This experiment aimed to evaluate the impact of dietary hydroxyproline (Hyp) supplementation on the muscle quality of juvenile Pacific white shrimp () fed a low fishmeal diet. Six formulated diets included one high fishmeal (HF; 25% fishmeal content) and five low fishmeal diets (10% fishmeal content) with 0%, 0.2%, 0.4%, 0.6% and 0.8% Hyp (LF0, LF2, LF4, LF6 and LF8, respectively). Each diet was assigned to four replicates, and 40 shrimp (0.32 ± 0.00 g) per replicate were fed four times a day for 8 weeks. Dietary Hyp supplementation had little effects on growth performance, but increased the contents of Hyp, prolyl 4-hydroxylases (P4Hs), and collagen. The meat yield, springiness, hardness, chewiness, and cohesiveness of muscle were the highest in the LF4 group among the low fishmeal groups ( < 0.05). Cooking loss and freezing loss of muscle were the lowest in the LF4 group ( < 0.05). Dietary supplementation with 0.4% Hyp increased the myofiber density and decreased the myofiber diameter of muscle ( < 0.05). Supplementation of Hyp in the diet up-regulated the mRNA expression of , , , , , and and down-regulated the mRNA expression of , , ( < 0.05). Supplementation of Hyp in the diet up-regulated the protein expression of P-4E-BP1, P-AKT, AKT and P-AKT/AKT ( < 0.05). These results suggested that the addition of 0.4% Hyp to low fishmeal diets improved the muscle quality of .

中文翻译：

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低鱼粉日粮中添加羟脯氨酸对凡纳滨对虾幼年胶原蛋白合成、肌纤维发育和肌肉质地的影响


本实验旨在评估膳食羟脯氨酸 (Hyp) 补充剂对低鱼粉饲料喂养的幼年太平洋白虾肌肉质量的影响。六种配制日粮包括一种高鱼粉日粮（HF；鱼粉含量为 25%）和五种低鱼粉日粮（鱼粉含量为 10%），其中 Hyp 含量为 0%、0.2%、0.4%、0.6% 和 0.8%（LF0、LF2、LF4、LF6）和 LF8，分别）。每个饲料被分配到四个重复，每个重复 40 只虾（0.32 ± 0.00 g）每天喂食四次，持续 8 周。膳食补充 Hyp 对生长性能影响不大，但增加了 Hyp、脯氨酰 4-羟化酶 (P4Hs) 和胶原蛋白的含量。低鱼粉组中，LF4组的出肉率、弹性、硬度、咀嚼性和肌肉的凝聚力最高（ < 0.05）。 LF4组的肌肉烹饪损失和冷冻损失最低（<0.05）。膳食补充 0.4% Hyp 增加了肌肉的肌纤维密度并降低了肌肉的肌纤维直径 ( < 0.05)。饮食中添加 Hyp 上调 、 、 、 、 和 的 mRNA 表达，下调 、 、 的 mRNA 表达（ < 0.05）。饮食中补充 Hyp 上调 P-4E-BP1、P-AKT、AKT 和 P-AKT/AKT 的蛋白表达 ( < 0.05)。这些结果表明，在低鱼粉日粮中添加 0.4% Hyp 可以改善 的肌肉质量。