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海虾淡养是指将海水虾类经淡化后放入淡水中进行养殖的一种方法。由于近年来虾病的 广泛流行,使海水养虾业受到严重影响。为了摸索新的养殖模式和方法,不少省市进行了淡 水养殖刀额新对虾和南美白对虾的新尝试,并获得了成功,为发展海水虾的养殖找到一条新 的途径。我市近两年来也进行了刀额新对虾和南美白对虾淡水养殖试验和刀额新对虾人工育 苗试验,获得可喜效果,并初步总结出养殖技术要点。 1 品种介绍 1.1 刀额新对虾 刀额新对虾(Metapenaeus ensis)俗称基围虾,亦称砂虾、泥虾、 土虾等,属对虾科、新对虾属,分布于我国南方的广东、福建沿海,其壳薄体肥,肉嫩味美 ,且生命力强,常能以活虾面市,深受国内外市场的欢迎,是我国近海重要的经济虾类之一 。 刀额新对虾体色土黄到棕褐色,额角上缘6~9齿,下缘无齿,无中央沟,第一触角上 鞭约为头胸甲长的1/2。刀额新对虾属中型虾 相似文献
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刀额新对虾是一种适宜于海、淡水养殖的对虾新品种,身体肥壮而结实,肉质脆嫩而鲜美,对水中低溶氧的忍受程度和离水后的耐干能力及存活时间均比其他虾类强,且活体运输方便。刀额新对虾的个体虽比长毛对虾小些,但肉质胜过其他对虾,深受消费者青睐,是一种创汇的水产新品。 相似文献
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对虾饵料中氨基酸的含量与比例对中国对虾生长的影响 总被引:3,自引:1,他引:2
本试验采用了五种饵料配方养殖中国对虾,结果是以虾体氨基酸含量与比例为标准配合的对虾饵料(配方1和配方4)和与蛤仔氨基酸含量与比例为标准配合的对虾饵料(配方2)相比,差异显著(P<0.05),与市场出售的饵料(对照1)相比差异极显著(P<0.01)。添加人工合成的蛋氨酸求得对虾饵料氨基酸平衡,并用PVA-缩醛包裹(配方4),可明显提高养殖效果,与氨基酸的含量及比例虽然相同,但不用PVA-缩醛包裹的配方3和配方5相比,差异显著(P<0.05)。与饲喂鲜活的蛤仔(对照2)相比,差异不显著(P>0.05)。与配方1相比,差异不显著(P>0.05),但配方4因添加人工合成氨基酸而减少动物性蛋白的用量,降低了成本,经济效益高。 相似文献
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1998年在疫区内某对虾养殖场,用对虾副粘病毒细胞培养灭活疫苗,对日本和中国对虾苗(体长0.8~1cm)进行了侵泡免疫试验。对虾养殖试验结果表明,5月3日放苗后,免疫试验组对虾没有发病,其中单纯用疫苗免疫的日本对虾试验池的对虾规格,养殖73d(至7月15日)平均达95尾/kg,219d(至11月8日)平均达38尾/kg,2次出池合计平均170.9kg/km^2;单纯用疫苗免疫的中国对虾试验池的对虾规格,养殖86d(至7月28日)平均达110尾/kg,221d(至11月10日)平均达22尾/kg,2次出台合计平均167.3kg/hm^2。日本对虾和中国对虾的免疫试验对照池与非免疫试验池的对虾,分别于6月28日和7月15日发生副粘病毒病而死亡。 相似文献
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深圳市某虾场养殖的斑节对虾(Penaeus monodon)出现异常死亡,经组织病理学剖检和电镜观察,证实了引起对虾死亡的原因为肝胰腺细小病毒(Hepatopancreatic Parvovirus,HPV)感染。 相似文献
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我国养殖对虾的品种有:中国对虾(Penaeuschinensis)、长毛对虾(P.Penicillatus)、斑节对虾(P.monodon)、日本对虾(P.japonicus)、墨吉对虾(P.merguiensis)和刀额新对虾(Metapenaeusensis)等6种,其中以中国对虾为主,对营养需求和饵料配制技术研究的主要对象也是中国对虾。我国对虾养殖自70年代末起步,至1991年产量近21万吨,居世界第一位,之所以有如此迅猛的发展,在技术上主要是靠工厂化育苗和配合饵料。而配合饵料的研制成功,质量不断提高,是基于对虾营养的基础研究和加工技术的进步。中国对虾营养需求及营养生理研… 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
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。 相似文献
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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。 相似文献
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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. 相似文献
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以国际标准强毒R株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离MG,并收集感染鸡所产蛋分离MG。结果表明,人工感染48小时后上、下呼吸道及肺已被全面感染,96小时气囊已被感染,120小时输卵管已能分离到MG,卵巢始终分离不到MG。人工感染鸡自144小时便能在其所产蛋中分离出MG。药物治疗能在72小时内消除感染,油乳剂苗则需24天后逐渐降低蛋内MG分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内MG,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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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. 相似文献