体外培育赤眼蜂研究进展   总被引：2，自引：0，他引：2  

徐春婷  刘文惠等 《昆虫天敌》2001,23(3):132-144

体外培育赤眼蜂的国内外研究已达到相当平：随着人工饲料配方的优化，选用的人工卵壳材料更适合于赤眼蜂的寄生与发，以及人工卵卡机的研制成功和性能不断改进，产业化体外培育赤眼蜂已成为可能。体外培育赤眼蜂的品质管理问题是实现产业化体外培育赤眼蜂的关键。然而，国内外对体外培育赤眼蜂的品质管理研究涉及甚少，有待进一步研究。本文指出应开展体外培育赤眼蜂生物学特性、行为学特性和分子生物学特性的研究，并应用于品质管理，建立体外培育赤眼蜂的品质管理体系，促进实现体外培育赤眼蜂产业化的进程，从而满足农业生产上对赤眼蜂种群的大量需要。另外，人工卵滞育贮存法的突破有助于实现体外培育赤眼蜂的产业化，也应加强研究，最后，本文对体外培育赤眼蜂的应用前景进行了展望。  相似文献   

渭北旱塬畜牧业资源及生产配置问题研究     

李云毅  王雅鹏 《干旱区资源与环境》1993,(1)

畜以猪为主,肉以猪肉为主是渭北旱塬畜牧业资源及生产配置的基本格局,这种格局既不利于区位资源优势的充分发挥形成畜产优势,促进畜牧业发展;也不利于食物结构的改善和消费水平提高。为此本文从渭北畜牧业资源配置、生产配置现状问题出发,运用模糊数学、系统工程等原理,通过定性定量分析,提出了该区畜牧业资源及生产配置的战略思想。  相似文献   

Retrospective analysis of trends and production factors associated with sow mortality on swine-breeding farms in USA   总被引：2，自引：0，他引：2  

Koketsu Y 《Preventive veterinary medicine》2000,46(4):249-256

Of the 825 pig farms in USA that mailed in their electronic file containing production records, 604 farms were used to observe breeding-female mortality risk and related factors (herd size, lactation length, parity and season). Multiple regression was used to determine factors associated with annual mortality risk. Analyses of variance were used for comparisons of mortality risks among parity and season groups. Average annual mortality risks during the 1997 period was 5.68%. Average breeding-female inventories and average lactation length on USA farms were 733 and 18.3 days, respectively. Higher annual breeding-female mortality risk was associated with larger herd size, greater parity at farrowing and shorter lactation length (P<0.02). For example, as herd size increases by 500 females, mortality risk increases by 0.44%. Older parity was associated with higher mortality risks. Summer season was also associated with higher mortality risk. Using five-years’ records on 270 farms, annual mortality risk in 1997 was higher than those of 1993 and 1994, while average breeding-female inventory increased and lactation length decreased. It is recommended that producers, especially in large herds, pay more attention to breeding females.  相似文献   

Longevity of Swiss Brown cattle in different housing systems in Switzerland     

J.C. Bielfeldt  K.-H. Tlle  R. Badertscher  J. Krieter 《Livestock Science》2006,101(1-3):134-141

A Weibull mixed survival model was used to study the effect of a change in the housing system on length of productive life (LPL) in dairy cows. The data set included records on 71,469 Swiss Brown cows in 1674 farms in eastern and central Switzerland. About 36% of the records were right-censored. The observation period lasted from January 1, 1988 to May 1, 2001. During this period, 517 farms changed their housing conditions from a tie-stall barn to a loose housing system. Besides a random time-dependent effect of herd–year–season, the model included fixed effects of housing system, lactation number and stage of lactation, within herd and parity production level (all time-dependent), and age at first calving (time-independent). All effects had a significant effect on LPL at a level of p < 0.001. Cows in loose housing systems showed the lowest risk ratios of being culled (0.93) compared to the reference system tie-stall barn (1.00). The highest relative culling rate (1.09) was observed within the changing period from tie-stall barn to loose housing system. Within the first three lactations, the relative culling risk increased stepwise with lactation stage. The hazard slightly increased from first until lactation number 8 and higher. The relative culling rates were highest (2.22) for cows yielding less than 90% compared to herd-mates of the same lactation number, whereas the lowest risk ratios were estimated for animals yielding more than 110% compared to their reference group (0.64). When heifers were older than 3 years at first calving, there was a tendency towards a higher relative culling risk (1.06).  相似文献   

畜果结合生态养殖模式的研究     

赵芙蓉  王占彬  李保明  王朝元  梁臣 《家畜生态》2006,(4)

本研究系统探讨了果园和畜禽养殖的种养结合型生态模式,分析研究了“猪-沼-果”、“草-鸡-果”两种生态模式下的猪、鸡生产性能,畜舍空气质量以及苹果的产量和质量。研究结果表明:生态养殖模式下生长肥育猪和鸡的增重显著高于庭院养殖(P<0.05),分别提高了17.46%和29.28%;猪舍、鸡舍空气中的CO2和NH3比庭院猪舍、鸡舍显著降低(P<0.05);苹果产量比单纯果园平均分别提高28.97%和21.15%,含糖量分别相对提高6.79%和6.36%。  相似文献   

饲用莫能菌素的研究进展   总被引：2，自引：0，他引：2  

张晓庆  那日苏  周淑清 《中国牛业科学》2006,33(3):44-46

莫能菌素是聚醚类离子载体抗生素,是目前欧盟唯一允许使用的抗生素饲料添加剂。本文通过其作用机理、畜禽生产中的添加效果及使用剂量等方面的综合论述,证明了在畜禽生产中饲用莫能菌素的可行性,并为其今后的广泛应用做了研究展望。  相似文献   

奶牛生产寿命和产奶量的相关性研究     

李芬  周娟  马云  张立岗 《中国牛业科学》2006,32(6):12-14

本研究利用陕西省西安市现代农业开发区第二奶牛场1990年～2002年间249头已淘汰奶牛的胎次及产奶量记录等资料,对奶牛的生产寿命即第一胎次至淘汰的泌乳天数和生产效益的关系进行了研究。结果表明,奶牛的生产寿命与终生产奶量之间存在强正相关,相关系数为0．99。奶牛的使用年限和产奶量之间存在显著的曲线相关(P＜0．05)。此外,研究结果表明,该奶牛场奶牛不同胎次产奶量以第5胎次为最高。  相似文献   

Attachment and adhesion of conidia of Stagonospora nodorum to natural and artificial surfaces     

E. Zelinger  C.R. Hawes  S.J. Gurr  F.M. Dewey   《Physiological and Molecular Plant Pathology》2006,68(4-6):209-215

Attachment and adhesion of conidia of a wheat-isolate of Stagonospora nodorum to leaf and artificial surfaces was studied. Attachment of conidia was a non-viable process, separate from adhesion, that occurred rapidly and irreversibly. Attachment involved conidial-surface carbohydrates and was partially influenced by surface hydrophobicity. The subsequent adhesion, via the secretion of extracellular matrix from conidia, was a viable process that induced the complete cover of conidia in response to wheat leaf surface components containing epi-cuticular wax and to a lesser extent to barley but inducing only partial covering on glass. Results suggest that specific surface components from the compatible host promote rapid attachment and adhesion of S. nodorum conidia.  相似文献   

0.1%氯吡脲可溶性液剂对西瓜产量和品质的影响   总被引：2，自引：0，他引：2  

孙竹波  刘忠德  刘震  季敏  刘守柱 《北方园艺》2006,(1):25-26

0.1%氯吡脲可溶性液剂50 mg/kg、45 mg/kg、40 mg/kg(毫克/公斤)(有效含量)涂抹西瓜雌花果柄可显著提高西瓜座果率,从而提高西瓜产量,同时在一定程度上可增加西瓜的含糖量和维生素C的含量.  相似文献   

冷冻法测定梨的石细胞含量   总被引：12，自引：0，他引：12  

聂继云  李静  杨振锋  张红军  李明强 《果树学报》2006,23(1):133-135

以南果、安梨、砀山酥、秋白、锦丰、五九香、巴哈胜利、丰水、黄金、黄冠等10个梨品种果实为试材,对梨石细胞含量冷冻处理测定法的果肉切块大小、冷冻处理时间、匀浆时间、漂洗方法、平行性与准确度等进行了优化和系统研究,提出最适测定条件为果肉切块大小1.0cm3、-16～20℃冷冻处理24h、22000r/min匀浆3min。在此条件下,石细胞平均回收率为85.1%～94.1%,方法误差为4.65%～11.56%。研究结果为制定科学、实用的梨石细胞含量测定方法农业行业标准奠定了基础。  相似文献