Digestibility of Glandless Cottonseed Protein in Diets for Pacific White Shrimp,Litopenaeus vannamei

Accurate digestibility coefficients for protein, energy, and lipid are needed by feed formulators to optimize diets to meet nutritional requirements and to substitute ingredients cost‐effectively. Of particular interest is protein, which accounts for the majority of shrimp feed content and expense. The current study evaluated seven cottonseed meal and protein products. Most of the samples were derived from a glandless cotton variety that lacks significant levels of the antinutritive compound, gossypol. The various protein fractions were evaluated for apparent crude protein, crude lipid, and energy digestibility when fed to juvenile Pacific White Shrimp, Litopenaeus vannamei. Apparent energy digestibility for the protein fractions derived from the glandless seed ranged from 76.7% for ground kernels to 94.6% for protein isolate, and these values were greater than the value obtained for the commercial meal that contained gossypol (64%). Apparent protein digestibility for the six glandless‐cotton‐based samples varied from 72.3% for the ground full‐fat kernels to 94.1% for the protein isolate, and these values were mostly higher than the value obtained for the commercial meal (82.3%). The high apparent digestibility values demonstrate that low‐gossypol cottonseed protein products may be useful as a cost‐effective replacement for more expensive protein sources in L. vannamei diets.     

Efficacy of Three Methionine Sources in Diets for Pacific White Shrimp, Litopenaeus vannamei

Abstract.— To examine the need for supplemental dietary methionine and to determine the ability of different methionine sources to meet this need for Pacific white shrimp, Litopenaeus vannamei, a growth trial was conducted. A control diet (30% crude protein) was formulated to be deficient in methionine by inclusion of high levels of dehulled, solvent‐extracted soybean meal and with no fish meal (methionine level was 0.45% of diet as fed, 1.5% of total amino acids). Three test diets were manufactured based on the control diet but supplemented with l ‐methionine, dl ‐methionine, or an analog of methionine (2‐hydroxy‐4‐methylthio butanoic acid [HMTBA], calcium salt) at the level of 0.5% as fed (equivalent to 1.5% of total amino acids). Cystine was constant among these diets at 0.5% of diet as fed. A commercial feed (30% crude protein) was included as a reference. The culture vessels were flat‐bottomed, cylindrical, black fiberglass tanks (1.5‐m diameter) initially filled with 1000 L seawater and supplied with aeration and seawater from a well at a rate of 2 L/min. At the end of the trial, all surviving shrimp were counted and weighed. The trial was run outdoors, with a mean water temperature of 25.9 C. The mean survival, final weight, growth rate, and feed efficiency of shrimp in the control group were 95.9%, 10.8 g, 0.93 g/wk, and 0.44 g/g, respectively. The mean values of all the test treatments were 96.9%, 11.6 g, 1.00 g/wk, and 0.47 g/g, respectively. The final weight and growth rate of shrimp fed the control diet were significantly lower than those of shrimp fed the methionine‐supplemented diets, indicating that this species has a requirement for dietary methionine. There were no significant differences (P > 0.05) in any of the parameters among the test treatments, indicating that l ‐methionine, dl ‐methionine, and HMTBA can be used to meet the methionine requirement of this species under these experimental conditions. It is concluded that the three sources of methionine examined in this trial, l ‐methionine, dl ‐methionine, and HMTBA, are similar in their ability to meet the methionine requirement of this species.     

蜡样芽孢杆菌对凡纳滨对虾幼体变态的影响

研究了1株蜡样芽孢杆菌zou8对数期细胞对凡纳滨对虾无节幼体Ⅲ期到溞状幼体Ⅱ期幼体变态的影响;并通过zou8与弧菌的平板拮抗、共培养试验探讨其促进幼体变态的机制是否与拮抗病原弧菌有关。结果表明:高数量zou8细胞对凡纳滨对虾无节幼体Ⅲ期到溞状幼体Ⅱ期幼体的变态具有极显著(P<0.01)促进作用,尤其是多次加菌;zou8促进幼体变态作用的发挥并非通过产生拮抗物质直接抑制病原弧菌,而是通过其他可能机制。     

植物乳酸杆菌对凡纳滨对虾生长、消化酶活性和肠道组织形态的影响

将体质量(8.10±0.13)g的凡纳滨对虾放养在室内500L玻璃纤维水桶中,以不同剂量(0、0.5%、1.0%和2.0%)的植物乳酸杆菌菌液(密度109 cfu/mL)拌料投喂,观察凡纳滨对虾的生长、消化酶活性和肠道组织结构的变化。结果显示,投喂15d后,0.5%和1%菌液组对虾的平均体质量、质量增加率和特定生长率均显著高于对照组(P0.05),饲料系数显著降低(P0.05);0.5%菌液组对虾肝胰腺消化酶和肠道消化酶活性显著增强(P0.05),对虾肠上皮细胞高度显著增加(P0.05)。研究结果表明,投喂0.5%植物乳酸杆菌可显著提高凡纳滨对虾消化酶活性和肠上皮细胞高度,促进对虾生长。     

Oleous Extraction of Carotenoids from Shrimp Cephalothorax and its Effect on a Microencapsulated Diet with Nauplii Larvae

ABSTRACT

Carotenoids were oil extracted from shrimp-cephalothorax meal at two meal:oil ratios (1:5 and 1:10) and two meal-particle sizes (0.150 and 0.150–0.177 mm). Extraction results were significant at 0.150 mm in particle size and a meal:oil ratio of 1:10, obtaining 286 mgL^?1 of pigments. Pigmented oil was microencapsulated to reduce deterioration by spray drying using two encapsulating blends: Mesquite gum-whey-protein concentrate and Arabic gum-mesquite gum-maltodextrin 10 DE. Microcapsule morphology and thermo-oxidative stability were evaluated. The Arabic/mesquite gum blend showed the best morphology and stability. A bioassay using Litopenaeus vannamei nauplii was performed using microalgae as a control. Results indicated that pigmented oil microcapsules increased the survival percentage when compared with the control. Larvae growth evaluated as the exoskeleton length was significantly different from the control favoring the pigmented oil diet. Larvae behavior measured as DI and PLI_c showed no significant differences among the two treatments and the control.     

人工基质对凡纳滨对虾免疫和消化相关指标的影响

将体长1cm的凡纳滨对虾饲养于池底铺有黑膜的400m2圆形高位池中,池中沿水流方向与池底垂直悬挂由40目双层筛绢网制成的人工基质(间距约1m),其中基质与池底面积之比约为1∶2,常规饲养,分别于养殖第29、57d和80d测定对虾肝胰腺中总抗氧化能力、溶菌酶、诱导型一氧化氮合酶、淀粉酶和胃蛋白酶活性以及一氧化氮含量的变化,研究人工基质对肝胰腺免疫和消化相关指标的影响。试验结果显示,养殖第29d,基质添加组对虾的免疫酶活性均显著高于对照组(P0.05),消化酶活性变化不显著(P0.05);养殖第57d(台风期间),基质添加组对虾各免疫指标和淀粉酶活性均显著低于对照组(P0.05);养殖第80d(台风过后26d),基质添加组对虾总抗氧化能力、诱导型一氧化氮合酶、淀粉酶和胃蛋白酶活性显著升高(P0.05)。研究表明,人工基质可以显著影响对虾免疫和消化机能,而基质生物膜系统遭台风等强天气干扰破坏后仍具有一定的自我修复能力。     

氨氮促使携带白斑综合症病毒凡纳滨对虾发病及其血细胞、酚氧化酶和过氧化氢酶变化

通过白斑综合症病毒(WSSV)感染得到携带WSSV病毒的凡纳滨对虾,它们由0.05 mg/L氨氮水体进入不同氨氮浓度水体,在7 d内,1.75 mg/L,2.25 mg/L,3.00 mg/L氨氮水体内个体发生病毒病,并产生死亡。在14 d内,0.75 mg/L氨氮以及大于这一浓度水体内个体发生病毒病,并产生死亡,其中3.00 mg/L氨氮水体内死亡100%,2.25 mg/L氨氮水体内死亡80%,1.75 mg/L水体内死亡60%。在0.35 mg/L氨氮水体,7-14 d内对虾开始发病,没产生死亡。发病个体血细胞数量下降迅速,血清酚氧化酶先增高再迅速下降,其中3 mg/L氨氮水体中的携带病毒对虾只有下降。同时氨氮浓度越大,携带病毒凡纳滨对虾血清过氧化氢酶活力下降越快,越多。     

硒源对凡纳滨对虾生长、体组成和抗氧化能力的影响

水温(29.0±1.3)℃,将初始体质量(0.41±0.01)g的凡纳滨对虾随机分为4组,每组3个重复,饲养在室内循环水养殖系统中,投喂基础饲料(对照组)及在此饲料中分别添加硒含量相等(0.30mg/kg)的亚硒酸钠、酵母硒和蛋氨酸硒的4种饲料,养殖56d,比较了不同硒源对凡纳滨对虾生长、体组成和抗氧化能力的影响。试验结果表明,蛋氨酸硒组对虾的生长性能显著高于对照组和亚硒酸钠组(P0.05)。外源硒可显著影响对虾体蛋白和脂肪含量(P0.05),蛋氨酸硒组对虾机体营养成分显著优于其他组(P0.05)。添加外源硒组对虾的血清总抗氧化能力和谷胱甘肽过氧化物酶活性显著高于对照组(P0.05)。蛋氨酸硒组对虾血清丙二醛含量显著低于其他组(P0.05)。由此得出,饲料添加0.3mg/kg的硒能在一定程度上提高凡纳滨对虾的生长和抗氧化能力,蛋氨酸硒优于酵母硒和亚硒酸钠。     

凡纳滨对虾商业苗种抗WSSV性能比较

白斑综合征病毒(WSSV)一直是甲壳类生物的高致病性病原。为了解市场上不同凡纳滨对虾(Litopenaeus vannamei)商业苗种病原携带情况及其抗WSSV性能,本研究收集了6个品牌的凡纳滨对虾商业苗种(分别简称为海南Z、海南S、广州P、广州Z、黄骅R和东营M),先进行包括WSSV在内的8种病原的检测,然后,采用单尾定量口饲感染方式进行抗WSSV性能测试,并比较各组苗种感染WSSV后的平均存活时间、存活率以及累积死亡率的差异。结果显示,6个商业苗种都不携带WSSV,部分苗种检测有潜在虾肝肠胞虫(EHP)和偷死野田村病毒(CMNV)。各苗种感染WSSV后,平均存活时间从长到短依次为海南Z、广州P、黄骅R、海南S、广州Z、东营M。东营M感染WSSV后第4天达到死亡高峰,而海南Z在第6~7天到达死亡高峰,比东营M晚了2~3d。感染实验结束后,海南Z和广州P存活率最高,同为72.5%,而东营M和黄骅R的存活率最低。本研究表明,海南Z和广州P抗WSSV性能最强,研究结果可为凡纳滨对虾抗病新品种的选育提供基础数据。     

Dual Benefits of Whey Protein Concentrate in a Microencapsulated Diet for Larval White Shrimp, Litopenaeus vannamei

Abstract— In this work a larval shrimp diet was spray-dried using a ratio of 75% whey protein concentrate and 25% mesquite gum as wall material, where the sole protein contribution to the diet was the whey protein concentrate. The microencapsulated diet exhibited the following physical properties: mean volumetric particle size of 49.3 om, characteristic floatability time 225.3 min, and density of 606 g/L. Its outer morphology was characterized by a dimpled spherical shape with no evident surface pores or cracks. Inner microstructure showed a central void, with the feed components finely embedded in the wall matrix. Two bioassays were performed with zoea of white shrimp Litopenaeus vannamei . In the first study, microencapsulated diet, and microencapsulated diet plus a single dose of live algae, were compared with a live algae control diet; in the second study, three co-feeding regimes consisting of microencapsulated diet + 10,30 and 60C. muellericellaL, respectively, were compared with the live algae control diet. In overall terms, the co-feeding regime with 30 cells/ OL produced larvae with carapace length (0.74-mm CL) and development index (4.5 DI) significantly superior to that of the live algae treatment (0.70-mm CL, 4.1 DI; respectively), and yielded similar individual dry weight (34-Og DW) and survival rate (58%). These results indicate that microencapsulated diets supplemented with live algae can produce responses similar to those of live feed. These results     

Influence of Algal Exudates and Bacteria on Growth and Survival of White Shrimp Larvae Fed Entirely on Microencapsulated Diets

Intact microencapsulated protozoeal diets (MED), added to 5 m filtered hatchery water at the recommended concentration of 4 mg L^-1 gave no significant difference in bacterial numbers after 6 h, over a 48 h period compared to control groups in autoclaved hatchery water. Disruption of the MED resulted in a significant increase in bacterial numbers up to 12 h compared to controls with intact microcapsules. Protein leach rates were similar in sterile water and 5 m filtered water, indicating that leaching was independent of microbial activity. MED leached significantly less dietary solubles compared to a microparticulate diet (MPD). There was no evidence to suggest significant attachment of bacteria to diet particles for at least 48 h.In low-quality water after algal blooms, survival of white shrimp (Penaeus indicus) larvae was poor when reared in both sterile and 5 m filtered water. The addition of bacteria filtered from xenic algal cultures together with the algal exudates to such water gave significant improvements in survival to larvae fed MED in 5 m filtered water but not in autoclaved culture water. Live algal diets promote high larval survival and growth irrespective of the inclusion of bacteria.It is suggested that algal exudates act as selective bacteriocides and total replacement of algae with MED requires a balanced bacterial community which can be attained at times from natural sea water, or when the natural bacterial community balance is disturbed, corrected by the use of algal exudates.     

Use of Grain Distillers Dried Yeast in Practical Diets for Juvenile Pacific White Shrimp,Litopenaeus vannamei

Grain distillers dried yeast (GDDY) is a yeast‐based protein source that is obtained from the bioethanol industry. A range of yeast‐based products has been evaluated as nutritional supplements in fish diets, yet there is limited information in shrimp. Therefore, the objective of this study was to evaluate the production response of Litopenaeus vannamei fed diets containing increasing levels of GDDY in two growth trials. In trial 1, five diets formulated to contain 360 g/kg crude protein, 80 g/kg lipids, and up to 300 g GDDY/kg were evaluated under laboratory conditions with juvenile shrimp (1.90 ± 0.10 g, initial weight). In trial 2, juvenile shrimp (0.40 ± 0.01 g, initial weight) were fed similar diets where lysine was supplemented in diets with high levels of GDDY (200 and 300 g/kg of diet). The results from this study demonstrate that inclusion of GDDY up to 300 g/kg of diet did not cause negative effects on final biomass, mean final weight, feed conversion ratio, and survival. Furthermore, the addition of lysine to diets with high levels of GDDY (200 and 300 g/kg of diet) did not enhance growth performance under the reported conditions, confirming lysine was not limiting. Consequently, these results indicate that up to 300 g GDDY/kg of diet can be used in practical diets for L. vannamei in a clear water system.     

The Influence of Artemia and Algal Supplements during the Nursery Phase of Rearing Pacific White Shrimp, Litopenaeus vannamei

A 21‐d nursery trial was conducted to evaluate various food supplements on growth and survival of postlarval (PL) Litopenaeus vannamei. Each of four treatments was provided with an equal quantity of a dried commercial feed throughout the study. Three treatments received algae paste (Thalassiosira weissflogii) supplemented every 3 d. These include F, commercial feed plus algae; FAr3, commercial feed plus algae plus Artemia every other day during the first 7 d; and FAr7, commercial feed plus algae plus Artemia every day during the first 7 d. The fourth treatment served as control (FNA); it relied only on the commercial feed plus naturally occurring algae. At the conclusion of the nursery period, there were no significant differences in survival or feed conversion ration for PL nursed in the various treatments. Artemia did have some effect in that PL receiving Artemia supplement for 3 d (FAr3) were significantly larger than those that did not. Algal paste in itself had no significant effect. Overall, results suggest an advantage to supplementing dried feed with Artemia for at least 3 d during the first week of nursery culture but little advantage to the use of a diatom paste as a food supplement.     

Co-Feeding of Pacu,Piaractus mesopotamicus Holmberg (1887), Larvae with Artemia Nauplii and a Microencapsulated Diet

Abstract

Aiming at a precocious substitution of live prey by artificial diet, a 20-day experiment with pacu, Piaractus mesopotamicuslarvae using co-feeding and abrupt weaning strategies was set up. At the end of the experiment, larvae fed Artemia showed the best results (P < 0.05) in weight, total length and biomass, compared with other treatments. Larvae fed exclusively a microencapsulated diet never ingested the diet. Diet ingestion in co-fed and abrupt-weaned larvae was low, but did increase during the experiment; however, Artemia influenced diet ingestion on co-fed larvae. Careful considerations should be given to diet processing and formulation to ensure survival and growth of larvae fed exclusively on prepared diets.     

不同饵料对奥尼罗非鱼仔稚鱼生长发育及消化酶活力的影响

将初始体质量为(0.006±0.0005)g的仔鱼,随机分为4组,每组3个平行,分别投喂4种饵料:人工配合饵料、轮虫、蛋黄和轮虫+人工配合饵料.试验周期为28 d.结果表明,(1)轮虫+人工配合饵料和人工配合饵料组生长较快,特定生长率分别为0.014 %/d和0.013 %/d, 绝对生长率达到0.150、0.142 g/d,二组差异不显著(P>0.05);蛋黄组生长最慢,与其他各组差异显著(P<0.05).(2)轮虫+人工配合饵料与轮虫组仔稚鱼的成活率达到90.3%和 89.7%,大部分个体发育进入幼鱼阶段,二组差异不显著(P>0.05);蛋黄组存活率较低,只有40.7%,与其他各组差异显著(P<0.05).(3)投喂不同饵料对奥尼罗非鱼仔稚鱼的消化酶具有显著影响,蛋黄组的淀粉酶和脂肪酶活力显著高于其他各组(P<0.05);轮虫+人工配合饵料组的胃蛋白酶活力较高,天然饵料(轮虫)组较低.     

凡纳滨对虾饲料添加剂的研究进展

凡纳滨对虾(Litopenaeus vannamei)俗称南美白对虾,是目前世界养殖产量最高的三大虾种之一,具有对水环境抗逆能力强、营养要求低、生长速度快,虾体含肉量大、肉质鲜美、营养丰富等诸多优点,自1998年来,在广东、广西、海南等省(区)广为     

海洋仔鱼消化酶变化及饵料的影响

近年来海洋仔鱼消化系统,包括胃、肠道以及胰脏发育的研究进展进行了综述,描述了其消化系统在发育过程中形态和功能的变化,对仔鱼发育过程中包括胃蛋白酶、胰酶、肠酶及其他消化酶的变化以及饵料组分的影响进行了总结。     

Effect of Diet Size on Feeding Behavior and Growth of Pacific White Shrimp,Litopenaeus vannamei

Abstract

Six diet sizes, manufactured from crumbling large pellets, were investigated for their effect on the feeding behavior and growth of Pacific white shrimp, Litopenaeus vannamei. These diets containing 44.7% protein and 8.2% lipid were fed to 0.9 g shrimp for a period of eight weeks under indoor controlled laboratory conditions. Shrimp were stocked at a density of 12 animals per 52 L aquarium (50/m²) and were evaluated for feeding behavior, final weight, growth rate, feed conversion ratio (FCR), and survival. Feeding behavior was observed weekly starting at the beginning of the 4th week until the end of the trial. Results indicated that the variation in diet sizes did not produce significant differences in shrimp growth, FCR or survival. However, shrimp feeding behavior (in terms of total attacking incidents during feeding) was significantly different among diet sizes. This shrimp behavior was observed more frequently in aquaria fed larger diet size (3.0 mm pellet) as compared with those fed smaller diet sizes (0.7 mm and 1.2 mm crumbles). When shrimp were fed larger pellets, some of the individuals obstruct other individuals and monopolize the diet. Such “selfish” behavior of shrimp could result in considerable size variation and severe mortality of smaller individuals, which could be the case when shrimp are reared to market size. The effect of diet size on shrimp feeding behavior deserves further investigation and the use of a continuous monitoring device such as a video camera is strongly recommended. Future study should also consider various shrimp and pellet sizes more meaningful to aquaculture producers.     

Use of Porcine Meal in Plant‐based Practical Diets for Pacific White Shrimp,Litopenaeus vannamei

Two growth trials were conducted to evaluate and confirm the efficacy of a porcine meal (PM) with high protein content (>90%) as an alternative feed ingredient in commercial‐type feed formulation for Pacific white shrimp, Litopenaeus vannamei. Six experimental diets were formulated for the two growth trials. The first five diets contained increasing levels (0, 1, 2, 4, and 6%) of PM as a replacement for soybean meal in a plant‐based diet with low inclusion level (6%) of fish meal (FM). The last experimental diet was produced utilizing 4.2% PM to completely replace FM. In Trial 1, shrimp (1.5 g initial mean weight, 20 shrimp/tank, n = 4) were offered test diets for 6 wk in a semirecirculation system. At the end of Trial 1, shrimp fed with the diet containing 6% PM exhibited significantly enhanced weight gain (WG), feed conversion ratio (FCR), and survival compared to those fed with the diet devoid of FM. As survival was poor across all treatments and different densities could mask growth results the trial was repeated. In Trial 2, shrimp (0.85 g, 15 shrimp/tank, n = 4) were offered diets for 6 wk. Dietary supplementation of PM at 6% significantly improved WG, FCR, and apparent net protein retention in contrast with the treatment devoid of FM, confirming the same trends in Trial 1. No significant difference was detected in protein, lipid, moisture, and mineral profiles of whole‐body shrimp as well as survival across all the treatments. Results of this study indicate that PM is a good high protein source in shrimp feeds, which can be included up to 6% in the low FM‐based diet without compromising the growth of shrimp.