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.

Effect of the Dietary Substitution of Fish Meal with Achatina fulica Meat Meal on the Growth Performance and Production Cost of African Catfish (Clarias gariepinus) Fingerlings

Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African giant land snails, was tested as a fishmeal substitute for Clarias gariepinus growth. Five iso-nitrogenous and iso-calorific diets were formulated, in which AFM substituted fish meal at 0% (control or Diet A), 25% (Diet B), 50% (Diet C), 75% (Diet D) and 100% (Diet E). These dietary treatments were each replicated thrice in a completely randomized design experiment, using 36-L plastic tanks in which the fish were fed daily rations corresponding to 5% of their body weight, for 8 weeks. Water quality parameters in the tanks were monitored. Proximate analyses were conducted on the fish meal, snail meal and experimental diets before the feeding trials. Cost-benefit analysis of the different diets was performed. The crude protein content of AFM (69.18%) was significantly higher than that of fish meal (55.81%). There was no significant difference (P > 0.05) in the mean weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and survival rate in fish fed Diet A and Diet B. The best protein efficiency ratio (0.77) was recorded in fish fed Diet B. Furthermore, the survival rate of fish increased with increased levels of AFM substitution. Water quality parameters were within a suitable range for tropical fish culture, indicating that the AFM did not pollute the water. The fish fed 25% AFM diet significantly (P Clarias gariepinus diets at a 25% substitution level. The aquaculture industry can thus exploit the availability of this feed resource.

Effect of Fish Meal Replacement with Maggot Meal on the Growth Performance of Misgurnus anguillicaudatus

Maggot meal was used to replace 0, 20% , 40% , 60% , 80% , 100% of the fish meal in the hasal feed, getting 6 kinds of feed with the same nitrogen content and equal energy （marked as group H0, H20, H40, H60, H80, H100）, which were used to feed the Misgurnus anguillicaudatus （loach） for60 d. The effects of the fish meal replacement by maggot meal on the growth performance of M. anguiUicaudatus were studied by comparing the growth performances and body indica- tors of M. anguillicaudatus fed with different feed groups. The results showed that the final weight, weight gain rate, specific growth rate of the M. anguillicaudatus in group H40 showed no significant difference with the control P 〉0.05 ）, but was significantly higher than that of other groups P 〈0.05 ）. Moreover, except group H40, the feed coefficients of all other groups were significantly higher than that in control group （P 〈0.05 ）. The M. anguillicaudatus in group 1-140 had the highest condition factor and COR and the lowest viscera index, all of which showed significant differences with the other replacement groups （P 〈0.05） but the difference with the control group was not significant （P 〉 0.05）. Thus, a proportion of 40% of the fish meal replaced with maggot meal in the mixed feed for the M. anguilli- caudatus could improve the growth performance and physique indexes of M. anguillicaudatus.

Comparative Nutritional Analysis on Fish Meal and Meat and Bone Meal of Harmless Treatment of Dead Pig Carcass

In order to explore the resource utilization of the harmless treatment product(pork meat and bone meal,abbreviated PM)of pigs died of non-communicable diseases,the general nutritional components and amino acid composition of PM and fish meal were determined and compared.The results showed that the contents of moisture,crude protein,crude fat and ash in PM and fish meal were 3.25%and 8.92%,66.65%and 66.67%,13.52%and 8.23%,18.25%and 21.50%,respectively.The contents of essential amino acids(EAA)in PM and fish meal were 19.94%and 22.35%,respectively.For PM and fish meal,the first limiting amino acid was Met(methionine)+Cys(cysteine),and the second limiting amino acid was Lys(lysine);their essential amino acid indexes(EAAI)were 66.60 and 77.04,respectively;and their delicious amino acid(DAA)contents were 26.89%and 23.15%,respectively.In summary,the meat and bone meal of pigs died of non-communicable diseases has the characteristics of high protein and low ash contents,and has certain development and utilization potential as a recycled waste resource,especially in aquatic feed to replace fish meal.

Amino acid fortified diets for weanling pigs replacing fish meal and whey protein concentrate:Effects on growth,immune status,and gut health

Background： Limited availability of fish meal and whey protein concentrate increases overall feed costs. Availability of increased number of supplemental amino acids including Lys, Met, Thr, Trp, Val, and lie allows replacing expensive protein supplements to reduce feed costs. This study was to evaluate the effect of replacing fish meal and/or whey protein concentrate in nursery diets with 6 supplemental amino acids on growth performance and gut health of post-weaning pigs. Treatments were 1） FM-WPC： diet with fish meal （FM） and whey protein concentrate （WPC）; 2） FM-AA： diet with FM and crystalline amino acids （L-Lys, L-Thr, L-Trp, DL-Met, L-Val, and L-lie）; 3） WPC-AA： diet with WPC and crystalline amino acid; and 4） AA： diet with crystalline amino acid. Results： Pigs in FM-AA, WPC-AA, and AA had greater （P 〈 0.0.5） ADG and gain：feed than pigs in FM-WPC during wk ] （phase 1）. Plasma insulin concentration of pigs in AA tended to be greater （P = 0.064） than that of FM-WPC at the end of wk 1 （phase 1）. Plasma concentrations of IgG in AA was lower （P 〈 0.05） compared with WPC-AA and FW, and FM-AA had lower （P 〈 0.05） IgG concentration than WPC-AA at the end of wk 1 （phase 1）. Concentration of acetate in cecum digesta in FM-AA tended to be greater （P = 0.054） than that of FM-WPC and WPC-AA. Concentration of isovalerate in cecum digesta of pigs in FM-AA was greater （P 〈 0.05） than that of FW and WPC-AA. Conclusions： This study indicates that use of 6 supplemental amino acids can replace fish meal and/or whey protein concentrate without adverse effects on growth performance, immune status, and gut health of pigs at d 21 to 49 of age. Positive response with the use of 6 supplemental amino acids in growth during the first week of post-weaning may due to increased plasma insulin potentially improving uptake of nutrients for protein synthesis and energy utilization. The replacement of fish meal and/or whey protein concentrate with 6 supplemental amino acids could decrease the crude protein level in nursery diets, and potentially lead to substantial cost savings in expensive nursery diets.

Fish Meal Lecithin as Alternative Precursor of Docosahexaenoate and Choline

Choline and docosahexaenoate (DHA) are essential nutrients for maintaining normal brain function. However, their existence in fish lecithin is ignored and excluded during the degumming step of conventional fish oil manufacturing process. The study aims to introduce fish lecithin as alternative precursor of choline and omega-3 fatty acids especially DHA for nutritional supplements. Four grades of Thai fish meals with protein contents ranging from 60-70% were used. Their lipid characteristics were examined. Fish meal's fats and lecithln were 9-15 and 2-3 g/100 g, respectively. Total fatty acids constitute 23-27% monoenes without erucic acid and 24-28% polyenes including 15-19% DHA. Lecithin with 50% purity was prepared from grade-1 fish meal by means of consecutive methanol/nhexane/acetone extraction. The obtained lecithin contains choline upto 66-70 mole% with DHA reaches to 20-23%. Its peroxide value of 57 and acid value of 9 are accepted for food grade leclthin preparation, however, the further refinery process is still suggested. Since the world consumption of nutritional supplement foods is increasing steadily, the results of our study implies that fish lecithin is probably a promising source of choline and omega-3 fatty acids especially DHA for such an objective

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 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.

A Study on the Meat and Bone Meal and Poultry By-product Meal as Protein Substitutes of Fish Meal in Practical Diets for Litopenaeus vannamei Juveniles

A study was conducted to evaluate the effects of meat and bone meal (MBM) and poultry by-product meal (PBM) as the replacement of fish meal in the diets on the growth performance, survival and apparent digestibility coefficients (ADC) of Litopenaeus vannamei. The basal diets were formulated with 22% fish meal and other ingredients which provided about 40% protein and 9% lipid in the diet. The experimental diets included MBM or PBM to replace 0, 20%, 40%, 60% and 80% of total fish meal respectively. All diets were iso-nitrogenous and isocaloric in gross terms. The results showed that there were no significant differences (P>0.05) in growth performance and ADC among the treatments fed with the diets in which 0-60% fish meal had been replaced with MBM, while the percent weight gain (WG, %), body length gain (BLG, %) and ADC significantly decreased when the MBM was up to 80% of the fish meal. There were no significant differences (P>0.05) in growth performance and ADC among all the treatments fed with the diets in which 0-80% fish meal had been replaced with PBM.

Effects of probiotic bacteria on survival, growth and body composition of rainbow trout (Oncorhynchus mykiss) larvae fed diets with various fish meal

Objective:To compare the the effects of the diets containing various fish viscera meal and effects of probiotic bacteria(Lactobacillus sp.,Bifidobacterium sp.and Streptococcus sp.)on the growth,survival and carcass composition of rainbow trout larvae.Methods:Twelve tanks consisting of triplicates for each treatment group were used.Triplicate groups of rainbow trout(176 mg bodyweight)were fed with three diets formulated with viscera meal(VM)derived from common carp(Cyprinus carpio),or VM derived from mullet(Liza saliens and Liza auratus)or commercial diet with in-tank probiotic respectively,and three diets without probiotic 4 times a day at 5%to 6%of body weight for 45 d.Rainbow trout larvae(average individual weight,176 mg)were randomly distributed with density of 4 fish/L into 18 fiberglass tanks.In probiotic treatments a blend of selected bacteria at 104 CFU/mL were added into rearing tanks four times a day.At the end of the 45-day experiment,growth performance,survival rates and carcass composition of larvae were determined.Results:The results indicated that change to probiotic diets significantly affect growth and survival of rainbow trout larvae(P<0.05).Rainbow trout larvae fed with commercial diet with in-tank probiotics showed the highest survival rates(98%),total weight(2226 mg)and specific growth rates(7.16%/d)among treatment groups.Conclusions:VM derived from common carp can successfully replace more than half of marine fish meal in formulated diets for rainbow trout.Use of in-tank blends of Lactobacillus sp.,Bifidobacterium sp.and Streptococcus sp.,can increase survival rates and specific growth rates in rainbow trout larvae.

大口黑鲈饲料营养需求及鱼粉替代研究进展

水产养殖动物的精准营养需求参数对其配合饲料的优化或者开发至关重要。文章概述了大口黑鲈蛋白质、脂肪、矿物质、碳水化合物以及维生素等主要元素需求以及蛋白源替代研究,对大口黑鲈饲料配制和降低成本等有重要的指导意义。

改进鱼类营养和饲料研究范式:从大口黑鲈和大黄鱼配合饲料在养殖生产中的应用谈起

鱼类营养和饲料研究起始于20世纪50年代,并借鉴对人类和畜、禽营养研究的经验建立了研究范式。在过去70年中,鱼类营养和饲料研究遵循已有的范式取得了大量的成果,这些研究成果推动了水产配合饲料技术的进步,为水产饲料产业从无到有、从小到大做出了贡献。然而,随着全球水产养殖规模的不断扩大,水产养殖产业面临的资源和环境压力日益增加,对水产饲料也提出了更多和更高的要求。养殖生产实践表明,根据一些肉食性鱼类营养和饲料研究结果设计配方生产的饲料不能取得预期的应用效果,这意味着遵循已有研究范式所得到的结果难以完全满足现代鱼类养殖生产的需要。本文总结了两种具有重要经济价值的肉食性鱼类(大口黑鲈和大黄鱼)配合饲料在养殖生产中应用的曲折历程,指出早期研究明显低估了饲料蛋白水平是导致配合饲料长期无法在养殖生产中成功应用的主要原因。早期研究报道大口黑鲈的饲料蛋白需求为400~440 g/kg,大黄鱼的饲料蛋白需求为450~470 g/kg,但投喂配合饲料的鱼的生长明显比投喂冰鲜鱼的鱼慢。重新评估发现大口黑鲈和大黄鱼饲料蛋白需求分别为480~510 g/kg和490~520 g/kg,投喂含适量蛋白的配合饲料时鱼生长与投喂冰鲜鱼时接近。对大口黑鲈和大黄鱼饲料蛋白需求的明显低估反映出已有鱼类营养和饲料研究范式中存在不足,其表现为:①强调食物对鱼类生长的影响,但忽视了鱼类遗传背景和食物外的其他环境条件对鱼类生长和摄食的作用;②强调鱼类个体生长可反映其营养需求和饲料质量,但忽视了鱼类个体生长并不能完全反映养殖产量和效益;③强调生长和饲料利用效率在评价水产养殖效益方面的重要性,但忽视了投饵养殖对自然资源和环境所产生的负面影响是限制水产养殖可持续发展的瓶颈;④基础饲料配方对评价营养需求或饲料质量的影响没有得到足够重视,因基础饲料组成不合理导致一些研究结果缺乏实际意义。针对上述问题,作者建议对已有范式的概念、理论和研究方法做如下改进:①重视鱼类遗传背景和食物以外的其它环境条件对鱼类生长的影响,明确鱼类生长潜力决定营养需求,而食物营养是实现生长潜力的条件;②重视食物中各种营养素之间的相互作用,明确不同饲料原料在配方的营养平衡中发挥不同的作用;③进行饲养实验时重视实验鱼种质和种群结构,重视对照组和处理组个体生长的差异幅度在判断处理效应方面的指示意义,重视饲料配方对自然资源和环境等制约水产养殖可持续发展的因素的影响。改进后的研究范式更符合现代水产养殖生产实际,遵循其开展研究获得的结果能够更好地指导饲料配方设计,所生产的配合饲料也能更好地应用于水产养殖生产。

棉籽蛋白替代鱼粉对斑点叉尾鮰生长性能、饲料利用和肠道组织结构的影响

试验旨在研究棉籽蛋白替代鱼粉对斑点叉尾鮰生长性能、饲料利用率和肠道组织结构的影响。设计鱼粉含量为100 g/kg的基础饲料,用棉籽蛋白分别替代基础饲料中0、20%、40%、60%、80%和100%的鱼粉配制成6组等蛋白饲料(D1、D2、D3、D4、D5组和D6组),饲养初始平均体重为(171±1)g的斑点叉尾鮰67 d。结果表明:与D1组相比,D5组和D6组的末均重和增重率显著降低,饲料系数显著增加(P<0.05);D3组、D5组和D6组的肝体比显著低于D1组(P<0.05);D6组肌肉粗蛋白含量显著高于D1组(P<0.05);各组斑点叉尾鮰存活率、肥满度、脏体比和肌肉的水分、粗脂肪和粗灰分含量均无显著差异(P>0.05);当棉籽蛋白100%替代鱼粉比例时,饲料的干物质表观消化率和蛋白质表观消化率显著下降(P<0.05),各组之间的脂肪表观消化率无显著差异(P>0.05);在肠道组织学中,棉籽蛋白替代鱼粉对肠道的绒毛高度和肌层厚度无显著差异(P>0.05)。综上所述,在鱼粉含量为100 g/kg的基础饲料中,棉籽蛋白可以有效替代60%的鱼粉不会影响斑点叉尾鮰的生长性能、饲料利用和肠道组织结构。

酶解棉籽蛋白替代鱼粉及添加单宁酸对斑点叉尾鮰生长性能和肠道健康的影响

试验研究了酶解棉籽蛋白替代鱼粉及添加单宁酸对斑点叉尾鮰(Ictalurus punctatus)生长性能和肠道健康的影响。设计鱼粉含量为10%的基础饲料,用酶解棉籽蛋白分别替代基础饲料中33.3%、66.6%和100%的鱼粉,并在100%替代组的基础上添加0.5 g/kg和1 g/kg的单宁酸,配制成6组等蛋白饲料(D1、D2、D3、D4、D5组和D6组),饲养初始平均体重为(172.6±1.6)g的斑点叉尾鮰67 d。结果表明:D4、D5和D6组的末体重和增重率较D1组显著下降(P<0.05),D4和D6组的饵料系数较D1组显著增加(P<0.05)。各组斑点叉尾鮰存活率、肥满度、肝体比、脏体比和肌肉常规成分组成均无显著差异(P>0.05)。斑点叉尾鮰后肠肠道微生物群落的优势菌群包括厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidota)、变形菌门(Proteobacteria)和梭杆菌门(Fusobacteria)。对比不同处理组发现,D4组的拟杆菌门相对丰度显著低于D5组(P<0.05),D4组的变形菌门相对丰度显著高于D1、D2和D5组(P<0.05)。各组斑点叉尾鮰肠道的组织结构和微生物多样性无显著差异(P>0.05)。综上所述,在鱼粉含量为10%的基础饲料中,酶解棉籽蛋白可以有效替代66.6%的鱼粉而不会对斑点叉尾鮰的生长性能和肠道健康产生负面影响,0.5 g/kg单宁酸能有效改善无鱼粉组斑点叉尾鮰的肠道微生物群落组成,但对生长性能没有提升效果。