共查询到19条相似文献，搜索用时 156 毫秒
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生长猪日粮中添加植酸酶的效果研究 总被引：4，自引：0，他引：4
用一个饲养试验和一个消化试验研究了１０００ｍｇ／ｋｇ植酸酶对生长猪生产性能和养分利用率的影响。饲养试验将１６头４５ｋｇ左右的长白ｘ荣昌Ｆ１杂交公猪随机分为２组，每组８个圈，每圈１头，分别喂给基础日粮、基础日粮＋１０００ｍｇ／ｋｇ植酸酶两种日粮。饲养试验开始后第２１ｄ采用全收粪法进行预试期７ｄ和正试期５ｄ的消化试验。结果表明：在４５ｋｇ左右生长猪日粮中添加１０００ｍｇ／ｋｇ植酸酶，日增重提高８．１５％（Ｐ＜０．０５），饲料效率改善４．１８％（Ｐ＜０．０５）；生长猪日粮添加植酸酶对干物质、粗蛋白质、粗脂肪、粗纤维的表现消化率分别提高１．１８％、２．７１％。５．０９％和１．５８％，统计上差异均不显著（Ｐ＞０．０５）。钙和磷的表观消化率分别提高１９．２２％和６８．００％，差异显著（Ｐ＜０．０５）。 相似文献
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为了解决冬季培育鲤鱼苗的饲料问题，从1981年冬开始，对鲤鱼苗的人工饲料进行了一系列的研究。1983年初研制成功“5号”人工开口饲料。用这种饲料直接喂养鲤鱼苗，可使其成活及正常生长。在鱼苗放养密度分别为20万尾／米。和10万尾，米^2，水中不合饵料生物的条件下，经过15天饲养，鱼苗体长分别可达到11—13毫米，体重可达15—22毫克，成活率为77—97％．5号饲料的成份为：粗蛋白36．7％，粗脂肪5．5％，粗纤维1．8％，水分8％，灰分19．0％，碳水化合物29％。 相似文献
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１９９２年莱州湾畔利用虾池暂养出池 海湾扇贝稚贝１１．１５亿粒，出商品苗２．４亿粒，保苗率为２１．５％，出苗规格３～５ｍｍ，比到外地购飞商品苗提前１５～天下海养殖。 相似文献
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鲤鱼配合饲料中鸡粪的最适添加量 总被引：2，自引：0，他引：2
在小网箱（有效养殖体积１ｍ＾３）中饲养杂交鲤（丰鲤，始重２２７ｇ／尾，投喂鸡粪含量分别为２０．２５和３０％的配合颗粒饲料，并以不含鸡粪（但加２５％玉米）的饲料作对照。喂养４２天，结果表明：添加２５％鸡粪的饲料，其饲养效果最佳。而未加鸡粪的对照饲料，其饲养效果最差。实验证明，鸡粪在鲤鱼配合饲料中的最适添加量为２５％；鸡粪作为鲤鱼的再生饲料优于玉米。 相似文献
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非离子态氨及亚硝酸盐对鳜鱼苗的急性毒性试验 总被引：11，自引：0，他引：11
通过毒性试验得出：２４小时、４８小时、９６小时非离子态氨对鳜鱼苗（９－１２ｍｍ）的半致死浓度和安全浓度分别为０．９２ｍｇ／ｌ、０．４９ｍｇ／ｌ、０．３２ｍｇ／ｌ、０．０３２ｍｇ／ｌ；亚硝酸盐对鳜鱼苗（１２－１９ｍｍ）的半致死浓度及安全浓度分别为７２４．４４ｍｇ／ｌ、１９０．５５ｍｇ／ｌ、７１．６１ｍｇ／ｌ、７．１６ｍｇ／ｌ。结果表明，水体中非离子态氨对鳜鱼苗的毒性作用较明显，而鳜鱼苗对亚硝酸盐有较强的耐受力。 相似文献
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鲈苗经中间培育和强化培育后，在养虾池改造成的土池中越冬３个多月，采取生物增氧等措施，越冬成活率达９６％以上。认为适宜池水深２．００￣２．６７ｍ，透明度应控制在４８￣６６ｃｍ，溶解氧保持在５ｍｇ／Ｌ以上。 相似文献
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This experiment, designed for the first time in the Middle East region to sustain Coregonus lavaretus production, examined the efficacy of a live organism ( Brachionus plicatilis ), an artificial diet (48% crude protein) and a mixed feed for the first 3 month of rearing fry. Nine rearing cages were floated on the surface of a natural pond supplied with hyporheic-zone river water, each containing 150 numbers of white fish fry, where they were treated with each of the three diets in triplicates. The fry were fed eight times daily starting at the onset of exogenous feeding. Results showed that fry utilized live organisms more efficiently than the artificial and mixed diets. Rotifer-fed group consistently showed higher growth rate during the entire experiment. Length increment (29.6 mm), weight gain (572.3 mg) after 12 weeks of feeding were higher ( P < 0.05) in this group. Also, their mean weekly specific growth rate (4.97% day−1 ) was the highest and feed conversion rate (2.97) was the lowest among all treatments. Survival rates of the fry declined from 75% to 61.4%, from 74.3 to 45.8% and from 72.7 to 54.5% for live feed, mixed diet and artificial diet, respectively. 相似文献
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The paper presents the results of rearing whitefish (Coregonus lavaretus L.) and peled (Coregonus peled Gmel.) in illuminated lake cages during a period of 4 years. In 3 successive years about 97 kg of summer coregonid fry were produced during initial 2-month rearing. Whitefish fry reached a length of 30.0–49.5 mm and an average individual weight of 201 mg–1 g. Peled fry reached 31.0–38.3 mm in length and 300–370 mg in weight. Whitefish survival rates amounted successively to 72.6% in 1977, 51.4% in 1978, and 3.1% in 1979. Survival rates for peled were 57.8%, 63.1% and 6%, respectively. Fishes at the age of 1+ and 2+ years showed high mortalities. Their growth rate was slower than in wild populations, and they did not attain sexual maturity. 相似文献
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双斑东方鲀全人工繁殖试验 总被引：2，自引：0，他引：2
对野生双斑东方鲀(Takifugu bimaculatus)人工繁殖的子一代进行人工培育,雌鱼须经三年性腺成熟,成熟系数为17.55%,雄鱼性腺成熟为两年。产卵前一个月,雌亲鱼经强化培育、催熟后,成熟系数可达到25.00%。对7组亲鱼注射LRH-A_2激素,共获鱼苗1.2048×10~6尾,其中全人工繁殖鱼苗9.592×10~5尾,对照组获鱼苗2.456×10~5尾。并就双斑东方鲀性成熟年龄等进行讨论。 相似文献
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不同浓度的枯草芽孢杆菌对罗非鱼鱼苗的养殖水体水质及其抗病力的影响 总被引：11，自引：0，他引：11
罗非鱼鱼苗的养殖水体中引入不同浓度的枯草芽孢杆菌,检测水体的水质指标、鱼苗体内与免疫相关酶的酶活力、鱼苗的生长率和成活率。实验结束时,引入1.0×10^4 cfu/mL枯草芽孢杆菌实验组,氨氮和亚硝酸盐氮含量分别为2.72 mg/L、0.15 mg/L,显著低于对照组（P〈0.05）;AKP活力、抗菌活力分别达249.9 U/g prot、0.59μg/mL,显著高于对照组（P〈0.05）;鱼苗成活率也显著高于对照组（P〈0.05）,比对照组提高了11.0%。结果显示：适合浓度的枯草芽孢杆菌能有效地改善鱼苗养殖水体的水质,提高机体免疫力和成活率。 相似文献
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A novel method for increasing fry yield in guppy breeding tanks was tested in the laboratory and commercial farms. It is based on lighting the fry collecting net baskets to attract newborn guppies into these safe refuges, which in turn reduces their exposure to cannibalism. A laboratory experiment revealed a significantly higher fry yield (by 30.2%) using illuminated net baskets than baskets without light. No significant effect of the timing of fry collection (08:00, 12:00 or 16:00) was found. Under commercial culture conditions in two farms, fry yields significantly increased by 13–28% in various guppy strains, using illuminated baskets. Overall, the results of this study demonstrated the efficacy and high economic potential of the proposed method in increasing fry yield in commercial-size breeding tanks. 相似文献