Effects of ration level and feeding frequency on digestibility in juvenile soft-shelled turtle, Pelodiscus sinensis

The effects of ration level and feeding frequency on digestibility in juvenile soft-shelled turtle, Pelodiscus sinensis, were investigated. Four ration levels 1.5%, 2.5%, 4.0% and satiation （6.0% BW/d） were used. Apparent digestibility （AD） of dry matter （DMAD）, protein （PAD） and protein real digestibility （PRD） were significantly affected by ration level, but not by feeding frequency when the ration level was similar. However, the feeding frequency affected the AD, DMAD, PAD and PRD significantly when the turtles were fed to satiation. The relationship between fecal protein content （Y） and protein intake （At） can be expressed as a quadric equation： Y=-0.1742＋0.1476X-0.0003X^2 （r^2=0.876, n=27, F=93.92, P〈0.01）.

Effects of Dietary Soy Protein Concentrate on Growth, Digestive Enzymes Activities and Target of Rapamycin Signaling Pathway Regulation in Juvenile Soft-Shelled Turtle, <i>Pelodiscus sinensis</i>

Soft-shelled turtle, Pelodiscus sinensis is important aquatic species in China, and searching for alternatives protein resources to fish meal (FM)-based feeds in feed has become urgent and important for its sustainability development. The present study was conducted to assess the effects of dietary soy protein concentrate (SPC) on growth, digestive enzymes and target of rapamycin (TOR) signaling pathway of juvenile P. sinensis (4.56 ± 0.09 g). SPC was applied to replace FM protein at 0%, 15%, 30% and 60% (designated as T0, T15, T30 and T60, respectively), and each diet was fed to triplicate groups. The results showed that there was no significant difference in growth performance and feed utilization except of the turtles fed with T60 diet, of which showed poorer daily weight gain and feed conversion rate. The pepsin/trypsin and Na+-K+ ATP-ase activities decreased dramatically when SPC level increased, and lipase activities in liver and intestinal tract also showed decline tendency. However, amylase activities were unaffected. No significant differences were observed in TOR, S6K1 and 4E-BP1 genes mRNA expression level of TOR signaling pathway among the treatments. However, the relative phosphorylated level of these proteins decreased significantly when SPC level increased. The present study indicated that high SPC substitution level would suppress digestive enzymes and TOR signaling pathway proteins phosphorylated level and eventually result in growth reduction of P. sinensis.

Physiological responses in vitamin C system during hibernation in juvenile Chinese soft-shelled turtle Pelodiscus sinensis

Vitamin C (Vc) is an important antioxidant that helps turtles tolerating stressful environment. This work quantified changes in tissue Vc levels during winter hibernation in the soft-shelled turtle Pelodiscus sinensis , to reveal the stress response pattern of tissue Vc during hibernation and contribute basic data for turtle culture. We sampled juvenile soft-shelled turtles at pre-hibernation (17.0°C mud temperature;MT), during hibernation (5.8°C MT) and after arousal (20.1°C MT) in the field. The transcript levels of the gene encoding L-gulonolactone oxidase (GLO), the key enzyme for Vc synthesis, decreased significantly during hibernation. However, GLO activity did not match the GLO transcription patterns and remained stable during hibernation, and showed temperature-dependent kinetic characteristics. Vitamin C levels in the brain, liver, kidney, and spleen (but not muscle) all decreased significantly during hibernation, but recovered to pre-hibernation levels or even higher levels after arousal. The soft-shelled turtle endured 5 months of hibernation with no significant oxidative damage in most tissues, except in the spleen. Splenic Vc was nearly exhausted during hibernation, accompanied by a significantly elevated malonaldehyde (MDA) level. Although the high level of oxidative damage quickly decreased after arousal, the potential tissue damage in the spleen during hibernation might account for the weakened immune capacity of turtles after hibernation.

White-spot disease of Chinese soft-shelled turtles (Trionyx sinens) caused by Paecilomyces lilacinus

Chinese soft-shelled turtles （Trionyx sinens） in culture farms using an artificial warming system in Zhejiang, China, often show typical signs of white-spot disease such as white spots on their bodies, skin lesions, anorexia and eventually death. The sick turtles were mostly 5-80 g in weight. A suspected fungal pathogen was isolated from the sick turtles and verified as Paecilomyces lilacinus by sequence analysis of the internal transcribed spacer （ITS） of its ribosomal DNA （rDNA）. Detailed morphological examinations were also conducted to confirm the white-spot disease.

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.

Effects of acute cold exposure on oxidative balance and total antioxidant capacity in juvenile Chinese soft-shelled turtle,Pelodiscus sinensis

Acute cold exposure may disturb the physiological homeostasis of the body in ectotherms.To date,there has been no information on the effects of cold exposure on homeostasis of reactive oxygen species(ROS)or antioxidant defense response in the Chinese soft-shelled turtle,Pelodiscus sinensis.In this study,P.sinensis juveniles were acclimated at 28℃,transferred to 8℃ as cold exposure for 12 h,then moved back to 28℃ rewarming for 24 h.We measured the ROS level and total antioxidant capacity(TAC)in the brain,liver,kidney and spleen at 2 and 12 h cold exposure,and at the end of the rewarming period.Malonaldehyde(MDA)and carbonyl protein were used as markers of oxidative damage.Turtles being maintained simultaneously at 28℃ were used as the control group.Cold exposure did not disturb the ROS balance in all 4 tissues,while rewarming raised the ROS level in the brain and kidney of P.sinensis.Cold exposure and rewarming decreased the TAC in the brain,liver and spleen but did not change the TAC in the kidney.MDA and carbonyl protein levels did not increase during the treatment,indicating no oxidative damage in all 4 tissues of P.sinensis.Our results indicated that extreme cold exposure did not impact the inner oxidative balance of P.sinensis,but more ROS was produced during rewarming.P.sinensis showed good tolerance to the harsh temperature change through effective protection of its antioxidant defense system to oxidative damage.This study provides basic data on the stress biology of P.sinensis.

Discovery of virus pathogen from soft-shelled turtle Trionyx sinesis

THE soft-shelled turtle Trionyx sinesis, because of its nutritional and medicinal values,

Supplementation with turmeric residue increased survival of the Chinese soft-shelled turtle (Pelodiscus sinensis) under high ambient temperatures

Turmeric residue（TR）, containing residual levels of curcumin, is a solid by-product waste generated after the extraction and separation of curcumin from turmeric root. A feeding trial was conducted to evaluate the effects of TR on the survival of Chinese soft-shelled turtles（SSTs）, Pelodiscus sinensis, under a high ambient temperature. A total of 320 female SSTs were assigned randomly to two diets： basal diet（the control group, n=160） and an interventional diet supplemented with 10% TR（the TR group, n=160）. Our results demonstrated that supplementation of TR increased the SST survival rate by 135.5%, and superoxide dismutase（SOD） activity of SST liver by 112.8%, and decreased the malondialdehyde（MDA） content of SST liver by 36.4%, compared to the control group. The skin of the SST fed TR showed a golden color. High-performance liquid chromatography（HPLC） analysis indicated that the concentrations of curcumin in TR and the skin of the SST fed TR were（1.69±0.30） and（0.14±0.03） μg/g, respectively. Our observation suggests that supplementation of TR increased the survival rate of SST under high ambient temperatures. We speculated that the increased survival rate and tolerance at the high ambient temperature were associated with the anti-oxidation activity of curcumin from TR. Moreover, curcumin in TR could be deposited in SST skin, which made it more favored in the market of China. Our findings provide new knowledge and evidence to effectively reuse TR as a feed additive in animal and aquatic farming.

Division of Chinese soft-shelled turtle intestine with molecular markers is slightly different from the morphological and histological observation

The Chinese soft-shelled turtle(Pelodiscus sinensis)is a commercially important species in Asian countries.Knowledge of its nutritional requirements and physiology is essential for determining the appropriate content of the feed for this animal.However,the lack of functional characterization of the intestine of this turtle limits the understanding of its absorption and utilization of nutritional materials.To solve this problem,this work utilized anatomical and histological methods to characterize 9 segments sampled along the anterior-posterior axis of the intestine.Furthermore,9 genes,which have been well documented in the intestine division of mammals and fish,were employed to functionally characterize the 9 sampled segments.Our results suggest that regions covering from the starting site to S3(position at 29.9%of the total length from the starting of the intestine)are the equivalent of mammalian dedumonen,and those covering S4(40.2%)and S5(65.4%),posterior to S8(92.7%),are the equivalent of the mammalian ileum and the large intestine,respectively.As to the region spaning S6(81.3%)and S7(87.3%),its functional equivalent(small intestine or large intestine)may be variable and depends on the functional genes.This molecular characterization in relation to the division of the intestine of Chinese soft-shelled turtle may contribute to the understanding of the nutritional physiology of the turtle,and promote Chinese soft-shelled turtle production.

Medicinal Soft-Shelled Turtle

Ingredients:Whole soft-shelled turtle; Chinese wolf-berry fruit(Lycium Chinese), milk vetch membrane root(Astragalus membranaceus), Chinese angelica andAmerican ginseng--about 25g of

稚鳖赖氨酸营养的需要量

选择体重为（２２．６２±０．５２）ｇ稚鳖９０只，平均分成６组，分别饲喂含赖氨酸为１．４２、１．８７、２．２２、２．５７、２．９２和３．３２％的等能等氮半合成饵料，试验期４５ｄ。结果表明，赖氨酸缺乏会降低鳖的生活力，导致其食欲下降、生长受阻、体蛋白沉积下降、肝生长受阻和赖氨酸－α－酮戊二酸还原酶活力下降沙＜０．０１）；赖氨酸对鳖的增重、饵料系数、体蛋白沉积量和净沉积率、体赖氨酸沉积量和净沉积率、肝重／体重和肝赖氨酸－α－酮戊二酸还原酶活力影响极显著（Ｐ＜０．０１），并成极显著或显著二次回归关系（Ｒ２＝０．７６６７－０．９５９４－，Ｐ＜０．００５－０．０２）。根据这些指标确定的赖氨酸需要量差异不明显，稚鳖赖氨酸需要量为２．４０％或５．３２９·（１００ｇＣＰ）－１。尽管赖氨酸对摄饵量和肝重也有极显著影响（Ｐ＜０．０１），但是不呈显著二次回归关系（Ｒ２＝０．３７６６－０．５９９０，Ｐ＞００５）。

高活性干酵母对中华鳖非特异性免疫功能和抗病力的影响

报道了高活性干酵母对中华鳖(Pelodiscus sinensis)幼鳖非特异性免疫功能和抗病力影响的研究结果。试验共设6个组,在各组饵料中高活性干酵母的添加量依次为每千克体重0 mg(对照组)、600.0 mg(试验I组)、800.0 mg(试验Ⅱ组)、1 000.0 mg(试验Ⅲ组)、1 200.0 mg(试验Ⅳ组)和1 400.0 mg(试验Ⅴ组)。投喂30 d后,从每组中各取10只中华鳖幼鳖采血,测定了中华鳖幼鳖血液中白细胞的吞噬活性、血清中溶菌酶和补体活性;另从每组分别取30只中华鳖幼鳖用注射嗜水气单胞菌(Aeromonas hydrophila)的方法行人工感染,检测其抗病力。研究结果表明,各试验组中华鳖幼鳖血液中白细胞的吞噬活性均显著高于对照组。第Ⅰ和第Ⅱ组中华鳖幼鳖血清中溶菌酶活性与对照组之间没有显著性差异,而试验Ⅲ、Ⅳ组和Ⅴ组中华鳖幼鳖血清中溶菌酶活性均显著高于对照组。第Ⅱ、Ⅲ、Ⅳ和第Ⅴ组中华鳖幼鳖血清中补体活性与对照组之间存在显著差异,而第Ⅰ组与对照组之间无显著性差异。投喂高活性干酵母能增强中华鳖幼鳖对人工感染A. hydrophila活菌的抵抗力。研究结果证明在中华鳖幼鳖饵料中添加高活性干酵母的量以每千克体重1 200.0 mg左右为宜。

中华鳖幼鳖的能量代谢（Ⅰ）──水中呼吸及其与温度、体重的关系

测定了饥饿状态下中华鳖（Ｔｒｉｏｎｙｘｓｉｎｅｎｓｉｓ）幼鳖在水中的呼吸代谢及其与温度、体重的关系。体重１６～１５０ｇ的幼鳖在水温２８℃下的个体耗氧率Ｒ可表示为：ｌｇ（Ｒ／ｍＬ·ｈ－１）＝０．６３１４ｌｇ（Ｗ／ｇ）－１．０５４９（Ｗ为个体湿重）；ｒ＝０．９１，ｎ＝２６，Ｐ＜０．００１，这时幼鳖的单位体重耗氧率Ｖ与体重呈如下负相关关系：Ｖ＝８８．１２５４Ｗ－０．３６８６；ｒ＝０．８０，ｎ＝２６，Ｐ＜０．００１．中华鳖能够正常活动、摄食的温度范围为２０～３５℃。２０，２４，２６，２８，３０，３２，３５℃下３０～６０ｇ幼鳖水中呼吸耗氧率的变动范围为２４．３７～３１．２０ｍＬ·ｋ－１·ｈ－１．ｔ检验表明温度对鳖在水中的呼吸没有显著影响．

食物类型对平胸龟幼体摄食和消化影响的初步研究

在(25±1)℃水温下,以鱼肉、猪肉和配合饲料3种食物投喂平胸龟(Platysternon megacephalum)幼体,测定食物类型对其摄食、消化及饵料湿重转化率的影响。结果显示:食物种类不影响平胸龟幼体的摄入能,平均为139.3 J/(d.g),但显著影响幼龟的表观消化率、蛋白质和脂肪消化率以及饵料湿重转化率。其中,摄食配合饲料的表观消化率(91.9%)低于鱼肉(94.1%)和猪肉(94.7%),蛋白质消化率亦为配合饲料<鱼肉<猪肉,但配合饲料的脂肪消化率和饵料湿重转化率则显著高于鱼肉和猪肉。因此,从饵料湿重转化率及养殖效益考虑,配合饲料优于鱼肉和猪肉。

稚、幼鳖饲料配方的研究

设计了９种稚、幼鳖饲料，共进行４次饲养试验。软颗粒饲料（自然干燥，含水率约１０％）可以取得极高的饲料利用率，获得１０００ｇ鳖肉仅需耗费饲料蛋白５７０ｇ，远优于市售商品饲料１２００ｇ的值。唯稚鳖对其嗜好性差，摄食量少，致生长速度缓慢。以国产鱼粉和秘鲁鱼粉（均为褐色鱼粉）作为主要蛋白源加工成的软颗粒饲料和粉状饲料（制成面团）均未取得好的饲养效果。饲料中含有３８．７％的植物蛋白（豆粕、生物蛋白粉），同时减少鱼粉用量，稚鳖的生长和饲料效率这两个主要指标均有下降，但成本可大幅度降低，表明植物蛋白在饲料中应占有适当份额，比例过高并不适宜。生物蛋白粉的适口性优于豆粕。通过调整粘结剂的种类与数量等方法，可以较大幅度地改变现行鳖饲料的配方模式，达到提高水稳定性、降低成本并获取良好饲养效果的目的。本文报导的Ｄ和Ｂ１饲料即属这一类型，其试养实绩明显优于某品牌市售商品饲料。

粘稠性荚膜红假单胞菌对黄沙鳖稚鳖水质及生产性能的影响

通过对黄沙稚鳖养殖池进行pH值、DO、氨氮、亚硝酸盐和COD水质指标的测定和比较,探讨荚膜红假单胞菌对黄沙鳖稚鳖养殖池水质及生产性能的影响。结果表明:使用荚膜红假单胞菌后,试验池与对照池相比较,水体中的溶氧量提高了31.17%,pH值平缓波动,显著降低水中氨氮含量,下降幅度达74.08%,加快了水中氨氮转化量,减少了氨氮的毒害作用,成活率提高了9.5%,重量增加了9.79kg,发病率降低30.33%,治愈率高达19.5%。

工厂化养殖稚幼中华鳖的环保型温室构建与性能试验

为了满足稚幼中华鳖工厂化养殖的需求,响应减少CO_2排放的政策,设计建造了符合其生活习性的环保型温室。该温室使用地源热泵空调系统控温,底部排污系统排出残饵和排泄物,养殖池内配置网片隐蔽巢供稚幼鳖栖息,采用微孔增氧装置和微生物制剂调控水体中溶解氧、氨氮和亚硝态氮含量。结果表明通过使用地源热泵空调,1栋占地780 m2的温室在10个月的生产期内减少使用燃煤约35 t,减少CO_2排放约84.01 t。养殖水体中溶解氧质量浓度5.83~7.68 mg/L,氨氮和亚硝态氮质量浓度分别在0.39~0.83 mg/L和0.14~0.16 mg/L范围内。经过约10个月的养殖(放养质量约为3.5 g,密度为50只/m2),平均质量为581 g,存活率86.2%,饲料转化率1.18,特定生长率1.77,1栋温室年利润为157 870元。综上,该工厂化养殖稚幼鳖的环保型温室能为其提供舒适的生活环境,表现出良好的经济效益和社会效益,有很大的推广价值和实际意义。

人工提前破壳对中华鳖(Trionyx siensis)卵的孵化和稚鳖生长的影响研究

对恒温孵化人工统一提前破壳与自然出壳的中华鳖稚鳖的生长发育进行了实验比较,试验在记录积温28800~30000℃时人工提前统一破壳,结果表明：人工提前统一剥壳对中华鳖存活率和稚鳖的体质无不良影响,经30天养殖的稚鳖苗达到一级标准,其生长比速、生长指标指标与自然出壳的中华鳖稚鳖差异不显著（P〈0.05）;而生长常数、特定生长率、生长系数指标则显著优于同期受精和孵化的自然出壳稚鳖（P〉0.01）。人工破壳的稚鳖比同时受精、同批孵化及延迟十天产出的受精卵自然出壳较迟的对照稚鳖具有明显的生长优势;人工提前破壳稚鳖的生长系数（W末重/W始重）分别为2.932±0.094、2.808±0.074,与同批自然出壳较迟的对照差异达到21.47%~45.9%,达极显著水平（F=124.6〉F0.01）;人工提前破壳稚鳖养殖的特定生长率分别为1.5365±0.1532、1.4777±.1325,与自然出壳较迟的对照的特定生长率差异达极显著水平（F=68.5〉F0.01）;人工提前破壳稚鳖养殖的生长常数分别为0.112±0.001、0.107±0.002,与与自然出壳较迟的对照差异达146.5%~302.7%,达极显著水平（=1684.5〉F0.01）。人工提前破壳孵化的稚鳖具备摄食强度大、抗逆性强、不易感染病虫害等优势,可为周年养殖稚鳖的生长赢取时间,是培育大规格稚鳖、缩短养殖周期,提高中华鳖养殖经济效益的有效途径。

包膜赖氨酸对稚鳖生长性能的影响及机理探讨

试验选择平均体重为18.40 g稚鳖180只,分为3组(每组6个重复,每重复10只),分别饲喂赖氨酸缺乏的(赖氨酸水平1.51%),添加晶体赖氨酸和包膜赖氨酸(赖氨酸水平均为2.62%)等能等氮半合成饵料,试验期60d。结果表明,赖氨酸缺乏组鳖晒背率、惊吓逃跑率、特定生长率、肝脏赖氨酸-α-酮戊二酸还原酶活性较低,腐斑率和饵料系数高。添加包膜赖氨酸显著提高了鳖生活力,特定生长率和蛋白质效率,且作用效果优于晶体赖氨酸。赖氨酸缺乏组和晶体赖氨酸组鳖摄食后6 h内血清游离赖氨酸在2 h左右达到高峰水平,而包膜赖氨酸组在4 h左右达到高峰水平。说明包膜赖氨酸可延缓血清游离赖氨酸达到高峰浓度的时间,促进氨基酸的有效利用和蛋白质的合成。

稚鳖控温养殖试验

个体均重5.1克的幼鳖,控温饲养150天,平均重达104.1克,日平均增重0.694克,成活率91.1%,单产2.14kg/m^2.