Debaryomyces hansenii supplementation in low fish meal diets promotes growth,modulates microbiota and enhances intestinal condition in juvenile marine fish

Background The development of a sustainable business model with social acceptance,makes necessary to develop new strategies to guarantee the growth,health,and well-being of farmed animals.Debaryomyces hansenii is a yeast species that can be used as a probiotic in aquaculture due to its capacity to i)promote cell proliferation and differen-tiation,ii)have immunostimulatory effects,iii)modulate gut microbiota,and/or iv)enhance the digestive function.To provide inside into the effects of D.hansenii on juveniles of gilthead seabream(Sparus aurata)condition,we inte-grated the evaluation of the main key performance indicators coupled with the integrative analysis of the intestine condition,through histological and microbiota state,and its transcriptomic profiling.Results After 70 days of a nutritional trial in which a diet with low levels of fishmeal(7%)was supplemented with 1.1%of D.hansenii(17.2×10^(5) CFU),an increase of ca.12%in somatic growth was observed together with an improve-ment in feed conversion in fish fed a yeast-supplemented diet.In terms of intestinal condition,this probiotic modu-lated gut microbiota without affecting the intestine cell organization,whereas an increase in the staining intensity of mucins rich in carboxylated and weakly sulphated glycoconjugates coupled with changes in the affinity for certain lectins were noted in goblet cells.Changes in microbiota were characterized by the reduction in abundance of several groups of Proteobacteria,especially those characterized as opportunistic groups.The microarrays-based transcrip-tomic analysis found 232 differential expressed genes in the anterior-mid intestine of S.aurata,that were mostly related to metabolic,antioxidant,immune,and symbiotic processes.Conclusions Dietary administration of D.hansenii enhanced somatic growth and improved feed efficiency param-eters,results that were coupled to an improvement of intestinal condition as histochemical and transcriptomic tools indicated.This probiotic yeast stimulated host-microbiota interactions without altering the intestinal cell organization nor generating dysbiosis,which demonstrated its safety as a feed additive.At the transcriptomic level,D.hansenii pro-moted metabolic pathways,mainly protein-related,sphingolipid,and thymidylate pathways,in addition to enhance antioxidant-related intestinal mechanisms,and to regulate sentinel immune processes,potentiating the defensive capacity meanwhile maintaining the homeostatic status of the intestine.

An initial investigation replacing fish meal with a commercial fermented soybean meal product in the diets of juvenile rainbow trout

The inclusion of PepSoyGen (PSG), a commercially-available fermented soybean meal product, was evaluated with juvenile rainbow trout, Oncorhynchus mykiss in an initial 70-day feeding trial, with a supplemental trial involving a subset of the experimental diets continuing for an additional 40 d. Six diets containing 0%, 10%, 20%, 30%, 40%, or 50% PSG, with the PSG directly replacing fish meal, were used in the first trial. There were no significant differences in weight gain or feed conversion ratio between the fish meal-based control diet and diets containing up to 30% PSG. However, weight gain was significantly reduced and feed conversion ratio significantly increased with the 40% and 50% PSG diets. No health assessment differences were observed in fish receiving any of the diets, and no evidence of gross gut inflammation was evident. There were no significant differences in weight gain or feed conversion ratio among the four dietary treatments ranging from 0% to 30% PSG which were fed for an additional 40 d after the initial 70-d trial (110 days total). Based on these results, juvenile rainbow trout diets can contain up to 30% PSG without any loss of rearing performance, thereby replacing at least 60% of the fish meal.

Effects of Brown Fish Meal Replacement with Fermented Soybean Meal on Growth Performance, Feed Efficiency and Enzyme Activities of Chinese Soft-shelled Turtle, Pelodiscus sinensis

A 120-day feeding experiment was conducted to investigate the effects of partial replacement of brown fish meal (BFM) by fermented soybean meal (FSBM) in diets of Chinese soft-shelled turtle (Pelodiscus sinensis). The turtles (initial mean body weight, (115.52 ± 1.05) g) were fed with three experimental diets, in which 0%, 4.72% and 9.44% BFM protein was replaced by 0%, 3% and 6% FSBM, respectively. Results showed that the feeding rate (FR), specific growth rate (SGR) and feed efficiency ratio (FER) of turtles fed with the diet containing 3% FSBM were not significantly different from the control group (0% FSBM) (P > 0.05). However, FR, SGR and FER of turtles fed with the diet containing 6% FSBM were significantly lower than those of the control group (P < 0.05). No significant differences were observed in the activities of serum glutamic-oxalacetic transaminase and glutamicpyruvic transaminase among dietary treatments (P > 0.05). However, the uric acid concentration in turtles fed with the diet containing 3% or 6% FSBM was significantly lower than that in the control group (P < 0.05). There were no significant differences in the activities of lysozyme, alkaline phosphatase and total superoxide dismutase among dietary treatments (P > 0.05). The results suggested that FSBM could replace 4.72% BFM protein in turtle diets without exerting adverse effects on turtle growth, feed utilization and measured immune parameters.

Effect of Replacing Fish Meal with Extruded Soybean Meal on Growth, Feed Utilization and Apparent Nutrient Digestibility of Juvenile White Shrimp(Litopenaeus vannamei)

Extruded soybean meal(ESBM) was evaluated as a protein source for partial replacement of fish meal(FM) in diets of juvenile Litopenaeus vannamei. In the control diet(Diet 1), FM protein was replaced with increasing dietary levels of ESBM(4.28%, 8.40%, 12.62%, 16.82%, and 25.26%) at 10%, 20%, 30%, 40%, and 60% levels(Diets 2 to 6, respectively). An eight-week feeding trial was conducted on 720 juvenile shrimp(0.67 g ± 0.01 g mean initial weight), and nutrient digestibility of the six diets was determined. ESBM could replace 20% of FM without causing a significant reduction in growth of shrimp, but other dietary treatments strongly affected whole body composition. Crude protein content of the whole body fed Diet 6 was significantly lower than that fed Diet 2(P < 0.05), while crude lipid content of the whole body fed Diet 5 or 6 was significantly higher than that fed Diet 2(P < 0.05). Protein digestibilities of Diets 5 and 6 were significantly lower than that of Diet 1(P < 0.05). Digestibility of lipids ranged from 96.97% in Diet 6 to 98.34% in Diet 3, whereas dry matter digestibility decreased with increasing replacement level. This study indicates that 20% FM replacement with ESBM in the basic diet containing 40% protein and 30% FM is optimal for juvenile L. vannamei.

Rearing Performance of Juvenile Brown Trout (<i>Salmo trutta</i>) Subjected to Exercise and Dietary Bioprocessed Soybean Meal

This 121-day experiment evaluated the rearing performance of brown trout Salmo trutta fed one of two isonitrogenous and isocaloric diets and reared at velocities of either 2.8 or 16.1 cm/s. Fishmeal was the primary protein source for the reference diet, and bioprocessed soybean meal replaced approximately 67% of the fishmeal in the experimental diet. At the end of the experiment, there were no significant differences in gain, percent gain, feed conversion rates, or specific growth rates between the dietary treatments. There were also no significant differences in intestinal morphology, splenosomatic, hepatosomatic, and viscerosomatic indices related to diet composition. However, gain, percent gain, feed fed, and specific growth rate were all significantly greater in brown trout reared at the higher velocity. No significant differences in any of the other variables measured were observed between the velocity treatments. There were no significant interactions between diet and velocity in any of the variables. Based on the results of this study, bioprocessed soybean meal can replace at least 67% of the fishmeal in brown trout diets, regardless of the rearing velocities used in this study. However, higher rearing velocities are recommended to maximize juvenile brown trout growth rates.

Soybean meal as a source of protein in formulated diets for tiger grouper, <i>Epinephelus fuscoguttatus</i>juvenile. Part I: Effects on growth, survival, feed utilization and body compositions

The effects of fish meal (FM) replacement with graded level of soybean meal (SBM) on growth performance, feed utilization, survival rate and body composition were investigated in juvenile tiger grouper, Epinephelus fuscoguttatus (initial body weight 13.9 ±0.65 g). Six experimental diets were formulated to contain 50% crude protein, 16% crude lipid and 365.8 kcal/100g feed with SBM replacing FM protein at 0% (SM 0), 10% (SM 0), 20% (SM 20), 30% (SM 30), 40% (SM 40) and 20% with phytase (SM 20P) replacement levels. At the end of the ten-week feeding trial, there were no significant differences detected in terms of growth performances (weight gain and specific growth rate), feed conversion ratio (FCR) and survival rates of fish fed with the control diet (SM 0), SM 20, SM 30 and SM 20P. Net protein utilization of fish fed SM 20P was higher than those fed with other diets suggesting an improved utilization of nutrients with phytase addition in the diet. Replacements of FM protein with SBM at 10% and 40% have resulted in significantly lower growth and poorer FCR than other replacement levels. Survival rates remain high (≥90%) throughout the trial. Whole-body proximate composition of the fish was significantly affected by the inclusion of SBM in the diets. It can be concluded that 20%-30% of FM protein replacement with SBM is recommended and addition of phytase in the SBM-based diet should be considered to improve nutrient utilization of tiger grouper juvenile.

Effect of Fish Meal Replacement by Unconventional Meal in the Post-Larval Diet of Clarias Gariepinus in Benin (West Africa)

To reduce the pressure on aquatic resources due to the use of fishmeal in fish feed, the mastery and use of alternative sources of fishmeal in all stages of fish development are essential. Five diets including 4 experimental and one control diet were considered. Experimental diets of post-larvae were developed from unconventional ingredients in which fishmeal was completely replaced by a mixture of brewer’s yeast, chicken viscera and maggots. These foods were tested on Clarias gariepinus post-larvae with an initial average weight of 80 ± 1 mg. 1500 fish individuals were equally distributed in 15 concrete basins with a volume of 500 L forming five treatments in triplicate. Fish individuals were fed, manually at a ration rate of 20%, four times per day. The specific growth rates were 8.38%/day in imported food and 6.35%/day in the experimental food receiving 45.5% of protein from unconventional meal. Similar results were obtained with the feed consumption index. These encouraging results show that it is possible to partially or completely replace fishmeal in catfish feed and obtain an economically profitable production. The recovery of waste such as chicken viscera, brewer’s yeast and soybean meal in fish food formulation as tested in this study is a good contribution to environmental sanitation.

Effects of Rations Containing Maggot Concentrate as a Fish Substitute on the Technical and Economic Performance of Large White’s Piglets in Burkina Faso

The study evaluated the effects of rations incorporating maggot concentrate (CA) as a substitute for fishmeal on growth performance and post-weaning piglet’s production costs. To do this, twenty-four (24) weanlings of large white breed were divided into 3 batches of 8 pigs each for a comparative rationing test in 2 phases. Four (04) experimental rations containing CA, two experimental rations (RI10 and RI5-5) for the 1st phase and two others (RII5 and RII10) for the 2nd phase were tested in comparison with 2 control rations RTI10 and RTII5 for the respective Phases I and II. The results show that in all phases piglet growth was continuous from the beginning to the end of each phase. In Phase I, the ADGs of piglets fed RI5-5 (138.64 g), RI10 (131.28 g) and RTI10 (104.78 g) were homogeneous (p > 0.05). The food production costs of one kg of live weight (FCkgLW) of the RI5-5 (671.39 CFAF) and RI10 (690.57 CFAF) rations were significantly lower than the RTI10 (1083.68 CFAF) ration (p < 0.05). In Phase II, the ADG of RII5 (249.85 g), RII10 (260.36 g), and RTII5 (248.00 g) were homogeneous (p > 0.05). The FCkgLWs of RII10 (506.73 FCFA), RII5 (583.43 FCFA) and RTII5 (815.53 FCFA) were homogeneous (p > 0.05). The maggot concentrate can be used as a source of animal protein in the feeding of piglets in partial or total substitution for fish. The evaluation of the effects of its use on the quality of carcasses and meat will be necessary.

Review on Using of Housefly Maggots(Musca domestica)in Fish Diets

The main animal protein ingredient in fish diets is most often fishmeal because of its nutritional quality.However,the limited availability and increasingly cost of fishmeal has lead to investigations of either lowering or replacing the fishmeal content with more economic protein sources of animal and/or plant origin.The research for appropriate and cheap cost alternative sources of protein to use in commercial fish diets will be the most important factor in intensive fish culture development.Insect meals are healthy and nutritious alternatives to fish meal due to their rich nutritional values,particularly protein,fat and minerals.Housefly maggots(Musca domestica)meal is also rich in B complex vitamins,trace elements and phosphorus.From the results of previous studies,Housefly maggots meal can be used successfully to replace the fish meal portion partially or completely in the fish diets.Also,the results observed that not physiological stressful was introduced in the fish by feeding Housefly maggots meal diets.This indicates that Housefly maggots meal were well utilized by the fish thus resulting in good growth of fish.In other study,observed a best growth performance with fish feeding on diets containing maggot’s meal compared with fish feeding on fishmeal diet.This indicates the high nutritional quality and fish acceptance of maggot’s meal.

低蛋白质低豆粕多元化饲粮是养猪节粮增效的关键技术

通过补充适宜种类和数量的工业合成晶体氨基酸,低蛋白质饲粮可以精准满足猪快速生长所需的氨基酸营养需求,避免蛋白质饲料浪费及减少粪、尿氮排放。低蛋白质低豆粕多元化饲粮是以低蛋白质饲粮生产技术为基础,依据各种能量饲料和蛋白质饲料的可利用养分等,配制的原料种类多、养分互补性强、营养平衡度高的低豆粕饲粮。低蛋白质低豆粕多元化饲粮可有效增强猪对饲粮中营养物质的消化、吸收和沉积,降低饲粮中豆粕、玉米等原料的用量,对节粮增效及提高养猪效率具有重要意义。本文从研究与应用进展、对生猪养殖效率的影响、合成氨基酸与天然氨基酸效率对比、氨基酸数量需求情况及产能等方面分析,综述了猪低蛋白质低豆粕多元化饲粮技术、应用效果及前景,以期为相关研究及应用工作提供一定的参考和帮助。

低豆粕、低蛋白水平日粮对尼古拉火鸡生长性能的影响研究

试验旨在探究低豆粕、低蛋白日粮对尼古拉火鸡生长性能的影响。选择1日龄尼古拉火鸡360只,结合体型、性别比例随机分为9组,每组设4个重复,每个重复10只鸡。实验分为0~4周龄以及5~8周龄两个阶段,并使用3×3双因素试验方法,研究常规蛋白质水平日粮(玉米-豆粕型、玉米-低豆粕添加型、糙米-玉米-低豆粕添加型)、蛋白质水平由27%降至25%日粮(玉米-豆粕型、玉米-低豆粕添加型、糙米-玉米-低豆粕添加型)、蛋白质水平由27%降至23%日粮(玉米-豆粕型、玉米-低豆粕添加型、糙米-玉米-低豆粕添加型)对尼古拉火鸡生长性能的影响。结果显示,与常规蛋白质水平、玉米-豆粕型日粮组相比,降低4个百分点蛋白质水平日粮(玉米-豆粕型、玉米-低豆粕添加型、糙米-玉米-低豆粕添加型)火鸡全期增重显著降低(P<0.05),但料重比显著增高(P<0.05),饲料利用率较差。研究表明,尼古拉火鸡日粮的蛋白质水平在0~4周龄阶段由27%降低到25%,5~8周龄阶段由25%降低至23%,火鸡的增重及饲料报酬未受到显著影响,但进一步降低日粮蛋白质水平将会导致火鸡生长性能显著下降。

响应面法优化复合益生菌固态发酵玉米-豆粕型日粮工艺

研究旨在对复合益生菌发酵玉米-豆粕型日粮产生酸溶蛋白的工艺进行优化,为复合益生菌发酵饲料的应用提供参考。在单因素试验的基础上以酸溶蛋白含量为响应值,以接种量、料水比、发酵时间、发酵温度为自变量,通过Box-Behnken设计试验,优化复合益生菌发酵玉米-豆粕型日粮的发酵工艺。结果表明:乳酸杆菌RSG-1∶枯草芽孢杆菌B-1∶地衣芽孢杆菌Y5-39为1∶1∶4时,酸溶蛋白含量最高为5.30%;响应面优化后复合益生菌最佳发酵工艺为:含水量48%,接种量10%,发酵温度48℃,发酵时间10 d,酸溶蛋白含量为13.31%,在考虑生产实际的情况下,将发酵温度调整为37℃。综上,研究确定了多菌种组合固态发酵玉米-豆粕型日粮的最佳工艺条件:含水量为48%、接种量(乳酸杆菌∶枯草芽孢杆菌∶地衣芽孢杆菌=1∶1∶4)10%、发酵温度37℃、发酵时间10 d,酸溶蛋白含量达到13.06%。

畜禽日粮豆粕减量替代研究进展

豆粕作为传统的饲料蛋白质来源,具有优质、营养丰富的特点,但其价格波动大,成本较高,且对大豆进口依赖性较高。因此,寻找饲料蛋白质替代是当前的国家战略需求和营养研究热点。替代旨在降低饲料成本、减少对豆粕的依赖,并提高动物饲料蛋白应用的可持续性。本文从豆粕减量替代的意义、不同豆粕替代原料的研究和应用现状进行了综述,以期为日粮或饲料中豆粕减量替代提供参考。

不同植物蛋白源替代鱼粉对青鱼生长及免疫的影响

该试验聚焦青鱼的饲料创新方法,通过应用不同植物蛋白源替代鱼粉对青鱼生长性能、全鱼和肌肉化学成分组成、肠道及肝胰脏酶活的影响。将豆粕SBM、菜粕RSM、棉粕CSM、花生粕PM分别替代试验饲料中10%的鱼粉FM(CP,67%),配制成5组等氮等能的试验饲料,分别记为FM、SBM、RSM、CSM、PM。以鱼粉、豆粕、菜粕、棉粕、花生粕为主要蛋白源按相同成分含量配制成粗蛋白(39.34%)、粗脂肪(6.81%)的青鱼配合饲料,并以此为对照组进行试验。研究结果表明,豆粕相较于其他植物蛋白源更适合加入饲料,用豆粕替代试验饲料中<10%的鱼粉较为理想。

豆粕替代鱼粉对泰国虎纹蛙生长性能的影响

为了探讨发酵豆粕代替鱼粉对泰国虎纹蛙(Hoplobatrachus rugulosus)生长性能的影响,该研究选用180只规格为24g/只~28g/只的泰国虎纹蛙为试验对象,试验共设置6个处理小组。根据发酵豆粕代替鱼粉的比例,分别为0%组、20%组、40%组、60%组、80%组和100%组。每个小组的泰国虎纹蛙30只,分3个重复,每个重复10只。试验为期60 d。结束后测定泰国虎纹蛙的增重情况。试验结果显示,发酵豆粕代替鱼粉对泰国虎纹蛙的摄食率和成活率影响不显著;增重率0%组和20%组的差异不显著;40%组、60%组和80组和0%组对比差异不显著,但是显著地低于20%组(P<0.05);100%组的增重率最低,显著地低于对照组、40%组、60%组和80%组(P<0.05),极显著地低于20%组(P<0.01);饲料效率以20%组的最高,但是和0%组、40%组、60%组和80%组的差异不显著,显著地高于100%组(P<0.05)。试验结果表明,以20%的发酵豆粕替代鱼粉,可以提高泰国虎纹蛙的生长性能。

Analysis of Overall Popularization of Low-Protein Diet

The shortage of protein feed resources and environmental pollution restrict the healthy and sustainable development of breeding industry,so it is imperative to promote low protein diet. Based on the current industry trends and national policies, this paper analyzes the background con-ditions, significance and specific measures of popularizing low-protein diets, in order to provide policy, theoretical and technical support for the im-plementation of low-protein diets throughout the year.

低鱼粉饲料中黑水虻幼虫粉替代鱼粉对合方鲫生长性能、消化能力、血浆生化指标及相关基因表达的影响

实验以合方鲫2号幼鱼(31.50±0.50)g为实验对象,研究黑水虻幼虫粉(HM)替代饲料鱼粉(0、20%、40%、60%和80%)对合方鲫生长性能、饲料利用、消化能力、血浆生化指标及相关基因表达的影响。实验设计5组等氮(30%)等能(18.50 MJ/kg)等脂(6%)饲料,每组3次重复,每个重复25尾鱼,养殖时间74d。结果表明:增重率和特定生长率随饲料HM含量的升高呈现先升高后降低趋势,且在替代水平为20%时最大;饲料系数呈先降低后升高的趋势,20%替代组显著小于60%和80%替代组(P<0.05)。肥满度和脏体比均呈现先升高后降低趋势,且均在40%替代组最大;80%替代组肝体比显著高于0、20%和60%替代组(P<0.05),但与40%替代组无显著差异。全鱼水分和灰分无显著变化;20%和60%替代组粗蛋白显著低于0组(P<0.05);粗脂肪呈先升高后降低的变化趋势,在20%替代组达到最大值。血浆葡萄糖、总胆固醇含量及谷丙转氨酶、谷草转氨酶活性无显著差异;血氨含量呈上升趋势,80%替代组显著高于0组;20%替代组血浆总氨基酸含量显著高于其他各处理组(P<0.05);60%和80%替代组血浆丙二醛含量显著低于20%替代组(P<0.05)。20%替代组肠道中lat2、pept1和cdx2基因的表达量均高于其他各处理组,asct2基因表达水平则在替代水平为40%时最大;肝脏中tor和igf1基因表达量均在40%替代组最大,gh和ghr基因表达水平则均在替代水平为60%时最高。黑水虻幼虫粉替代饲料中鱼粉的0—40%不影响合方鲫的生长,且在20%替代水平时可获得最大生长速率。

实用饲料中棉籽浓缩蛋白替代鱼粉对凡纳滨对虾生长性能和肌肉品质的影响

本研究旨在探究实用饲料中棉籽浓缩蛋白替代鱼粉对凡纳滨对虾生长性能和肌肉品质的影响。在鱼粉含量为200 g/kg的基础饲料中,分别以0、52、104、156、208 g/kg棉籽浓缩蛋白等蛋白质替代基础饲料中0、25%、50%、75%、100%的鱼粉,制成5种等氮等脂试验饲料(FM20、FM15、FM10、FM5和FM0),并补充主要限制性氨基酸和胆固醇,饲喂初始体重为(1.20±0.05)g的凡纳滨对虾56 d。结果显示:与对照组(FM20组)相比,FM15、FM10组的生长性能无显著差异(P>0.05),FM5、FM0组的增重率分别下降13.3%、16.2%(P<0.05),饲料系数分别升高0.11、0.13(P<0.05);FM10、FM5、FM0组的出肉率显著降低(P<0.05)。在肌肉品质方面,各鱼粉替代组的体色以及肌肉质构特性(硬度、弹性、黏聚性、咀嚼性、剪切力)、常规成分与氨基酸(异亮氨酸和酪氨酸除外)含量和游离氨基酸、游离鲜味氨基酸总量与对照组相比均无显著差异(P>0.05);各组在肌肉超氧化物歧化酶(SOD)活性和胶原蛋白、丙二醛(MDA)、游离棉酚含量上也无显著差异(P>0.05)。综上可知,在鱼粉含量为200 g/kg的实用饲料中,在补充主要限制性氨基酸和胆固醇的条件下,棉籽浓缩蛋白可以替代100 g/kg(50%)的鱼粉而对凡纳滨对虾的生长性能和肌肉品质没有显著影响。

玉米-小麦-豆粕型饲粮中添加纤维素复合酶对蛋鸡生产性能、蛋品质、养分表观代谢率和肠道食糜黏度的影响

本试验旨在研究纤维素复合酶(主要成分为纤维素酶、木聚糖酶、淀粉酶和蛋白酶)在蛋鸡玉米-小麦-豆粕型饲粮中的应用效果。选取53周龄海兰褐蛋鸡288只,随机分为4个组,每个组6个重复,每个重复12只鸡。对照组饲喂玉米-小麦-豆粕型饲粮,试验组分别在对照组饲粮的基础上添加200、400和600 mg/kg的纤维素复合酶。预试期为7 d,正试期为84 d。结果显示:1)与对照组相比,200、400、600 mg/kg组蛋鸡的产蛋率分别显著提高了2.72%、3.28%、5.39%(P<0.05);400和600 mg/kg组蛋鸡的平均日采食量及料蛋比显著降低(P<0.05)。2)400和600 mg/kg组鸡蛋蛋黄颜色显著高于对照组(P<0.05)。3)600 mg/kg组蛋鸡的能量表观代谢率显著高于对照组(P<0.05),400和600 mg/kg组蛋鸡的粗蛋白质表观代谢率显著高于对照组(P<0.05)。600 mg/kg组蛋鸡的能量表观代谢率显著高于200和400 mg/kg组(P<0.05),粗蛋白质表观代谢率各试验组间差异不显著(P>0.05)。4)与对照组相比,400和600 mg/kg组蛋鸡十二指肠食糜黏度显著降低(P<0.05),各试验组蛋鸡回肠食糜黏度均显著降低(P<0.05),其中400 mg/kg组比对照组降低15.79%。5)200、400、600 mg/kg组的利润比对照组分别提高了11.01%、19.74%、16.64%,其中400 mg/kg组蛋鸡产生的经济效益最好。6)通过建立料蛋比(y)与纤维素复合酶添加量(x)之间的回归方程y=11.072×10^(-7)x^(2)-0.001x+2.331,计算出获得最小料蛋比时的纤维素复合酶添加量为451.59 mg/kg。结合生产性能和经济效益,在本试验条件下,蛋鸡玉米-小麦-豆粕型饲粮中纤维素复合酶的适宜添加量为400 mg/kg。