渔业科学进展  2022, Vol. 43 Issue (5): 205-216  DOI: 10.19663/j.issn2095-9869.20210611003
0

引用本文 

黎恒基, 徐超, 苏泽亮, 张关荣, 麻永财, 郑钧, 安文强, 陈宇航, 李远友. 卵形鲳鲹配合饲料中酶解鱼浆蛋白和陆生复合蛋白替代鱼粉的研究[J]. 渔业科学进展, 2022, 43(5): 205-216. DOI: 10.19663/j.issn2095-9869.20210611003.
LI Hengji, XU Chao, SU Zeliang, ZHANG Guanrong, MA Rongcai, ZHENG Jun, AN Wenqiang, CHEN Yuhang, LI Yuanyou. Replacing Fishmeal with Fish Protein Hydrolysate and Terrestrial Complex Protein in the Compound Feed of Trachinotus ovatus[J]. Progress in Fishery Sciences, 2022, 43(5): 205-216. DOI: 10.19663/j.issn2095-9869.20210611003.

基金项目

财政部和农业农村部:国家现代农业产业技术体系资助

作者简介

黎恒基,E-mail: 511477347@qq.com;徐超,E-mail: xuc1213@scau.edu.cn;
徐超,E-mail: xuc1213@scau.edu.cn

通讯作者

李远友,教授,E-mail: yyli16@scau.edu.cn

文章历史

收稿日期:2021-06-11
收修改稿日期:2021-07-17
卵形鲳鲹配合饲料中酶解鱼浆蛋白和陆生复合蛋白替代鱼粉的研究
黎恒基 1,2#, 徐超 1#, 苏泽亮 1, 张关荣 1, 麻永财 1, 郑钧 1, 安文强 1, 陈宇航 2, 李远友 1     
1. 华南农业大学海洋学院 广东 广州 510642;
2. 广东德宁水产科技有限公司 广东 佛山 528300
摘要:为了评估卵形鲳鲹(Trachinotus ovatus)配合饲料中酶解鱼浆蛋白和陆生复合蛋白替代鱼粉的可行性,本研究设计了4种等蛋(42%)等脂(12%)配合饲料(D1~D4),其中,D1(对照组)含30%鱼粉,D2~D4(处理组)都含14%陆生复合蛋白且还分别含有16%、11%、6%鱼粉和0、5%、10%酶解鱼浆蛋白;各处理组都补充蛋氨酸和赖氨酸。将360尾初始体重为(7.28±0.10) g的卵形鲳鲹幼鱼随机分配到12个海上网箱中,每个网箱30尾鱼,每种饲料设3个网箱。将鱼以上述4种饲料饲养62 d后,测定其生长性能、体组成、血清生化指标、肠道消化酶活性与组织抗氧化指标。结果显示,各实验组鱼的增重率(WGR)、特定生长率(SGR)、蛋白质效率(PER)、饲料系数(FC)、胃蛋白酶(PEP)、脂肪酶(LPS)和淀粉酶(AMS)活性均无显著差异(P > 0.05)。D3和D4组全鱼粗蛋白含量显著高于D1和D2组,D4组鱼肌肉脂肪含量显著低于D1~D3组(P < 0.05);D2~D4组鱼血清谷草转氨酶(AST)及D2和D3组鱼谷丙转氨酶(ALT)活性都显著低于D1组(P < 0.05),D1和D4组血清总蛋白(TP)和球蛋白(GLO)水平显著高于D2和D3组(P < 0.05);D2~D4组肝脏过氧化氢酶(CAT)活性、总抗氧化能力(T-AOC)和肌肉超氧化物歧化酶(SOD)活性显著高于D1组(P < 0.05),且肝脏丙二醛(MDA)含量低于D1组(P < 0.05)。研究表明,含6%鱼粉的D4组鱼的生长性能与30%鱼粉D1组无差异,且全鱼蛋白含量及肝脏和肌肉抗氧化能力显著提高,说明14%陆生复合蛋白配合10%酶解鱼浆蛋白可有效替代卵形鲳鲹饲料中80%鱼粉,使饲料鱼粉使用量低至6%。本研究是首次探讨酶解鱼浆蛋白在卵形鲳鲹配合饲料中应用的可行性,结果可为研发高效低成本配合饲料提供参考依据。
关键词卵形鲳鲹    鱼粉替代    酶解鱼浆    生长性能    抗氧化指标    
Replacing Fishmeal with Fish Protein Hydrolysate and Terrestrial Complex Protein in the Compound Feed of Trachinotus ovatus
LI Hengji 1,2#, XU Chao 1#, SU Zeliang 1, ZHANG Guanrong 1, MA Rongcai 1, ZHENG Jun 1, AN Wenqiang 1, CHEN Yuhang 2, LI Yuanyou 1     
1. College of Marine Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China;
2. Guangdong Daynew Aquatic Sci-Tech Co., Ltd., Foshan, Guangdong 528300, China
Abstract: Golden pompano Trachinotus ovatus is one of the most commercially important carnivorous marine species cultured in China. In recent years, the large-scale development of the aquaculture industry of T. ovatus has been rapid because of its fast growth rate and high flesh quality, and annual output has exceeded 100 000 tons. Currently, commercial formula feed for this fish still contains over 20%~30% of fishmeal (FM), the use of which precludes a sustainable aquaculture industry. As an alternative protein source, terrestrial compound proteins, which are a combination of several easily available and relatively low-priced terrestrial animal proteins and enzymatic hydrolysis or fermentation of terrestrial plant protein in a certain proportion, can alleviate the amino acid imbalance caused by a single alternative source. Terrestrial compound proteins are known to reduce the use of FM in marine carnivorous fish diets. In addition, fish protein hydrolysate is a new protein source that is processed from fish catches. In contrast to fish meal, it has an essential enzymatic hydrolysis step in the production process, so it contains more oligopeptides and free amino acids, which has been widely concerned in the industry. However, there are no reports on the application of fish protein hydrolysate in the feed of golden pompano. In order to decrease the use of FM in T. ovatus diets and evaluate the feasibility of substitution by terrestrial compound proteins and fish protein hydrolysate, this study was conducted to investigate the effects of replacing FM with compound protein and fish protein hydrolysate on growth performance, serum biochemical indexes, digestive enzyme activity, and tissue antioxidant capacity of T. ovatus. Four diets containing 42% crude protein and 12% crude fat were formulated, including D1 (control group), containing 30% fish meal; D2~D4 containing 14% terrestrial compound protein, 16%, 11%, and 6% fish meal, and 0%, 5%, and 10% fish protein hydrolysate, respectively. Methionine and lysine were added to the D2~D4 groups. T. ovatus juveniles (approximately 4 g mean initial weight) were bought from a local fish farm and then maintained for 2 months in two sea cages (2.0 m × 2.0 m × 2.0 m) at the coast near Nanao Marine Biology Station of Shantou University. A total of 360 fish (average body weight: [(7.28±0.10)g] were randomly distributed into 12 cages (1.0 m × 1.0 m × 1.5 m) and fed one of the four diets for 62 d. During the 62-d feeding trial, fish were fed to apparent satiation twice daily at 6:00 and 17:00, and the seawater temperature was 26.9℃~33.3℃, salinity was 27~33. The dead fish were collected over time and the day of death recorded. There were no significant differences in weight gain rate, specific growth rate, protein efficiency rate, feed conversion, feed rate, hepatosomatic index, viscerosomatic index, and condition factor, as well as pepsin, lipase, and amylase activity among all treatment groups (P > 0.05). The whole-body protein content of groups D3 and D4 was significantly higher than those of groups D1 and D2 (P < 0.05), and muscle fat content of groups D1~D3 was significantly higher than that of group D4 (P < 0.05). The activity rate of aspartate aminotransferase in groups D2~D4 and alanine aminotransferase in groups D2 and D3 were significantly lower than those in group D1 (P < 0.05). Total protein and globulin levels of groups D1 and D4 were significantly higher than those of groups D2 and D3 (P < 0.05). Liver catalase activity, total antioxidant capacity, and muscle superoxide dismutase activity of groups D2~D4 were significantly higher than those of group D1 (P < 0.05), but liver malondialdehyde content in groups D2~D4 was lower than that of group D1 (P < 0.05). Overall, the whole-body protein content and tissue (liver and muscle) antioxidant capacity of group D4 were significantly higher than those of other groups, and no significant differences in growth performance were found between groups D4 and D1. The use of fish protein hydrolysate increased the level of protein metabolism and immune function of the fish and reduced the degree of liver cell damage. The results indicate that 14% terrestrial compound protein combined with 10% fish protein hydrolysate can effectively replace 80% fish meal in the diet of golden pompano when the amount of fish meal is reduced to 6%. This study is the first to investigate the feasibility of the application of fish protein hydrolysate in the formula feed of golden pompano, and the results will be relevant to the research for high-quality and inexpensive protein sources in the artificial formula feed of juvenile golden pompano.
Key words: Trachinotus ovatus    Fish meal replacement    Fish protein hydrolysate    Growth performance    Antioxidant enzyme activity    

鱼粉因其蛋白含量高、氨基酸组分较平衡等优点而在水产饲料行业备受青睐。然而,随着水产养殖业的迅猛发展,饲料需求量骤增而带来的鱼粉短缺、价格上涨问题日益凸显。为解决这一问题,寻找适宜的鱼粉替代蛋白源已成为当务之急。目前,已有大量关于单一动植物蛋白源替代鱼粉的研究,且在开发新型饲料蛋白源、降低生产成本和保护环境等方面初见成效(易新文等, 2019; 胡海滨等, 2019; Chen et al, 2021; He et al, 2021)。但对于多数肉食或杂食性鱼类来说,单一蛋白源替代鱼粉的比例一般不超过50%,替代率过高容易导致生长性能和营养品质下降(周晖等, 2012; 王婧瑶等, 2021; 潘世会等, 2020)。因此,利用不同类型蛋白源互补组合,提高其在水产配合饲料中的利用率,已成为提高鱼粉替代比例的重要途径(林一帆等, 2019; 朱旺明等, 2019; 胡鹏莉等, 2019; Ma et al, 2020)。酶解鱼浆蛋白是一种由渔获物加工而成的新型蛋白源,鱼粉不同的是在其生产过程中有一道酶解步骤,因此,其含有较多寡肽、游离氨基酸及一些鱼粉所没有的促生长因子而被业界广泛关注(周露阳等, 2019吴代武等, 2015Shi et al, 2019Halim et al, 2016)。在黄颡鱼(Pelteobagrus fulvidraco)(吴代武等, 2018)、银鲳鱼(Trachinotus blochii)(Tejpal et al, 2021)和大菱鲆(Scophthalmus maximus)(Wei et al, 2020)等品种中的研究表明,酶解鱼浆蛋白可有效替代饲料中的鱼粉,不仅对鱼体生长无负面影响,还会显著提高其免疫力和抗氧化力。同时,酶解鱼浆蛋白也被认为是一种功能性添加剂,具有提高水产动物蛋白利用率的效果(Egerton et al, 2020; Wei et al, 2019)。然而,它在卵形鲳鲹上的应用研究尚未见报道。

卵形鲳鲹(Trachinotus ovatus)俗称金鲳,是我国主要的海水养殖品种之一,属于肉食鱼类,具有生长速度快、产量高、肉味鲜美的特点(李远友等, 2019; Wang et al, 2017)。本课题组近年的研究表明,以几种陆生动植物蛋白按一定比例配制的复合蛋白可替代其配合饲料中80%鱼粉(Ma et al, 2020)。基于此,本研究利用该复合蛋白与酶解鱼浆蛋白搭配来替代卵形鲳鲹幼鱼配合饲料中不同水平的鱼粉,通过生长性能、体组成、血清生化指标、消化酶活性及抗氧化能力的比较,评估替代可行性,获得适宜替代比例。所获结果将为卵形鲳鲹低鱼粉配合饲料开发提供理论依据。

1 材料与方法 1.1 实验饲料

以鱼粉、复合蛋白和酶解鱼浆蛋白为主要蛋白源,以鱼油、亚麻籽油、豆油、磷脂油等按一定比例配制的金鲳复合油为脂肪源,制备4种等蛋(42%)等脂(12%)配合饲料(D1~D4),其中,D1(对照组)含30%鱼粉,D2~D4分别含16%、11%和6%鱼粉及0、5%、10%酶解鱼浆蛋白,饲料配方见表 1。此外,各组饲料氨基酸和脂肪酸组成分别见表 2表 3

表 1 饲料组成和营养水平(%干物质) Tab.1 Feed formulation and nutrient component (% dry matter)
表 2 实验饲料的氨基酸组成(%) Tab.2 Amino acid composition of the experimental diets (%)
表 3 实验饲料的脂肪酸组成(%总脂肪酸) Tab.3 Fatty acid composition of the experimental diets (% total fatty acids)
1.2 实验设计

实验所用卵形鲳鲹幼鱼购自福建某金鲳养殖场,用鱼船运至汕头大学南澳临海实验站后,以商品饲料暂养于实验站附近的海上网箱中14 d后,将大小基本一致的鱼按每个网箱40尾左右放养在12个实验网箱(1.0 m×1.0 m×1.5 m)中,以4种实验饲料等量混合进行小网箱中适应性养殖14 d,然后开始正式养殖实验。分组前,将鱼禁食24 h,挑选规格整齐、体格健康的幼鱼[初始均重为(7.28±0.10) g]集中到一个大网箱中,然后随机给每个网箱分配30尾并称重,每种饲料设3个重复网箱,养殖62 d。每天近饱食投喂2次(08:00和17:00),记录鱼死亡情况和投饵量;期间,水温为26.9~33.3℃,盐度为27~33。

1.3 实验鱼称重、采样

养殖实验结束时,将鱼停喂24 h后,对各网箱中的鱼称重并清点数量。从每个网箱随机取3尾鱼,用含0.01% 2-苯氧基乙醇的海水麻醉后,通过尾静脉取血。将采集到的血液移入1.5 mL离心管中,在4℃下静置2~4 h后于3000 r/min离心10 min (4℃);将上清液转移到新的离心管中后,放入液氮中速冻,然后置于–80℃保存,待测相应指标。此外,将取血后的鱼解剖,称肝脏重和内脏重;取适量肝脏、胃、小肠和肌肉样品放入离心管中,液氮中速冻后置于−80℃冰箱中保存备用。最后,从每网箱取2尾鱼用于全鱼营养成分测定。

1.4 计算公式及样品分析方法
$ \text {存活率(survival rate, SR, %) }=100 \times N_{f} / N_{i} \text {; } $
$ \text {增重率(weight gain rate, WGR, %)} =100 \times\left(W_{f}-\right. \left.W_{i}\right) / W_{i} ; $
$ \text {特定生长率(specific growth rate, SGR, %/d)} = 100×(\ln W_{f} –\ln W_{i})/t\text{;} $
$ \text {饲料系数(feed coefficient,FC)} = D_{a}/(W_{f} –W_{i})\text{;} $
$ \text {日摄食率(feed intake, FI, %/d)} = 100×D_{a}/[(W_{i}+W_{f})/ 2]/t\text{;} $
$ \text {蛋白质效率(protein efficiency ratio, PER, %)} = 100×(W_{f}–W_{i})/(D_{a}×P_{d})\text{;} $
$ {\text{肥满度(condition factor, CF) }}= 100×W_{b}/L_{b}^{3}\text{;} $
$ {\text{肝体比(hepatosomatic index, HSI, %)}} = 100×W_{l}/ W_{b}\text{;} $
$ {\text{脏体比(viscerosomatic index, VSI, %)}} = 100×W_{v}/ W_{b}。$

式中,NiNf分别为初始、终末鱼的数量;WiWf分别为初始、终末平均鱼体体重(g);WiWf分别为初始、终末鱼体总重(g);t为养殖天数(d);Da为总摄入饲量(干物质基础,g);Pd为饲料(干物质基础)的粗蛋白质含量(%);Wb为鱼体重(g);WlWv分别为肝脏、内脏团重量(g);Lb为鱼体长(cm)。

饲料和组织常规营养成分分析:水分采用常压干燥法测定,依照GT/T6435-2014;灰分采用马弗炉灼烧法测定,依照GB/T6438-2007;粗蛋白采用凯氏定氮法测定,依照GB/T6433-2006;粗脂肪采用索氏抽提法测定,依照GB/T6433-2006。

脂肪提取及脂肪酸组成分析:将待测样品干燥粉碎后,称取粉碎样品200 mg放入15 mL玻璃离心管中,加入6 mL氯仿∶甲醇(2∶1)溶液后充分混合,然后置于4℃中浸泡48 h,期间充分混匀几次;加入蒸馏水2.7 mL后混合,再于3000 r/min离心5 min;吸取下层脂肪到新的离心管中,45℃氮气吹干。向脂肪干品中加入0.5 mmol/L KOH-甲醇溶液2 mL,于65℃水浴皂化至油滴消失。冷却后加入2 mL 15% 三氟化硼甲醇液,在70℃水浴加热30 min后加入2 mL正己烷和2 mL饱和氯化钠溶液,充分混合后,于3000 r/min下离心5 min后,取上层样用气相色谱仪(Agilent 7890B GC)分析脂肪酸组成。

氨基酸组成测定:将待测样品干燥粉碎后,称取粉碎样品30 mg放入水解管中,加入6 mol/L盐酸10 mL,封住水解管管口,在110℃恒温下干燥水解22 h,取出冷却;打开水解管,将水溶液过滤,使用0.02 mol/L盐酸定容至50 mL。取0.1 mL定容液与0.9 mL 0.02 mol/L盐酸混匀,60℃水浴蒸干后加入1 mL 0.02 mol/L盐酸复溶,取样用全自动氨基酸分析仪(SYKAM S-433D)分析氨基酸组成。

生化指标测定:从–80℃冰箱取出血清样品放置冰上解冻溶化,根据试剂盒说明书要求测定相关指标;从–80℃冰箱取出肌肉、胃、小肠和肝脏样品后,取适量样品于研磨管中研磨,加入生理盐水或指定溶液,离心后取上层样根据试剂盒说明书要求测定相关指标。血清总蛋白(total protein, TP)、白蛋白(albumin, ALB)、甘油三酯(triglyceride, TG)、总胆固醇(total cholesterol, T-CHO)、尿素氮(blood urea nitrogen, BUN)、血氨(serum ammonia, SA)、谷草转氨酶(aspartate aminotransferase, AST)和谷丙转氨酶(alanine aminotransferase, ALT)含量,肝脏和肌肉总抗氧化能力(total antioxidant capacity, T-AOC)、还原性谷胱甘肽(reduced glutathione, GSH)含量、过氧化氢酶(catalase, CAT)活性、超氧化物歧化酶(superoxide dismutase, SOD)活性和丙二醛(malondialdehyde, MDA)含量,胃蛋白酶(pepsin, PEP)、脂肪酶(lipase, LPS)和淀粉酶(amylase, AMS)活性均采用南京建成生物技术研究所生产的试剂盒进行测定。

1.5 数据处理

结果以平均值±标准误(Mean±SE)表示。用SPSS 16.0对数据进行单因素方差分析(one-way ANOVA);数据差异显著时,采用Turkey′s多重检验法进行比较,P < 0.05时认为差异显著。

2 结果 2.1 各饲料投喂组鱼的生长性能与饲料利用情况比较

实验结束时,卵形鲳鲹幼鱼的生长性能与饲料利用指标见表 4。结果显示,各饲料投喂组鱼的生长性能指标,增重率(WGR)、特定生长率(SGR)、蛋白质效率(PER)、日摄食率(FI)、饲料系数(FC)、肝体比(HSI)和脏体比(VSI)相互间均无显著差异(P > 0.05)。

表 4 各饲料投喂组卵形鲳鲹的生长性能与饲料利用情况 Tab.4 Growth performance and feed utilization of T. ovatus fed different diets
2.2 各饲料投喂组全鱼与肌肉营养成分比较

各饲料投喂组全鱼及肌肉营养成分比较结果见表 5。各饲料组全鱼的水分和灰分、肌肉的水分、粗蛋白和灰分均无显著差异(P > 0.05)。但D3和D4组全鱼粗蛋白含量显著高于D1和D2组鱼(P < 0.05);D2组全鱼粗脂肪含量显著高于D4组鱼(P < 0.05),但与其他实验组鱼无显著差异(P > 0.05);D4组鱼肌肉粗脂肪含量显著低于其他实验组鱼(P < 0.05)。

表 5 各饲料投喂组卵形鲳鲹全鱼及肌肉的营养成分 Tab.5 Nutritional composition in whole fish and muscle of T. ovatus fed different diets
2.3 各饲料投喂组鱼血清生化指标的比较

表 6可知,血清总蛋白(TP)和球蛋白(GLO)含量随着鱼粉替代比例上升而显著增加(P < 0.05)。D1组鱼血清谷丙转氨酶(ALT)和谷草转氨酶(AST)显著高于D2和D3组鱼(P < 0.05),但其与D4组ALT无显著差异(P > 0.05)。各饲料组鱼血清白蛋白(ALB)、尿素氮(BUN)和血氨(SA)均无显著差异(P > 0.05)。

表 6 不同处理组饲料对卵形鲳鲹血清生化指标的影响 Tab.6 Serum biochemical parameters of T. ovatus fed different diets
2.4 各饲料投喂组鱼消化酶活性的比较

不同饲料投喂组鱼胃和肠的消化酶活性见表 7。各饲料组鱼胃蛋白酶(PEP)、脂肪酶(LPS)和淀粉酶(AMS)活性均无显著差异(P > 0.05)。

表 7 各饲料投喂组卵形鲳鲹的消化酶活性 Tab.7 The digestive enzyme activity of T. ovatus fed different diets
2.5 各饲料投喂组鱼肝脏与肌肉抗氧化指标的比较

图 1呈现各饲料投喂组鱼肝脏与肌肉抗氧化指标结果。D2~D4组鱼肝脏过氧化氢酶(CAT)活性和总抗氧化能力(T-AOC),肌肉超氧化物歧化酶(SOD)活性显著高于D1组(P < 0.05),而肝脏丙二醛(MDA)含量正好相反。此外,肝脏还原性谷胱甘肽(GSH)、肌肉CAT活性随着鱼粉替代比例升高而增加。肝脏SOD活性,肌肉GSH活性和丙二醛(MDA)含量各组间均无显著差异(P > 0.05)。

图 1 各饲料投喂组鱼肝脏(A)和肌肉(B)的抗氧化指标 Fig.1 The antioxidant index in liver (A) and muscle (B) of T. ovatus fed different diets 过氧化氢酶(CAT, U/mg prot);还原性谷胱甘肽(GSH, μmol/g prot);超氧化物歧化酶(SOD, U/mg prot);总抗氧化能力(T-AOC, mmol/g);丙二醛(MDA, nmol/mg prot)。数据为平均值±标准误(n=3),各指标柱上无相同小写字母标注者表示相互间有显著差异(P < 0.05)。 Catalase (CAT, U/mg prot); Reduced glutathione (GSH, μmol/g prot); Superoxide dismutase (SOD, U/mg prot); Total antioxidant capacity (T-AOC, mmol/g); Malondialdehyde (MDA, nmol/mg prot). Values are Mean±SE (n=3), for each index, columns without sharing a common superscript letter are significantly different (P < 0.05).
3 讨论 3.1 复合蛋白搭配酶解鱼浆蛋白可高比例替代鱼粉的原因分析

本研究中,各饲料投喂组鱼的增重率(WGR)、特定生长率(SGR)、蛋白质效率(PER)、饲料系数(FC)和日摄食率(FI)等指标无差异,说明复合蛋白搭配酶解鱼浆蛋白可有效替代配合饲料中80%鱼粉,使饲料鱼粉用量降低至6%。相似地,利用酶解鱼浆蛋白搭配植物蛋白可替代红鳍东方鲀(Takifugu rubripes)饲料中60%鱼粉(Wei et al, 2021)。在银鲳鱼中,随着酶解鱼浆蛋白替代鱼粉比例增加,生长性能和饲料利用都显著提高(Tejpal et al, 2021)。酶解鱼浆蛋白可以有效替代鱼粉的可能原因有:(1) 经酶解的鱼浆蛋白会含有更多易于消化吸收的蛋白质、小肽和游离氨基酸等营养物质(周露阳等, 2019; Hien et al, 2014; Juliano et al, 2019),饲料中小肽和游离氨基酸比例的改变将上调肠道小肽和氨基酸转运蛋白的基因表达水平,提高肠道对营养物质的吸收能力(Wu et al, 2018),从而缓解因鱼粉替代对鱼体生长造成的负面影响;(2)酶解鱼浆蛋白具有足量的精氨酸和亮氨酸,会促进雷帕霉素靶蛋白1 (mammalian target of rapamycin 1, mTOR1)的活化,从而有助于鱼体的生长(Robert et al, 2017)。

3.2 酶解鱼浆蛋白影响卵形鲳鲹全鱼和肌肉营养成分的原因探讨

全鱼和肌肉粗蛋白含量直接反映饲料中蛋白质在机体中的沉积情况(Hernández et al, 2021)。本研究中,全鱼和肌肉粗蛋白含量随鱼粉替代水平的增加呈现上升趋势,表明酶解鱼浆蛋白能够增加鱼体对饲料中蛋白质的沉积效率。这可能是由于酶解鱼浆蛋白中足量的精氨酸和亮氨酸会激活mTOR1,进而通过磷酸化使其下游靶蛋白核糖体S6蛋白激酶1 (ribosomal protein S6 kinase1, S6K1)及真核细胞始动因子4E结合蛋白1(eukaryotic initiation factor4E binding protein1, 4EBP1)激活,促进鱼体蛋白质的合成(Robert et al, 2017; Tang et al, 2013; Liang et al, 2016; Zhou et al, 2019)。与卵形鲳鲹结果不同的是,在红鳍东方鲀(Wei et al, 2021)、石斑鱼(Epinephelus fuscoguttatus) (Mamauag et al, 2017)和大菱鲆(Wei et al, 2016)的研究中,尽管酶解鱼浆蛋白替代饲料中的鱼粉会显著提高生长性能,但全鱼或肌肉的蛋白质含量都无显著变化,这可能与物种间对酶解鱼浆蛋白利用的差异所致。

3.3 酶解鱼浆蛋白影响卵形鲳鲹血清生化指标的原因探讨

血清总蛋白(TP)是血清中白蛋白(ALB)和球蛋白(GLO)之和。血清中TP含量可直接反映机体营养状态及蛋白质的吸收和代谢情况,其含量增加,表明蛋白质的合成代谢加强。GLO是机体内参与免疫反应的蛋白质,其含量增加,表明机体的抗体水平增加(杨宏波等, 2015; Yu et al, 2020; Mu et al, 2015; Marono et al, 2017)。此外,正常情况下,谷丙转氨酶(ALT)与谷草转氨酶(AST)大量存在于肝细胞中,当肝细胞受损时其会被释放到血清中,造成血清ALT和AST活性升高(陈晨等,2010)。本研究中,卵形鲳鲹血清总蛋白(TP)和球蛋白(GLO)含量随鱼粉被酶解鱼浆蛋白替代水平的增加呈上升趋势,而谷丙转氨酶(ALT)和谷草转氨酶(AST)活性降低,说明复合蛋白搭配酶解鱼浆蛋白能够增强卵形鲳鲹的蛋白代谢水平和免疫功能,同时降低肝细胞受损风险。在一些海洋肉食性鱼类的研究发现,饲料中添加酶解鱼浆蛋白可以有效增强银鲳鱼对鳗弧菌(Vibrio anguillarum) (Tejpal et al, 2021),尖吻鲈(Lates calcarifer)对海豚链球菌(Streptococcus iniae)(Siddik et al, 2018)和褐牙鲆(Paralichthys olivaceus)对爱德华氏菌(Edwardsiella tarda)(Khosravi et al, 2018)的抗菌力。以上结果提示,酶解鱼浆蛋白的使用可以增强养殖鱼类的抵抗力,更好地适应复杂的养殖环境,从而提高养殖效益。

3.4 复合蛋白配合酶解鱼浆蛋白对卵形鲳鲹消化酶活性无影响的原因探讨

鱼类的生长及饲料利用率与其肠道功能密切相关。其中,鱼类肠道酶的活性决定了其肠道的消化吸收功能,并能够直接反映鱼体获得和利用饲料营养成分的能力。本研究中,各替代组鱼体消化酶活性与鱼粉组鱼无显著差异,提示复合蛋白配合酶解鱼浆替代饲料中鱼粉未对金鲳消化功能产生负面影响。其与黄金鲫(Carassius auratus)中的研究结果相反,即利用豆粕替代饲料中34%鱼粉时,肠道蛋白酶活性显著下降(王婧瑶等, 2021)。这可能是由于豆粕中存在的抗营养因子损伤消化道黏膜结构,进而降低肠腺体分泌消化酶的功能(Fuertes et al, 2013)。此外,抗营养因子会与消化酶形成稳定的化合物,使其失去酶解能力,导致酶活性被抑制(徐奇友等, 2006)。本研究所用的复合蛋白是一种酶解植物蛋白和动物蛋白按一定比例配合后的产品(Ma et al, 2020),其抗营养因子被有效降解,从而替代饲料中鱼粉未对鱼体消化功能产生负面影响。

3.5 不同处理组饲料影响卵形鲳鲹肝脏和肌肉抗氧化指标的原因探讨

生物有机体在氧化代谢过程中不断产生自由基,具有强氧化性,机体对自由基的清除主要依赖于机体完整的抗氧化防御系统的预防性或阻断性控制,从而保护机体组织和细胞免受自由基的氧化损伤(Su et al, 2018; Zhao et al, 2017、2020)。本研究中,鱼粉替代组肝脏过氧化氢酶(CAT)活性和总抗氧化能力(T-AOC),肌肉超氧化物歧化酶(SOD)活性和总抗氧化能力(T-AOC)显著高于D1组。此外,肝脏GSH、肌肉CAT活性随着鱼粉替代比例上升而显著增加,而肝脏和肌肉丙二醛(MDA)含量变化趋势与之相反。这些结果表明,复合蛋白搭配酶解鱼浆蛋白替代鱼粉能够增强卵形鲳鲹肝脏和肌肉组织的抗氧化能力。这可能由于复合蛋白中含一定量的植物蛋白,其富含的维生素E、槲皮素和姜黄素具有增加抗氧化能力的作用(Mahmoud et al, 2017; Qiang et al, 2019)。此外,机体抗氧化能力与饲料中n-3 PUFA含量密切相关,一方面,n-3 PUFA作为一种高不饱和脂肪酸,自身极易被氧化,机体会增强内生抗氧化系统来抵御这种情况,这是一种负反馈现象;另一方面,n-3 PUFA的生理作用直接增加了人体抗氧化系统成分的活力(Li et al, 2020; Freneau et al, 2001)。因此,饲料中增加的n-3 PUFA会显著促进机体抗氧化能力,但本实验D1组饲料n-3 PUFA含量为最高,抗氧化值则最低,这可能与复合蛋白的使用有关,具体原因有待进一步研究。

4 结论

综上,本研究利用复合蛋白配合酶解鱼浆蛋白替代卵形鲳鲹饲料中80%鱼粉后,其生长性能与30%鱼粉组一样,且全鱼蛋白含量、肝脏和肌肉抗氧化能力增加,说明80%鱼粉替代水平可行,使饲料中鱼粉用量降低至6%。研究结果为研发高效低鱼粉卵形鲳鲹配合饲料提供了参考依据。

参考文献
CHEN C, HUANG F, SHU Q Y, et al. Effects of dietary conjugated linoleic acid on growth performance, muscle composition, AST and ALT activities in serum in juveniles grass carp (Ctenopharyngodon idellus). Acta Hydrobiologica Sinica, 2010, 34(3): 647-651 [陈晨, 黄峰, 舒秋艳, 等. 共轭亚油酸对草鱼生长、肌肉成分、谷草转氨酶及谷丙转氨酶活性的影响. 水生生物学报, 2010, 34(3): 647-651]
CHEN Y K, CHI S Y, ZHANG S, et al. Replacement of fish meal with Methanotroph (Methylococcus capsulatus, Bath) bacteria meal in the diets of Pacific white shrimp (Litopenaeus vannamei). Aquaculture, 2021, 541: 736801 DOI:10.1016/j.aquaculture.2021.736801
EGERTON S, WAN A, MURPHY K, et al. Replacing fishmeal with plant protein in Atlantic salmon (Salmo salar) diets by supplementation with fish protein hydrolysate. Scientific Reports, 2020, 10(1): 13-39 DOI:10.1038/s41598-019-55911-3
FRENEAU J M, PROST E D, BELLEVILLE J L, et al. A polyunsaturated fatty acid diet lowers blood pressure and improves antioxidant status in spontaneously hypertensive rats. Journal of Nutrition, 2001, 131(1): 39-45 DOI:10.1093/jn/131.1.39
FUERTES J B, CELADA J D, CARRAL J M, et al. Replacement of fish meal with poultry by-product meal in practical diets for juvenile crayfish (Pacifastacus leniusculus Dana, Astacidae) from the onset of exogenous feeding. Aquaculture, 2013, 404-405
HALIM N R A, YUSOF H M, SARBON N M. Functional and bioactive properties of fish protein hydolysates and peptides: A comprehensive review. Trends in Food Science and Technology, 2016, 51: 24-33 DOI:10.1016/j.tifs.2016.02.007
HE Y F, GUO X W, TAN B P, et al. Replacing fish meal with fermented rice protein in diets for hybrid groupers (Epinephelus fuscoguttatus ♀× Epinephelus lanceolatus ♂): Effects on growth, digestive and absorption capacities, inflammatory-related gene expression, and intestinal microbiota. Aquaculture Reports, 2021, 19: 100603 DOI:10.1016/j.aqrep.2021.100603
HIEN T D B, SANAZ K, VINCENT F, et al. Growth performance, feed utilization, innate immunity, digestibility and disease resistance of juvenile red seabream (Pagrus major) fed diets supplemented with protein hydrolysates. Aquaculture, 2014, 418–419: 11-19
HU H B, XIE S Q, QIAN X Q, et al. Effects of dietary corn gluten meal or poultry meal partially replacing fish meal on growth performance of pompano ovatus Trachinotus ovatus. Chinese Journal of Animal Nutrition, 2019, 31(6): 2752-2764 [胡海滨, 解绶启, 钱雪桥, 等. 饲料中添加玉米蛋白粉或鸡肉粉替代部分鱼粉对卵形鲳鲹生长性能的影响. 动物营养学报, 2019, 31(6): 2752-2764]
HU P L, WU R, LU K L, et al. Effects of replacing fish meal with composite protein on growth, diet digestibility, and gut health in Japanese seabass (Lateolabrax maculatus). Progress in Fishery Sciences, 2019, 40(6): 56-65 [胡鹏莉, 吴瑞, 鲁康乐, 等. 复合蛋白替代鱼粉对花鲈生长、消化能力和肠道健康的影响. 渔业科学进展, 2019, 40(6): 56-65]
JULIANO U, EDUARDO K B, RAFAEL L, et al. Tilapia protein hydrolyzate improves growth performance, protein absorption and antioxidant status in silver catfish (Rhamdia quelen). Aquaculture Research, 2019, 50(11): 3192-3201 DOI:10.1111/are.14273
KHOSRAVI S, BUI H T D, HERAULT M, et al. Supplementation of protein hydrolysates to a low-fishmeal diet improves growth and health status of juvenile olive flounder, Paralichthys olivaceus. Journal of the World Aquaculture Society, 2018, 49(5): 897-911 DOI:10.1111/jwas.12436
LI M M, ZHANG M, MA Y C, et al. Dietary supplementation with n-3 high unsaturated fatty acids decreases serum lipid levels and improves flesh quality in the marine teleost golden pompano Trachinotus ovatus. Aquaculture, 2020, 516: 734632 DOI:10.1016/j.aquaculture.2019.734632
LI Y Y, LI M M, WANG M, et al. Research advances in nutritional requirement and feed of Trachinotus ovatus. Progress in Fishery Sciences, 2019, 40(1): 167-177 [李远友, 李孟孟, 汪萌, 等. 卵形鲳鲹营养需求与饲料研究进展. 渔业科学进展, 2019, 40(1): 167-177]
LIANG H L, REN M C, HABTE-TSION H M, et al. Dietary arginine affects growth performance, plasma amino acid contents and gene expressions of the TOR signaling pathway in juvenile blunt snout bream, Megalobrama amblycephala. Aquaculture, 2016, 461: 1-8 DOI:10.1016/j.aquaculture.2016.04.009
LIN Y F, SHAO X P, JIN Y, et al. Effects of fish meal replacement by animal and plant protein mixture on morphology indexes, tissue fatty acid composition, serum biochemical indexes and hepatic histology of juvenile black carp (Mylopharyngodon piceus). Chinese Journal of Animal Nutrition, 2019, 31(2): 732-745 [林一帆, 邵仙萍, 金燕, 等. 复合动植物蛋白质源替代鱼粉对青鱼幼鱼形体指标、组织脂肪酸组成、血清生化指标及肝脏组织形态的影响. 动物营养学报, 2019, 31(2): 732-745 DOI:10.3969/j.issn.1006-267x.2019.02.030]
MA Y C, LI M M, XIE D Z, et al. Fishmeal can be replaced with a high proportion of terrestrial protein in the diet of the carnivorous marine teleost (Trachinotus ovatus). Aquaculture, 2020, 519: 734910 DOI:10.1016/j.aquaculture.2019.734910
MAHMOUD H K, AL-SAGHEER A A, REDA F M, et al. Dietary curcumin supplement influence on growth, immunity, antioxidant status, and resistance to Aeromonas hydrophila in Oreochromis niloticus. Aquaculture, 2017, 475: 16-23 DOI:10.1016/j.aquaculture.2017.03.043
MAMAUAG R E P, RAGAZA J A. Growth and feed performance, digestibility and acute stress response of juvenile grouper (Epinephelus fuscoguttatus) fed diets with hydrolysate from milkfish offal. Aquaculture Research, 2017, 48(4): 1638-1647 DOI:10.1111/are.12999
MARONO S, LOPONTE R, LOMBARDI P, et al. Productive performance and blood profiles of laying hens fed Hermetia illucens larvae meal as total replacement of soybean meal from 24 to 45 weeks of age. Poultry Science, 2017, 96(6): 1783-1790 DOI:10.3382/ps/pew461
MU C L, YANG Y X, LUO Z, et al. Metabolomic analysis reveals distinct profiles in the plasma and urine of rats fed a high-protein diet. Amino Acids, 2015, 47(6): 122-1238
PAN S H, LI Q, ZHANG Y T, et al. Effects of replacing fish meal with poultry meat and bone meal on growth digestion and antioxidant capacity of turbot. Rural Science and Technology, 2020, 11(22): 112-115 [潘世会, 李庆, 张钰婷, 等. 禽肉骨粉替代鱼粉对大菱鲆生长、消化和抗氧化力的影响. 乡村科技, 2020, 11(22): 112-115 DOI:10.3969/j.issn.1674-7909.2020.22.058]
QIANG J, WASIPE A, HE J, et al. Dietary vitamin E deficiency inhibits fat metabolism, antioxidant capacity, and immune regulation of inflammatory response in genetically improved farmed tilapia (Oreochromis niloticus) fingerlings following Streptococcus iniae infection. Fish and Shellfish Immunology, 2019, 92: 395-404 DOI:10.1016/j.fsi.2019.06.026
ROBERT A S, DAVID M S. mTOR signaling in growth, metabolism, and disease. Cell, 2017, 168(6): 960-976 DOI:10.1016/j.cell.2017.02.004
SHI Y, ZHONG L, MA X K, et al. Effect of replacing fishmeal with stickwater hydrolysate on the growth, serum biochemical indexes, immune indexes, intestinal histology and microbiota of rice field eel (Monopterus albus). Aquaculture Reports, 2019, 15: 100223 DOI:10.1016/j.aqrep.2019.100223
SIDDIK M A, HOWIESON J, PARTRIDGE G J, et al. Dietary tuna hydrolysate modulates growth performance, immune response, intestinal morphology and resistance to Streptococcus iniae in juvenile barramundi, Lates calcarifer. Scientific Reports, 2018, 8(1): 15942 DOI:10.1038/s41598-018-34182-4
SU Y N, WU P, FENG L, et al. The improved growth performance and enhanced immune function by DL-methionyl-DL-methionine are associated with NF-κB and TOR signalling in intestine of juvenile grass carp (Ctenopharyngodon idella). Fish and Shellfish Immunology, 2018, 74: 101-118 DOI:10.1016/j.fsi.2017.12.051
TANG L, FENG L, SUN C Y, et al. Effect of tryptophan on growth, intestinal enzyme activities and TOR gene expression in juvenile Jian carp (Cyprinus carpio var. Jian): Studies in vivo and in vitro. Aquaculture, 2013, 412/413: 23-33
TEJPAL C S, VIJAYAGOPAL P, ELAVARASAN K, et al. Evaluation of pepsin derived tilapia fish waste protein hydrolysate as a feed ingredient for silver pompano (Trachinotus blochii) fingerlings: Influence on growth, metabolism, immune and disease resistance. Animal Feed Science and Technology, 2021, 272: 114748 DOI:10.1016/j.anifeedsci.2020.114748
WANG J Y, WU L F, WANG D, et al. Effects of soybean meal instead of fish meal on growth, digestive enzyme activity and non-specific immune indexes of Carassius auratus. Journal of Jilin Agricultural University, 2022, 42(1): 104-111 [王婧瑶, 吴莉芳, 王东, 等. 豆粕替代鱼粉对黄金鲫生长、消化酶活力及非特异性免疫指标的影响. 吉林农业大学学报, 2022, 42(1): 104-111]
WANG Y, MA X Z, WANG F, et al. Supplementations of poultry by-product meal and selenium yeast increase fish meal replacement by soybean meal in golden pompano (Trachinotus ovatus) diet. Aquaculture Research, 2017, 48(4): 1904-1914 DOI:10.1111/are.13028
WEI Y L, LIANG M Q, XU H G, et al. Fish protein hydrolysate affected amino acid absorption and related gene expressions of IGF-1/AKT pathways in turbot (Scophthalmus maximus). Aquaculture Nutrition, 2020, 26(1): 145-155 DOI:10.1111/anu.12976
WEI Y L, LIANG M Q, XU H G, et al. Taurine alone or in combination with fish protein hydrolysate affects growth performance, taurine transport and metabolism in juvenile turbot (Scophthalmus maximus L. ). Aquaculture Nutrition, 2019, 25(2): 396-405 DOI:10.1111/anu.12865
WEI Y L, WANG J, ZHANG X, et al. Fish protein hydrolysate supplementation in plant protein based diets for tiger puffer (Takifugu rubripes) is an effective strategy of fish meal sparing. Aquaculture Reports, 2021, 20: 100720 DOI:10.1016/j.aqrep.2021.100720
WEI Y, LIANG M, MU Y, et al. The effect of ultrafiltered fish protein hydrolysate level on growth performance, protein digestibility and mRNA expression of PepT1 in juvenile turbot (Scophthalmus maximus). Aquaculture Nutrition, 2016, 22(5): 1006-1017 DOI:10.1111/anu.12319
WU D W, HE J, WANG B, et al. Effects of anchovy meal, tuna, cod steak fish meals and anchovy hydrolysate on growth serum biochemical parameters and the surface structure of gastric mucous in yellow catfish (Pelteobagrus fulvidraco). China Feed, 2018(1): 63-68 [吴代武, 何杰, 汪冰, 等. 鳀鱼粉、金枪鱼粉、鳕鱼排粉和酶解鳀鱼浆对黄颡鱼生长及健康的影响. 中国饲料, 2018(1): 63-68]
WU D W, SHUI D Z, CAI C F, et al. Nutrition changes associated with anchovy enzymolysis process. Feed Industry, 2015, 36(24): 25-30 [吴代武, 税典章, 蔡春芳, 等. 鳀鱼鱼浆的酶解过程与营养成分的变化. 饲料工业, 2015, 36(24): 25-30]
WU D W, ZHOU L Y, GAO M M, et al. Effects of stickwater hydrolysates on growth performance for yellow catfish (Pelteobagrus fulvidraco). Aquaculture, 2018, 488: 161-173 DOI:10.1016/j.aquaculture.2018.01.031
XU Q Y, XU H, MA J Z. Study progress on nutritional and annutritional factors in soy. China Oils and Fats, 2006(11): 17-20 [徐奇友, 许红, 马建章. 大豆中营养因子和抗营养因子研究进展. 中国油脂, 2006(11): 17-20 DOI:10.3321/j.issn:1003-7969.2006.11.003]
YANG H B, LIU H, YU T S, et al. Effects of different cysteamine hydrochlorie supplement on milk production and serum biochemical indicators of lactating dairy cows. Journal of China Agricultural University, 2015, 20(5): 201-208 [杨宏波, 刘红, 余同水, 等. 不同添加水平半胱胺对奶牛泌乳性能和血清生化指标的影响. 中国农业大学学报, 2015, 20(5): 201-208]
YI X W, CHEN R A, XU J H. Effects of the poulty by-product meal replacing partially dietary fishmeal on the growth, feed utilization and antioxidant activity of pompano ovatus Trachinotus ovatus. Journal of Ocean University of China (Natural Science), 2019, 49(12): 17-24 [易新文, 陈瑞爱, 徐家华. 鸡肉粉替代鱼粉对卵形鲳鲹生长、饲料利用和抗氧化力的影响. 中国海洋大学学报(自然科学版), 2019, 49(12): 17-24]
YU M, LI Z M, CHEN W D, et al. Evaluation of full-fat Hermetia illucens larvae meal as a fishmeal replacement for weaning piglets: Effects on the growth performance, apparent nutrient digestibility, blood parameters and gut morphology. Animal Feed Science and Technology, 2020, 264: 114431 DOI:10.1016/j.anifeedsci.2020.114431
ZHAO W, FANG H H, GAO B Y, et al. Dietary Tribonema sp. supplementation increased growth performance, antioxidant capacity, immunity and improved hepatic health in golden pompano (Trachinotus ovatus). Aquaculture, 2020, 529: 735667
ZHAO W, WANG L, LIU M, et al. Transcriptome, antioxidant enzyme activity and histopathology analysis of hepatopancreas from the white shrimp Litopenaeus vannamei fed with aflatoxin B1(AFB1). Developmental and Comparative Immunology, 2017, 74: 69-81 DOI:10.1016/j.dci.2017.03.031
ZHOU H, CHEN G, LIN X T. Effects of partial replacing of fish meal by three types of protein sources on growth performance and approximate compositions of juvenile cobia (Rachycentron canadum). Fisheries Science, 2012, 31(6): 311-315 [周晖, 陈刚, 林小涛. 三种蛋白源部分替代鱼粉对军曹鱼幼鱼生长和体成分的影响. 水产科学, 2012, 31(6): 311-315 DOI:10.3969/j.issn.1003-1111.2012.06.001]
ZHOU L Y, WU D W, GAO M M, et al. The effects of fish meal replacement on growth performance of yellow catfish (Pelteobagrus fulvidraco). Acta Hydrobiologica Sinica, 2019, 43(3): 504-516 [周露阳, 吴代武, 高敏敏, 等. 鱼溶浆、酶解鱼溶浆和酶解鱼浆完全替代鱼粉对黄颡鱼生长的影响. 水生生物学报, 2019, 43(3): 504-516]
ZHOU Z Y, WANG X, WU X Y, et al. Effects of dietary leucine levels on growth, feed utilization, neuro-endocrine growth axis and TOR-related signaling genes expression of juvenile hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂). Aquaculture, 2019, 504: 172-181
ZHU W M, LAN H B, TAN Y G, et al. Effects of replacing of fish meal with compound proteins on the growth performance, body composition and liver biochemical indices of largemouth bass (Micropterus salmoides). Feed Industry, 2019, 40(16): 35-42 [朱旺明, 蓝汉冰, 谭永刚, 等. 不同水平复合蛋白源等量替代鱼粉对大口黑鲈生长性能、体成分组成以及肝脏生化指标的影响. 饲料工业, 2019, 40(16): 35-42]