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在日常的水产养殖生产实践中,除了鲢鳙鱼等滤食性鱼类可依靠摄食浮游生物和河塘中天然生长的水草及螺丝等天然饵料可利用外,在精养条件下均需进行人工饵料投喂,以弥补天然饵料的不足.一般来说投喂的饲料成本支出占养殖总成本的60%以上,占据各项成本支出的首要位置,故投喂饲料的种类不同与质量高低,直接关系到养殖者的经济效益,甚至是养殖的成败.根据饲料来源途径的不同,一般可以分为青绿饲料、农副产品料、食品下脚料、人工配合饲料及其它类等几个大类,上述种类的饲料运用于养殖各有利弊,通过分析,以期引起广大养殖者的关注,并有所裨益. 相似文献
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《饲料工业》2016,(10)
为探究三种投喂方式对小池塘鲤草鲫混养效果的影响,以肠道健康膨化饲料(蛋白水平30%、脂肪水平4%)为试验饲料,采用三种投喂方式:自动投喂(AF)、人工投喂(MF)和自助摄食(SF),在室外小池塘(10 m×10 m×1 m)条件下,研究不同投喂方式对鲤草鲫增重率、特定生长率、存活率、摄食率、蛋白质效率和饲料系数的影响。每种投喂方式设置3个重复,每个小池塘放养300尾鲤鱼、100尾草鱼、200尾鲫鱼,鲤鱼初始体重为(93.03±0.20)g、草鱼初始体重为(176.61±6.79)g、鲫鱼初始体重为(75.83±0.08)g,每天按照相同的投喂量(体重的2%~3%)投喂4次,试验周期为8周。试验结果显示:在鲤草鲫混养条件下,自动投喂组、人工投喂组和自助摄食组的鱼类存活率、蛋白质效率和饲料系数无显著差异(P0.05)。自助摄食组的鲤鱼和鲫鱼增重率、特定生长率明显高于人工投喂组和自动投喂组(P0.05),而草鱼的情况刚好相反(P0.05)。池塘鲤草鲫混养条件下,鲤鱼由93 g生长到318 g,草鱼由177 g生长到526 g,鲫鱼由76 g生长到155 g,肠道健康膨化饲料的饲料系数平均为1.37。试验表明:池塘中鲤草鲫混养时,三种投喂方式不影响鱼类的存活率、蛋白质效率和饲料系数,自助摄食方式利于鲤鱼和鲫鱼的摄食。根据本试验,建议在混养池塘中采用不需要电力又省力的自助摄食方式。 相似文献
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《养殖与饲料.饲料世界》2016,(8)
在洪湖和荆门的试验稻田中,进行"稻-虾"耦合养殖模式投喂人工配合饲料研究,洪湖试验点面积2 hm~2,平均产量1 980 kg/hm~2,饲料系数1.19,蛋白质效率50.25%,饲料报酬7.09;荆门试验点面积3.2 hm~2,平均产量1 920 kg/hm~2,饲料系数1.24,蛋白质效率52.17%,饲料报酬6.80。由此可见,基于"稻-虾"耦合养殖模式中投喂人工配合饲料,可提高克氏原螯虾的产量;人工配合饲料投喂报酬依稻田中天然饲料源的丰茂程度而定。 相似文献
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饲料是鱼类养殖中的主要成本,约占40%~60%。为降低饲料成本,使用美国俄亥俄州大学生产的复合蛋白粉代替虹鳟饲料中的鱼粉进行了试验。复合蛋白粉由羽毛粉、血粉、肉骨粉和家禽副产品组成。试验用虹鳟平均体质量1.93g,分别投喂含不同比例的复合蛋白粉的10种试验饲料,每种试验饲料设3个重复,与投喂鱼粉配合饲料的鱼作对照,投喂试验14周。鱼体生长结果表明,投喂含复合蛋白粉20%或40%饲料的虹鳟体质量与投喂鱼粉配合饲料鱼近似,用复合蛋白粉全部代替虹鳟配合饲料鱼粉,鱼生长下降。复合蛋白粉占饲料蛋白质的75%、鱼粉占25%的饲料喂养的虹鳟生长和… 相似文献
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王文彬 《养殖与饲料.饲料世界》2003,(7):31-31
南方大门鲇又称大口鲇,主要分布于长江流域的江河及通江湖泊之中。该鱼为凶猛肉食性鱼类,捕食各种鱼虾和水生昆虫,在人工驯养过程中,可使其食性由肉食性转变为摄食人工配合饲料,这为规模化、集约化人工养殖提供了广阔的前景。由于该鱼同类相残现象严重,故在其不同的养殖时期应讲求投喂技巧。 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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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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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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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