日粮不同粗纤维水平对幼兔生长发育的影响研究

以120只40日龄的新西兰兔为试验材料,随机分为A、B、C和D共4组。在其它营养水平相同的情况下,研究粗纤维水平分别为10%、11%、12%和13%的4种日粮对幼兔日增重、料肉比、腹泻率、经济效益等指标的影响。结果表明,试验期平均日增重以A组最高(27.78±3.85)g,且随着粗纤维水平的增加而逐渐减少(P<0.05);A组和D组分别具有最低(3.81)和最高料肉比(4.26),差异达到显著水平(P<0.05);随着粗纤维水平的逐渐增加,腹泻率呈显著下降趋势,粗纤维水平为10%时腹泻率达到26.67%;经济效益分析发现,C组的产出投入比最高。     

复合抗生素对断奶仔猪生产性能的影响

本试验采用对比试验,选择断奶仔猪50只,随机分成2组,即对照组和试验组。每组设5个重复,每个重复5只断奶仔猪,试验期28d。试验组在基础饲粮中添加硫酸新霉素(44mg/kg)和金霉素(100mg/kg)。试验结果表明在添加硫酸新霉素和金霉素显著提高了断奶仔猪日增重,日采食量,降低了料肉比,有效减少了仔猪腹泻。     

日粮中不同糖肽酮萜素水平对肉鸡生长性能的影响

选1日龄Avian肉仔鸡800羽,随机分成4组(每组4个重复,每个重复50羽)进行饲养试验。对照组喂基础日粮(无任何添加剂),各处理组饲粮在基础饲粮中0.25、0.5、0.75g/kg糖肽酮萜素。试验期为49d。试验结果表明:无论对于肉仔公鸡还是母鸡,无论在哪个生长阶段,各试验组的日增重均比对照组有显著提高,料肉比均显著降低。其中以0.5g/kg糖肽酮萜素添加水平促生长效果最好。     

肉仔鸡日粮的磷水平等

目前1g无机磷的价格远远超过了1g优质蛋白质,因此在日粮配方时,往往降低了可利用磷的水平.为深入了解低磷日粮的 影响,卢菁、冯定远等设计了一个不使用磷酸氢钙的配方,其总磷水平只相当于对照日粮的有效磷水平,观察其对肉仔鸡的影 响.共分4个处理:1组颗粒料对照组、2组颗粒料低磷组,3组粉料对照组、4组为粉料低磷组.结果:1、2、3、4组日增重分别为 15.74g/d、13.23g/d、15.19g/d、13.31g/d,料肉比分别为1.983、2.285、2.057、2.399,表明日粮中总磷水平偏低时,将降低肉仔鸡 的增重水平,低磷日粮中总磷水平与正常磷日粮中有效磷水平相同时,1～31日龄肉仔鸡的增重水平下降14.17%;同样饲粮转化 率平均下降13.74%.试验提示日粮中磷水平偏低是限制肉仔鸡生长的重要因素之一,生产中一定要注意有机磷的补充. <广东饲料>,2000(6):15～16 生长猪用抗生素的选择 山东省旺达饲料公司韩绍忠、牛如广等选用网床培育的杜长大三元生长猪48头,随机分成4个组,分别饲喂基础日粮+ 60mg/kg金霉素、基础日粮+50mg/kg杆菌肽锌、基础日粮+50mg/kg喹乙醇及不加任何药物添加剂的基础日粮(消化能13.39MJ/ kg、粗蛋白16.59%).结果表明:添加60mg/kg金霉素组生长猪的平均日增重最高、饲料转化率也最高,效果最为理想;50mg/ kg杆菌肽锌组虽然也达到了较高的日增重,但其饲料转化率却没有得到显著提高;50mg/kg喹乙醇组没有观察到促生长作 用.平均日采食量以添加50mg/kg杆菌肽锌组最高,50mg/kg喹乙醇组最低;各试验组腹泻疾病较少,未加抗生素组略多.表 明日粮中添加60mg/kg金霉素对生长猪的生长性能有促进作用,50mg/kg杆菌肽锌可提高日增重,而添加50mg/kg喹乙醇 对生长猪无明显促生长作用. <饲料搏览>,2000(10):36～37 肉鸭日粮中铬的补充 四川畜牧兽医学院刘安芳,肖文川等为探讨铬(吡啶羧酸铬)对肉鸭生长性能、屠宰指标和血清胆固醇含量的影响,选用1 日龄樱桃谷肉鸭500只,随机分为5个组(4个试验组+1个对照组),每组4个重复,每个重复25只.试验采用单因素完全随机 设计.A组为对照组,喂以基础日粮(0～3周龄ME12.12MJ/kg、CP22%,3～6周龄ME12.28MJ/kg,CP17.69%).B、C、D、E组为试 验组,分别在基础日粮中添加0.1mg/kg、0.2mg/kg、、0.3mg/kg和0.4mg/kg吡啶羧酸铬(以铬计),试验期42d.结果表明:试 验组肉鸭的腹脂率和胸肌率极显著优于对照组(P＜0.01),血中胆固醇含量显著低于对照组(P＜0.05),而生产性能和屠宰率与对 照组之间差异不显著(P＞0.05).提示吡啶羧酸铬对肉鸭生产性能无显著影响,但能极显著降低肉鸭腹脂率,提高胸肌率,而以日 粮中添加0.2mg/kg的效果最好. <饲料工业>,2000(12):16～18 早期断奶仔猪日粮添加肉碱的效应研究 中国农业大学动物科技学院朴香淑、李德发等用21日龄平均体重为5.85kg的断奶仔猪64头,随机分成4组,肉碱添加水平 分别为0、50mg/kg、100mg/kg和150mg/kg.结果表明:添加肉碱不影响仔猪的平均日增重和饲料转化率,但添加100mg/kg肉 碱可显著提高早期断奶仔猪的平均日采食量;各组干物质、粗灰分、粗蛋白、粗脂肪、钙和磷消化率不受影响,添加150mg/kg肉碱 可使断奶后0～14d的仔猪对粗脂肪的消化率比添加50mg/kg肉碱组显著降低14.6%(P＜0.05);添加100mg/kg肉碱可使断奶后 15～28d的仔猪对氨基酸的消化率比不添加组提高35%～3.8%(P＜0.01).表明日粮添加100mg/kg肉碱可以显著促进21日龄断奶 仔猪采食和极显著提高断奶后15～28d仔猪对日粮氨基酸的消化率,但对仔猪的生长速度和饲料转化率无显著影响. <饲料工业>,2000(11):9～11 用复方中章药添加剂饲养土鸡 中国科学院长沙农业现代化研究所汤少勋等采用江汉土鸡,比较了A组(混合型基础日粮+中草药添加剂)、B组(混合型基 础日粮+抗生素)、C组(玉米型基础日粮+中草药添加剂)和D组(玉米型基础日粮+抗生素)的饲喂效果.中草药添加剂为淮山、黄 柏、苍术、白术和红辣椒置65℃烘箱中烘干,粉碎过40目筛,然后与大蒜素按一定比例混合制成;抗生素为喹乙醇及土霉素钙 盐.结果表明:A组日增重比B、C、D组分别提高20.09%、18.67%、47.52%,经济效益分别提高26.37%、26.05%、59.75%,平均日 采食量提高1.07%、0.73%、9.55%;混合型日粮(玉米+米糠+次粉+大米)比玉米型日粮平均日增重提高20.25%,经济效益提高 26.04%,差异显著(P＜0.05);中草药添加剂日粮(A、C)比抗生素添加剂日粮(B、D)平均日增重提高22.36%,经济效益提高26.67%. 说明用稻米代替部分玉米,用中草药代替抗生素是可行的,尤以混合型日粮+中草药添加剂配伍最佳. <饲料研究>,2000(10):7～9 寡果糖对蛋用鹌鹑生产性能的影响 南京农业大学王国杰、柯叶艳等选用10月龄蛋用鹌鹑,研究日粮添加寡果糖(FOS)对产蛋、脂肪代谢及免疫、内分泌机能 的影响.结果表明,蛋用鹌鹑的产蛋率和蛋重提高、料蛋比下降.FOS 是一种良好的体内代谢改善剂,为肠道内有益菌提供营养 来源,对机体有间接的营养作用.该研究中,饲喂FOS后鹌鹑血液中三碘甲腺原氨酸(T3)浓度明显升高,提示FOS可通过促进 甲状腺分泌,与产蛋性能相关的甲状腺素增加,从而影响产蛋,并控制家禽的脂肪沉积,调节脂肪代谢,降低血清总胆固醇及蛋 黄胆固醇的含量.并且饲喂寡果糖所产生的大量双歧杆菌可通过提高细胞的免疫功能而产生抗癌作用,本研究也表明饲喂 FOS后,鹌鹑死亡率降低,T淋巴细胞转化率明显提高,提高了鹌鹑的免疫力. <畜牧与兽医>,2000(6):1～2 产蛋鸡日粮铜的添加 中国农科院饲料研究所齐广海、武书庚等用68周龄海赛克斯蛋鸡,研究玉米-大豆粕-棉仁粕型日粮中添加五水硫酸铜 (CuSO45H2O)形式的铜6mg/kg、30mg/kg、60mg/kg、125mg/kg和柠檬酸铜(CuCit)形式的铜6mg/kg、30mg/kg、60mg/kg. 试验结果表明:与对照组(含铜6.4mg/kg)相比,日粮中添加6mg/kg铜(硫酸铜)时耗料最低,蛋壳厚度最大,且随着添加量的 增加蛋壳厚度变薄;日粮中添加30mg/kg铜(硫酸铜)时产蛋率最高,料蛋比最低,蛋壳强度最大.日粮中添加不同铜源及水平 对蛋黄铜含量的影响不大(P＞0.05).与对照组相比,日粮中添加125mg/kg铜(硫酸铜)时肝脏铜水平明显升高(P＜0.05),但各添 加组之间的差异不显著(P＜0.05).随着日粮中铜添加水平的提高,蛋黄和肝脏胆固醇水平显著降低(P＜0.05).就相同添加水平而 言,柠檬酸铜比硫酸铜的降胆固醇效果更为明显. <动物科学与动物医学>,2000(6):14～16     

日粮中添加硒对断奶南江黄羊羔生长性能的影响

选用南江黄羊断奶羊羔10只,按性别、年龄、体重基本一致的原则随机分为对照组和试验组,每组4只公羊,1只母羊,进行45d舍饲饲养试验。试验组在与对照组基础日粮相同的日粮中添加0.15mg/kg的硒。结果表明:试验期对照组和试验组只均增重分别为(4.25±0.68)kg、(5.6±0.78)kg,平均日增重分别为93.34g和124.46g,两组间增重差异显著(P<0.05)。     

日粮中添加硒对断奶南江黄羊羔长性能的影响

选用南江黄羊断奶羊羔10只,按性别、年龄、体重基本一致的原则随机分为对照组和试验组,每组4只公羊,1只母羊,进行45d舍饲饲养试验.试验组在与对照组基础日粮相同的日粮中添加0.15mg/kg的硒.结果表明试验期对照组和试验组只均增重分别为(4.25±0.68)kg、(5.6±0.78)kg,平均日增重分别为93.34g和124.46g,两组间增重差异显著(P＜0.05).     

复合中草药多糖对断奶仔猪生产性能的影响

选用28日龄、体重相近、健康的"杜长大"三元杂交断奶仔猪64头,分为4组,每组16头。分别添加100g/t金霉素、0.05%、0.10%,0.15%的复合中草药多糖。结果表明:日粮中添加中草药复合多糖能显著提高断奶仔猪的采食量、平均日增重,降低料肉比;试验组腹泻率明显低于抗生素组(p<0.05)。表明在断奶仔猪日粮中添加0.1%复合中草药多糖能有效提高断奶仔猪的生产性能,降低仔猪的腹泻率。     

添加益生素对羔羊增重效果的影响

选用3月龄羔羊30只,随机分为3组。在基础日粮中加3个水平剂量的益生素(0.05g/只·d、0.10g/只·d、0.15g/只·d)饲喂47d,观察3个水平益生素对羔羊增重及生长发育的影响。试验表明:益生素的添加水平为0.10g/只·d时,育肥羔羊的增重、日增重、料肉比、钙、磷、粗蛋白的表观消化率最高,即羔羊饲料中0.10g/只·d剂量的益生素,可使育肥羔羊得到最佳的生长效果。     

高锌、抗生素对断奶后仔猪促生长防腹泻?

选用160头杜长大三元杂交，28日龄断奶仔猪分成4个组，分别饲以基础日粮(200ppmCu)、高锌日粮(200ppmCu＋2500ppmZn)、喹乙醇日粮(200ppmCu＋60ppm喹乙醇、杆菌肽锌日粮(200ppmCu＋50ppm杆菌肽锌)。结果显示，对照组、高锌组、喹乙醇组、杆菌肽锌组试验猪日增重分别为210g、263g、231g、214g，高锌组试验猪生长速度明显好于对照组和抗生素组，且料肉比和腹泻率也最低。     

元宝枫黄酮、大豆黄酮和金霉素对肉鸡生长性能和免疫机能影响的比较研究

选择300只1日龄AA雏公鸡随机分为4组,即基础日粮组(对照组)、添加5mg/kg金霉素组、添加10mg/kg大豆黄酮组和添加10mg/kg元宝枫黄酮组。与对照相比,各添加组在3周龄时对耗料量、体增重、料肉比无显著影响(P>0.05),七周龄时对体增重无显著影响(P>0.05),能显著降低耗料量(P<0.01)和改善料肉比(P<0.05)。添加元宝枫黄酮能显著提高T淋巴细胞的转化率(P<0.01)。与对照相比,添加大豆黄酮组和添加元宝枫黄酮组能显著提高红细胞C3b受体花环率。     

不同养殖密度对长江鲟稚鱼生长的影响

为了解不同养殖密度对长江鲟(Acipenser dabryanus)稚鱼生长的影响,设置初始密度为0.27(D 200)、0.46(D 350)、0.66(D 500)和0.87(D 650)kg/m2的4种养殖密度,对初始体重3.38 g和体长7.79 cm的2月龄长江鲟稚鱼进行4周的养殖实验。结果表明:养殖密度对体重、体长、变异系数(CV)、日增重(DWG)、净增重(NY)、特定生长率(SGR)和饵料系数(FCR)有显著影响,对存活率和肥满度无显著影响;D 200组的生长速度最快,与D 350组差异不显著,D 650组生长速度最慢;D 200组的体重、体长、特定生长率、日增重均最大,与D 350组无显著差异,但D 350组的变异系数和饵料系数均较D 200组要小;特定生长率与养殖密度(D)呈负相关关系:SGR=-1.171 5D+6.331 5(R2=0.484 5);变异系数与养殖密度呈正相关关系:CV=3.989 1D+13.533(R2=0.480 5)。此阶段长江鲟稚鱼最适养殖密度为D350(0.46 kg/m~2)。     

Growth performance and body composition of pacu Piaractus mesopotamicus (Holmberg 1887) in response to dietary protein and energy levels

Improper dietary protein and energy levels and their ratio will lead to increased fish production cost. This work evaluated effects of dietary protein : energy ratio on growth and body composition of pacu, Piaractus mesopotamicus. Fingerling pacu (15.5 ± 0.4 g) were fed twice a day for 10 weeks until apparent satiation with diets containing 220, 260, 300, 340 or 380 g kg^?1 crude protein (CP) and 10.9, 11.7, 12.6, 13.4 or 14.2 MJ kg^?1 digestible energy (DE) in a totally randomized experimental design, 5 × 5 factorial scheme (n = 3). Weight gain, specific growth rate increased and feed conversion ratio (FCR) decreased significantly (P < 0.05) when CP increased from 220 to 271, 268 and 281 g kg^?1 respectively. Pacu was able to adjust feed consumption in a wide range of dietary DE concentration. Fish fed 260 CP diets showed best (P < 0.05) protein efficiency ratio and FCR with 11.7–12.6 MJ kg^?1; but for the 380 CP‐diets group, significant differences were observed only at 14.2 MJ kg^?1 dietary energy level, suggesting that pacu favours protein as energy source. DE was the chief influence on whole body chemical composition. Minimum dietary protein requirement of pacu is 270 g kg^?1, with an optimum CP : DE of 22.2 g MJ^?1.     

生长期中华鳖饲料适宜能量_蛋白质水平及必需氨基酸模式的研究

以１５０ｇ左右的１７０只中华鳖为试验动物,随机分为１７个组。以饲料能量、蛋白质水平为试验因素,采用２因子５水平的回归正交旋转组合设计得到９个试验饲料营养组合,与１６个组试验动物相对应,进行６０ｄ饲养试验。试验结果,第９￣１６组鳖日增重２．２２ｇ／ｄ有显著地高于其它试验组（Ｐ〈０．０１）,比增设的对照组１．３８ｇ／ｄ高６０．８７％（Ｐ〈０．０１）,其饲料系数为１．４３,较其它组低１２．２７％￣４５．     

日粮能量水平对肉鸭生产性能影响及“标准曲线法”测定饲用酶制剂的表观代谢能值

本试验选用14日龄花边肉鸭(生长速度介于本地麻鸭和快大型肉鸭的肉鸭品种)共444只,随机分为4组,每组设三个重复,每个重复37只,分别饲喂代谢能(ME)10.878、10.460、10.042MJ/kg及9.623MJ/kg+复合酶(1kg/t饲料)的四种日粮处理,各日粮处理的原料组成、粗蛋白含量、可消化赖氨酸及含硫氨基酸含量相同。试验期间试鸭自由采食和饮水。14d的试验结果表明,在10.878～10.042MJ/kg范围内日粮ME和肉鸭采食量及耗料/增重(FCR)呈显著(p相似文献   

Effect of dietary DP/DE ratio on apparent digestibility, growth and nitrogen and phosphorus retention in rainbow trout, Oncorhynchus Mykiss (Walbaum)

The effect of DP/DE ratio in diets for rainbow trout, Oncorhynchus mykiss (Walbaum), was investigated. To evaluate growth and body composition, groups of trout were fed three experimental diets with a constant level of gross energy (25.4 ± 0.12 MJ kg^?1 dry matter (DM)) and different digestible protein/digestible energy (DP/DE) ratios (diet A, 16. 35; diet B, 17.21; dietC, 18.23 g Mr^?1). Fat, protein and energy digestibility coefficients were not affected by the DP/DE ratio of the diets. Growth and feed utilization improved markedly as dietary DP/DE ratio increased (P < .01). The efficiency of fat, protein and energy utilization tended to increase with increasing DP/DE ratio of the diets. Nitrogen discharge in effluent water per kg of weight gain was not affected by dietary treatments (mean values for: diet A, 29.9; diet B, 29.8; diet C, 29.1 g N kg^?1 weight gain) while phosphorus discharge in effluent water fell using diets with a higher DP/DE ratio (mean values for: diet A, 7.3; diet B, 6.7; diet C, 5.9 g P kg^?1 weight gain).     

Optimum dietary protein and lipid specifications for grow-out of humpback grouper Cromileptes altivelis (Valenciennes)

Fingerling Cromileptes altivelis of less than 50 g have been shown to require feeds of 50–56% crude protein (CP) and 9–15% lipid. The requirements of larger, market‐size fish have not been reported. A total of 324 hatchery‐produced C. altivelis were weight sorted into three groups of 136, 175 and 225 g start weight and equally (12 seacage^?1) and randomly distributed to floating net seacages in accordance with a 3 × 3 factorial arrangement of CP (42%, 47% or 53%; estimated digestible CP of 40%, 46% or 52%) and lipid (8%, 12% or 16%; equivalent to estimated digestible energy (DE) contents of 14.0, 15.8 or 17.5 MJ kg^?1). Changes in dietary CP and lipid content were achieved at the cost of wheat flour by proportionally varying the protein mixture (essentially a 0.62:0.22:0.16 ratio of fish meal, mysid meal and casein respectively) and oil mixture (a 2:1 ratio of fish oil and soybean oil respectively). Fish were fed twice daily to satiation for 180 days. There was no significant (P>0.05) interaction between the main effects of dietary protein and lipid for any growth, nutrient retention or whole‐body composition measurements. Increasing dietary CP significantly improved the survival rate (80.6%, 88.9% and 87.0%), specific growth rate (SGR; 0.24%, 0.28% and 0.31% day^?1), feed conversion ratio (FCR; 2.77, 2.21 and 2.00) and DE retention (18.2, 21.3 and 23.2%), respectively, but did not significantly affect digestible protein retention. Increasing dietary lipid increased SGR (0.25, 0.29 and 0.29% day^?1) and the whole‐body lipid (and energy) composition, and reduced the survival rate (87.0%, 88.9% and 80.6%), respectively, but FCR and retentions of digestible protein and DE were not significantly affected. These results indicate that humpback grouper of 150–400 g require a dietary specification of not less than 51% digestible protein (～53% CP), 10–12% lipid and digestible protein:DE of 31–32 g MJ^?1 for optimal growth.     

Response of Nile tilapia (Oreochromis niloticus) to diet acidification: Effect on growth performance and feed utilization

A 12-week feeding trial was undertaken to assess growth, nutrient utilization, some hematological parameters, and proximate composition of Nile tilapia (Oreochromis niloticus) fed diets supplemented with graded levels (0.5%, 1.0%, and 1.5%) of two blends of organic acids or organic salts. Seven isonitrogenous (300 g CP kg^?1) and isocaloric (19.0 MJ gross energy kg^?1) diets were formulated. The control diet (D1) contained neither added blend of organic acids nor organic salts. Three diets (D2, D3, and D4) were supplemented with 0.5%, 1.0%, and 1.5% of malic acid + oxalic acid blend (OAB), respectively. The other three diets (D5, D6, and D7) were supplemented with 0.5%, 1.5%, and 1.5% of calcium lactate + sodium acetate blend (OSB), respectively. Fingerlings (7.05 ± 0.02 g) were randomly distributed into 21 glass aquaria (160 liter), with each aquarium holding 15 fish. At the end of the feeding trial, O. niloticus offered the control diet showed lower growth and feed utilization than all those fed the organic acids or organic salts blends supplemented diets. Fish fed the diet D3 showed the highest body weight (BW), body length (BL), weight gain (WG), specific growth rate (SGR), feed intake (FI), and the best feed conversion ratio (FCR) and protein efficiency ratio (PER). Fish fed diet supplemented by 1.5% OAB (D4) showed the highest serum protein content, while control group (D1) showed the lower level of total lipids compared with the other treatments. Fish group fed the diet supplemented with 0.5% of OSB (D5) showed the highest protein and ash contents and the lowest lipid content of the whole fish body, while the control group showed the lowest protein and the highest fat content. The present observations suggest that the growth, feed utilization, and health status of juvenile O. niloticus can be enhanced with a supplementation of 1% of OAB or OSB in the diet.     

Dietary composition manipulation to enhance the performance of juvenile barramundi (Lates calcarifer Bloch) reared in cool water

Barramundi Lates calcarifer reared in cool water (20–22°C) grow slowly and feed is used poorly compared with fish in warm water (28–32°C). Two comparative slaughter growth assays were carried out with juvenile barramundi to see if increasing the digestible energy (DE) and/or the n‐3 highly unsaturated fatty acid (n‐3 HUFA) content of the feed would improve growth of fish raised in cool water. Increasing the DE content of the feed from 15 to 17 or 19 MJ kg⁻¹ while maintaining a constant protein to energy ratio in Experiment 1 brought about significant improvements in feed conversion ratio (FCR) (from 2.01 to 1.19) and daily growth coefficient (DGC; from 0.69 to 1.08%/day) for fish at 20°C. For fish at 29°C, improvements, while significant, were of a lesser magnitude: from 1.32 to 0.97 for FCR and from 3.24 to 3.65%/day for DGC. Increasing the absolute amount of dietary n‐3 HUFA, expressed as the sum of eicosapentaenoic and docosahexaenoic fatty acids, from 0.5% to 2.0% in Experiment 2 improved DGC linearly and FCR curvilinearly for fish at 29°C whereas at 20°C, DGC was not affected while FCR improved slightly (from 1.83 to 1.68). Feed conversion ratio was optimized with a dietary n‐3 HUFA of about 1.5%. Providing barramundi with a feed that is high in DE (viz 19 MJ kg⁻¹) and a digestible protein to DE ratio of 22.5 g MJ⁻¹ is a practical strategy for improving the productivity of barramundi cultured in cool water whereas increasing dietary n‐3 HUFA conferred very little additional benefit.     

Growth and efficiency of feed usage by Atlantic salmon (Salmo salar) fed diets with different dietary protein: Energy ratios at two feeding levels

The effect of dietary digestible protein/digestible energy (DP/DE) ratios and feeding level on growth, feed efficiency, nutrient and energy usage by Atlantic salmon ( Salmo salar ; initial body weight, 7.0 g/fish) at 15°C was investigated in a 16-week feeding trial. Three diets, differing in their DP and DE contents, namely 37/18 (regular diet, RD), 37/21 (high fat diet, HF) and 44/ 22 (high nutrient-dense diet, HND) g/MJ of dry feed were formulated. DP/DE ratios were 20, 18 and 20 g/MJ for the RD, HF and HND diets, respectively. Salmon were hand-fed three times a day at either 100% or 85% of the feed requirement estimated by a bioenergetics model. At each feeding level, DE intake (kJ/fish) was similar for all three diets. Diet composition did not affect growth rate. However, increasing the digestible energy density from 18 to 22 MJ/kg of dry feed resulted in a significant increase ( P  < 0.05) in feed efficiency. Restricting feed intake significantly decreased live body weight gains for all diets. However, feed efficiency was not affected by feeding level. Diet composition and feeding level did not affect carcass composition and nutrient and energy usage, with the exception of a higher ( P  < 0.05) carcass lipid of fish fed the HF100 diet compared with the fish fed the RD and HND diets and a higher ( P  < 0.05) lipid gain (g/fish) of fish fed the HF100 diet compared with fish fed all the diets at the restricted feeding level. Restricting feeding resulted in significantly lower ( P  < 0.05) energy gain (kJ/fish) compared with fish fed at 100%. Increasing the DE and nutrient density of the diet had no effect on growth but improved feed efficiency and lowered solid wastes (g of solid wastes per kg of fish produced) while dissolved wastes were not affected by dietary ormulation.