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省力化高效饲养是现代柞蚕产业的发展方向之一。秋柞蚕生产中常用的二移五龄窝茧放养法需要将5龄幼虫集中移入窝茧场,为减轻5龄期集中移蚕的劳动强度,研究建立了一种省工省力的放养新方法,即一移四龄窝茧放养法。通过对秋柞蚕不同龄期食叶量的测算,确定4龄期幼虫集中窝茧所需窝茧场的面积占全龄用柞园面积的70%~75%较为合理;测算2种放养方法窝茧期蚕体质量相差接近7倍,4龄期幼虫集中窝茧比5龄期幼虫集中窝茧节省移蚕用工量近40%。一移四龄窝茧放养法与二移五龄窝茧放养法比较,收蚁结茧率和单蛾产茧量均略有提高,说明采用这种新的放养方法对柞蚕生命力无不良影响。采用一移四龄窝茧方式放养秋柞蚕具有省工省力的优势,适用于秋蚕期柞园捕食性害虫发生量较小的年份。 相似文献
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为选育适合在一化性柞蚕产区放养的优质、高产、蛹丝兼用的柞蚕新品种,以四川蚕区的一化性柞蚕优良品种川06为亲本材料,采用系统分离育种方法,经25年25代系统选育,育成了优良柞蚕新品种川柞2号。川柞2号属一化性黄蚕血统,4眠5龄,全龄经过51 d,单蛾产卵量238粒,收蚁结茧率57.46%,千粒茧质量9.50 kg,千粒蛹质量8.31 kg,其全茧量比对照品种川06提高了13.58%。在农村多点生产鉴定试验中全茧量比对照品种川06和目前四川省主推品种川柞1号分别提高了7.13%和2.69%,千克卵产茧量比川06和川柞1号分别提高了8.73%和3.21%。川柞2号鲜蛹中的蛋白质质量分数为12.45%,粗脂肪质量分数为5.77%,氨基酸质量分数为9.72%,其中必需氨基酸质量分数为3.92%,且含有多种维生素。新品种川柞2号具有茧型大、产量高、抗逆性强、蚕蛹营养成分含量较高且氨基酸组成结构合理等特点,适合在四川、河南和湖北等一化性柞蚕产区推广。 相似文献
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柞蚕蛹暖茧期睾酮、雌二醇含量变化规律 总被引:1,自引:1,他引:0
70年代以后,对昆虫性激素研究再度兴起,在鳞翅目昆虫中主要以家蚕为研究对象[1~6]。柞蚕蛹中是否含有性激素,目前国内外还没有进行过报道,而研究其是否存在、变化规律,对养蚕业及医药工业都有重要价值。为此我们进行了相关的研究,报道如下。1材料和方法1.1试验材料试验所需的柞蚕茧由占林省蚕业研究所提供。品种青黄六号。雌雄各800粒,无病茧,保存温度为4℃。培育前一天,使茧蛹感受室温(8℃)一夜,第2天将茧蛹置于玻璃式恒温恒湿培养箱中培育,培育方法为标准暖茧法「”。经过培育:暖茧日期为24士0.sd见蛾,有效积温为235士5… 相似文献
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硫磺熏烟在蚕种生产上是防治僵病的有效措施之一,现在还被广泛应用。2005年秋季,我场蚕四组晚秋毛脚茧收回场后,在种茧保护中却出现了大批死蛹,导致781这一品种死蛹率达70%以上,个别户达100%,损失茧量1000多公斤,少制蚕种3000余张,造成了一定的损失。究其原因,认为与硫磺熏烟有关。针对这一问题,我场于2005年10月晚秋二批毛脚茧收回场后做了种茧保护期硫磺熏烟对蚕蛹影响的试验,探讨不同品种、不同熏烟时间和熏烟次数在同一环境下死蛹发生情况。为今后生产中提供可操作的依据。现将试验情况汇报如下:1试验材料原蚕茧来源于本场蚕五组晚秋原… 相似文献
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针对柞蚕绒茧蜂病的防治,进行了不同限制因子对防治药剂9901防治效果的影响试验。降雨对防治效果的影响:喷施0.25 mg/mL的9901可湿粉剂,3 h后降雨对防治效果没有影响,而喷药至降雨间隔1、2 h的防治效果分别为97.94%、97.73%,说明降雨对防治效果没有大的影响,确定喷药至降雨间隔1 h以上,不用二次补喷药剂。食药叶天数对防治效果的影响:用0.25 mg/mL的9901药液喷施柞叶,并保证柞蚕取食柞叶4 d以上,对柞蚕绒茧蜂病的防治效果可达95%以上,可以达到防治目的。 相似文献
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为验证柞蚕新品种 2 1 4在保种期内长途运输的安全性 ,开展了 1 5~ 2 0℃历时 8d的感温试验。结果表明 ,一化性柞蚕新品种 2 1 4的死蛹率、畸形蛾率都极显著地低于“二化一放”的柞蚕种茧 ,证实了一化性柞蚕种在保护过程中比二化性种茧有更强的耐变温能力。 相似文献
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柞蚕种茧是柞蚕生产的重要材料,种茧质量的优与劣可直接影响养蚕农户的经济效益,因此掌握好购种以及蚕种运输保护等技术措施,对提高养蚕农户的经济效益,推动柞蚕业的发展有着十分重要的现实意义.宁安市蚕业技术指导站在多年的购种工作中,按购种技术要求严把质量关,为养蚕农户购得优质种茧获得连续丰产丰收.我们在多年的购种实践中积累了经验,并总结归纳出选购柞蚕种茧以及种茧运输保护的技术要点. 相似文献
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文中利用变异系数、Shannon-Wiener多样性指数、相关性分析及聚类分析等方法,对50份二化性柞蚕种质资源的茧长、茧幅、茧形指数(茧长/茧幅)、千粒茧重、全茧量、茧层量及茧层率7个茧期性状进行统计分析。供试柞蚕种质资源间变异系数的变幅为1.36%~14.76%,茧层量的变异系数最大(14.76%),茧形指数的变异系数最小(1.36%);Shannon-Wiener多样性指数的变幅为1.94~2.06,全茧量指数最高(2.06),茧形指数最低(1.94),表明柞蚕种质资源茧期性状(除茧形指数外)具有较为丰富的遗传多样性,各性状间存在复杂的相互关系。基于7个茧期性状的聚类分析将50份柞蚕种质资源划分为3个类群,第Ⅰ类群包含18份种质,多为实用型种质;第Ⅱ类群包含13份种质,多为特殊遗传材料;第Ⅲ类群包含19份种质,多为多丝型种质。研究结果可为柞蚕种质资源的高效利用提供参考。 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