不同蛋白质、脂肪水平对三疣梭子蟹生长和卵巢色素沉积的影响

Effects of dietary protein and lipid levels on growth and ovary pigmentation in Portunus trituberculatus

以鱼粉和豆粕为蛋白源,鱼油和大豆油为脂肪源,配制蛋白质水平分别为35%、40%、45%和脂肪水平分别为7%、9%、11%的二因子三水平的实验饲料,并以鲜杂鱼饲料为对照,对三疣梭子蟹（Portunus trituberculatus）（体质量36.5-42.9 g）进行为期20周的养殖实验,研究三疣梭子蟹对蛋白质、脂肪的需要量,以及对卵巢色素沉积的影响。养殖实验采用海区串笼吊养方式,每个吊笼放养1只雌蟹。实验共10个处理,每个处理18个蟹,3个重复。结果表明,不同蛋白质、脂肪水平饲料对三疣梭子蟹增重率（269.24%-404.90%）、饲料系数（2.01-2.55）、蛋白质效率（1.02%-1.29%）和肥满度（16.26%-23.97%）均有显著影响（P〈0.05）;增加饲料蛋白质和脂肪水平,可显著提高三疣梭子蟹生长,降低饲料系数（P〈0.05）。对照饲料组的三疣梭子蟹获得了最高的增重率（461.69%）,但饲料系数也是最高（6.35）,而且肥满度（21.15%）低于P40L11组（蛋白质40%、脂肪11%组）。三疣梭子蟹水分、肌肉蛋白质、脂肪、灰份和卵巢灰份不受饲料蛋白质、脂肪水平变化的影响（P〉0.05）,但卵巢蛋白质、脂肪影响显著（P〈0.05）,而且高蛋白饲料组的卵巢脂肪含量总是显著低于其他各组。在同一饲料蛋白质水平下,9%脂肪饲料组的三疣梭子蟹卵巢类胡萝卜素总量、虾青素含量和成色比色值都显著高于其他各饲料组（P〈0.05）。与对照饲料组比较,实验饲料组的三疣梭子蟹卵巢类胡萝卜素总量和虾青素含量呈显著优势。综合考虑生长、饲料系数和色素沉积,三疣梭子蟹饲料的适宜蛋白质水平和脂肪水平分别为40%-45%和9%。本研究旨在为制定三疣梭子蟹饲料配方和改善其品质提供理论依据。

We evaluated the dietary protein and lipid requirements of Portunus trituberculatus and determined the effects of dietary protein and lipid levels on the ovary pigmentation of the crab.The protein and lipid were from two sources,fish meal,and soybean meal and fish oil and soybean oil,respectively.We used a two factor,three level,factorial design.Each diet contained 35%,40%,or 45% protein（P） from either source and 7%,9%,or 11% lipid（L） from either source.Portunus trituberculatus（initial body weight 36.5？42.9 g） were feed with the appro-priate diet for 20 weeks and an additional group was fed a raw fish diet as a control.The feeding experiment was conducted in sea cages using a hanging cultivation technique.Each female was held in a hanging cage.The feed-ing trial consisted of 10 treatments with 18 samples per treatment.All treatments were triplicated.Dietary protein and lipid levels had a significant influence on the weight gain（269.24%？404.90%）,feed conversion ratio（2.01？2.55）,protein efficiency ratio（1.02%？1.29%）,and condition factor（16.26%？23.97%）（P0.05）.The feed conversion ratio decreased and growth rate increased as the level of dietary protein or lipid increased（P0.05）.The group fed a raw fish had the highest increase in weight gain（461.69%） and the highest feed conversion ratio（6.35）.The condition factor of this group（21.15%） was lower than that in the group fed 40% protein/11% lipid.The ovarian protein and lipid content was significantly influenced by the level of dietary protein or lipid（P0.05）.The group fed a high level of dietary protein had higher total ovarian fat content than the other groups.However,there were no significant differences in moisture,crude protein,or fat levels or in total ash or ovarian ash content among the treatment groups（P0.05）.In groups fed the same level of dietary protein,those that were fed 9% lipid had significantly higher levels of total carotenoids and astaxanthin and higher chro-maticity values than the groups fed 7% or 11% lipid（P0.05）.Taken together,the results suggest that the optimal level of dietary protein and lipid are 40%？45% and 9%,respectively,for P.trituberculatus.