Cao Songjing, Guan Lingling, Li Changzhong, Sun Guoliang, Tian Haining, Sun Ruijian, Tu Jun, Meng Yuqiong, Ma Rui
State Key Laboratory of Plateau Ecology and Agriculture, College of Ecological Environmental Engineering, Qinghai University, Xining 810016, China.
Tongwei Agricultural Development Co., LTD., Chengdu 610000, China.
Aquac Nutr. 2023 May 30;2023:4733343. doi: 10.1155/2023/4733343. eCollection 2023.
The research is aimed at investigating the effects of dietary protein and lipid levels on adult triploid rainbow trout growth performance, feed utilization, digestive and metabolic enzyme activities, antioxidative capacity, and fillet quality. Nine diets containing three dietary protein levels (DP) (300, 350, and 400 g kg) and three dietary lipid levels (DL) (200, 250, and 300 g kg) were prepared using a 3 × 3 factorial design. In freshwater cages, 13,500 adult female triploid rainbow trout (3.2 ± 0.1 kg) were cultured for 77 days. Triplicate cages (500 fish per cage) were used as repetitions of each experimental diet. The findings revealed that as DP increased to 400 g kg and DL raised to 300 g kg, the weight gain ratio (WGR) elevated significantly ( < 0.05). However, when DP ≥ 350 g kg, WGR was similar in the DL250 and DL300 groups. As DP raised to 350 g kg, the feed conversion ratio (FCR) notably decreased ( < 0.05). In the DP350DL300 group, lipids had a protein-sparing impact. High DP diet (400 g kg) generally improved fish health status by increasing antioxidant capacity in the liver and intestine. A high DL diet (300 g kg) showed no harmful effect on hepatic health based on plasma levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and antioxidant capacity in the liver. For fillet quality, a high DP diet could increase fillet yield, improve fillet hardness, springiness, and water-holding capacity values, and inhibit the production of off-flavors caused by n-6 fatty acids. A high DL diet could increase odor intensity, and EPA, DHA, and n-3 fatty acid concentrations decrease the thrombogenicity index value. The maximum fillet redness value was discovered in the DP400DL300 group. Overall, for adult triploid rainbow trout (≥3 kg), the minimum recommended DP and DL according to growth performance were 400 and 250 g kg, respectively; DP and DL based on feed utilization were 350 and 200 g kg, respectively; DP and DL based on fillet quality were 400 and 300 g kg, respectively.
本研究旨在调查日粮蛋白质和脂肪水平对成年三倍体虹鳟生长性能、饲料利用率、消化和代谢酶活性、抗氧化能力及鱼片品质的影响。采用3×3析因设计配制了9种日粮，包含3个日粮蛋白质水平（DP）（300、350和400 g/kg）和3个日粮脂肪水平（DL）（200、250和300 g/kg）。在淡水网箱中，养殖13500尾成年雌性三倍体虹鳟（3.2±0.1 kg）77天。每个实验日粮设置3个重复网箱（每个网箱500尾鱼）。结果表明，随着DP增加到400 g/kg和DL提高到300 g/kg，增重率（WGR）显著升高（P<0.05）。然而，当DP≥350 g/kg时，DL250和DL300组的WGR相似。随着DP提高到350 g/kg，饲料转化率（FCR）显著降低（P<0.05）。在DP350DL300组中，脂肪具有节约蛋白质的作用。高DP日粮（400 g/kg）通常通过提高肝脏和肠道的抗氧化能力改善鱼的健康状况。基于血浆丙氨酸转氨酶（ALT）和天冬氨酸转氨酶（AST）水平以及肝脏抗氧化能力，高DL日粮（300 g/kg）对肝脏健康无有害影响。对于鱼片品质，高DP日粮可提高鱼片产量，改善鱼片硬度、弹性和持水能力值，并抑制由n-6脂肪酸引起的异味产生。高DL日粮可增加气味强度，而二十碳五烯酸（EPA）、二十二碳六烯酸（DHA）和n-3脂肪酸浓度可降低血栓形成指数值。DP400DL300组的鱼片红色值最高。总体而言，对于成年三倍体虹鳟（≥3 kg），根据生长性能，推荐的最低DP和DL分别为400和250 g/kg；根据饲料利用率，DP和DL分别为350和200 g/kg；根据鱼片品质，DP和DL分别为400和300 g/kg。
