辽东地区南美白对虾淡水池塘养殖技术

南美白对虾具备生长快、个体大、肉质多、适应能力强的特点,现已成为辽东地区淡水池塘养殖的理想品种,但南美白对虾的养殖具有一定风险,需要较高的养殖技术水平才能获得好的收益。为此,本文从池塘准备、虾苗放养、日常管理、虾病预防、及时收获、淡化培育、半封闭养殖等方面介绍了辽东地区南美白对虾淡水池塘养殖技术要点,希望能够为南美白对虾的养殖者们提供一些帮助。     

南美白对虾虾苗标粗养殖技术

天津市静海区地处华北平原北部,天津市西南部,池塘养殖是我区水产品生产的主要方式,养殖产量占水产品总产量的98％.90年代末,天津地区成功引进南美白对虾,由于静海区池塘土壤大部分为盐碱地,水质盐度为3～5‰,非常适合南美白对虾生长,套养南美白对虾成为静海区主要养殖模式;分别为以鲤鱼、鲫鱼为主套养南美白对虾,以虾为主套养草...     

南美白对虾养成期管理技术要点

南美白对虾亦称白脚,虾具有生长快、对饲料蛋白需求量低、肉味鲜美、抗病力强的特点,为当今养殖产量最高的三大优良虾种之一.该虾对盐度的适应范围广,经盐度驯化,可完全适应在淡水池塘中生活.     

南美白对虾在不同盐度中的营养需要

南美白对虾(Penaeusvannamei),又称为白对虾,是世界三大经济虾类之一,具有生长快、适应性强、食性杂、对食物营养要求不高、抗病能力强的特点。近几年来,特别是南美白对虾高位池养殖模式、淡水养殖模式获得成功后,在我国从南到北形成了南美白对虾养殖热潮。南美白对虾在不同盐度养殖情况下,对各种营养物质的需要量存在差别。所以,在配制南美白对虾饲料时应根据不同的盐度进行配制,才能获得营养物质的最大利用率。1南美白对虾在不同盐度中对蛋白质的需要量目前,对南美白对虾蛋白质需要的研究很多,但得出的结果相差较大。其主要原因是试验条…     

南美白对虾的养殖技术

南美白对虾具有广盐性、生长快、对水环境适应能力及抗病力强等特点,是沿海池塘养殖致富的好选择。近几年在我们东营沿海养殖区农户养殖南美白对虾的热情很高,但是由于部分养殖户没有掌握好养殖     

盐碱地区如何养殖南美白对虾

自2000年以来，北方地区成功引进南美白对虾，养殖获得成功，养殖面积逐年扩大，取得较好的经济效益。天津地区池塘盐碱化严重，盐度2％0～15％0以上，养殖用水多为生活污水，pH值、氨氮严重超标，水质不易调节；加上近一两年养殖户盲目加大养殖密度，养殖管理体系跟不上，以及南美白对虾种质退化，致使南美白对虾的养殖发生严重病害。2004年有的养殖户几乎绝收，造成惨重的经济损失。     

南美白对虾配合饲料初探

南美白对虾（Ｐｅｎａｅｕｓｖａｎｎａｍｅｉ）原产于太平洋沿岸 ,此虾生长快、对饲料蛋白需求量低、产肉率高、离水存活时间长、抗病力强 ,是迄今世界上养殖产量最高的虾种之一 ,它对盐度的适应范围广 ,经驯化可在淡水池塘中养殖 ,是海虾淡水养殖很有前途的一个新品种。近年来 ,国外对南美白对虾的饲料研究较多 ,在蛋白质需求、氨基酸平衡、维生素需求等方面都有较深的研究 ,表１是南美白对虾配合饲料中各种营养成分的推荐用量。１对蛋白质的需求Ａｎｄｒｅｗ等（１９９２）报道了白对虾的蛋白量为２８ %～３２ % ,但因为饲料蛋白源的品质…     

南美白对虾的营养需求

南美白对虾(Penaeus van-namei)原产于太平洋沿岸,该虾生长快、对饲料要求低、产肉率高、离水存活时间长、抗病力强,是迄今世界上养殖产量最高的虾种之一,它对于盐度的适应范围广,经驯化可在淡水中养殖,是海虾淡养很有前途的一个新品种。近年来,国外对南美白对虾的研     

暴雨过后鱼类疾病的防治

1 及时换水 暴雨过后,养殖鱼、虾、蟹和贝类的池塘应及时换水,通过几次换水逐渐将塘水pH值和盐度调节到鱼、虾、蟹和贝类正常的生理需要范围内。换水不能操之过急,第1次换水以排去表层水为好,不可1次将池水排出滩面（尤其是晴热的白天）。对于养殖南美白对虾的池塘,暴雨后不要一下子大量排去淡水、加进海水。应使池水逐渐咸化。关键是消毒海水,每天排去20～30cm塘水,再加满海水,逐步恢复到原来的海水养殖。     

南美白对虾营养需求研究进展

南美白对虾 (Ｐｅｎａｅｕｓｖａｎｎａｍｅｉ)原产于太平洋沿岸 ,生长快、对饲料要求低、产肉率高、离水存活时间长、抗病力强 ,是迄今世界养殖产量最高的虾种之一 ,它对盐度的适应范围广 ,经驯化可在淡水中养殖 ,是海虾淡养很有前途的一个新品种。本文综述其营养需求方面的研究进展 ,为我国南美白对虾养殖和饲料配制提供参考。1　蛋白质和氨基酸蛋白质是南美白对虾必不可少的营养物质 ,用来进行生长和组织修复。Ｃｏｌｖｉｎ和Ｂｒａｎｄ( 1 977)报道了南美白对虾的蛋白质需要量为 30 % ;Ｓｍｉｔｈ等 ( 1 985 )研究表明 ,南美白对虾的蛋…     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Mechanism of Action of Probiotic Function of Lactobacilli

乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.