酶、肝酯酶和磷酸烯醇丙酮酸羧激酶的活性、酰基辅酶 a 氧化酶 ( aco )、脂肪酸结合蛋白的 mRNA 表达水平基因 ( fabp )、酰基辅酶 A 合成酶泡泡糖 ( acsbg )、葡萄糖 6-磷酸酶 ( g6pase )、pepck和果糖-1, 6-二磷酸酶 ( fbpase) 显着下降。二次回归模型显示，红沼泽小龙虾的最佳CHO:LIP比和日粮蛋白质水平分别为7.74%和30%。这些结果表明，最佳日粮 CHO：LIP 比例可以增加红沼泽小龙虾的 SGR 和 WGR。高 CHO：LIP 比率抑制糖异生和脂质降解，而低 CHO：LIP 比率抑制糖酵解和脂肪生成。