Reproductive Performance of Crossbred Dairy Cows in Different Production Systems in the Central Highlands of Ethiopia

The study was conducted to examine the fertility status of crossbred dairy cows in mixed crop-livestock production (MCLP), market-oriented specialized dairy production (MSDP) and urban dairy production (UDP) systems, including the Holetta Agricultural Research Center (HARC). Data on general farm management variables and reproductive histories were collected from study farms by questionnaire and from individual cow records. Age at first service and age at first calving were 29.58 months (n = 424) and 40.6 months (n = 348), respectively. Cows managed under UDP were younger at first service and at first calving (p<0.05). The mean intervals from calving to first service and to conception were 141.98 days (n = 284) and 185.02 days (n = 219), respectively. The mean calving interval for cows was 551.82 days (n = 258). Cows in MCLP had longer intervals from calving to first service and to conception and longer calving intervals than those managed under MSDP, UDP and HARC. First service conception rate (43.42%), number of services per conception (1.75) and pregnancy rate (79.29%) did not differ significantly between production systems. Reproductive performance was best in UDP followed by HARC and MSDP. The difference between MCLP and the rest points to particular difficulties in that system. To improve reproductive performance and economic benefit, there should be conservative stocking rate, sensible year-round feeding, a herd health plan, and sustainable extension service.     

Do labour productivity and preferences about work load distribution affect reproduction management and performance in pig farms

Increases in labour productivity are essential factors, as well as technical effectiveness, for the competitiveness of pig farming. However, the preferences of farmers for controlled (i.e. limited) daily working hours or available days for vacation also increase. The objective of this study was to explore how these preferences about work might be associated to specific combinations of practices or affect performance. The study was carried out by direct investigation of the stockbreeders. Data analysis used factorial analysis to identify relationships between practices, labour productivity, sow productivity and work load distribution. Results showed independence between sow productivity and labour productivity. Three independent types of preferences about work load distribution were identified: the limitation of density of daily work, the avoidance of insemination activities during the weekend and the avoidance of farrowing supervision during the weekend. These preferences about work load distribution were mainly related to weaning, oestrus detection and insemination techniques. A relationship was also seen between farrowing and cross-fostering techniques, and labour and sow productivity. Results suggest that preferences about work load distribution influence the choice of reproduction practices without influencing performance. Finally, concerning the labour productivity, it was linked with some specific techniques at farrowing but the results also indicated that it was mainly related to the size of farrowing batches.     

微机地理信息系统软件PC ARC／INFO功能简介

本文主要介绍了微机地理信息系统软件 PC ARC/INFO 的结构,主模块 ARC 及其主要子模块的功能,系统优化的方法及该系统当前的主要应用领域及前景展望。     

健全质量管理体系 保证蚕种检验检疫质量

阐述了浙江省蚕种质量检验检疫站质量管理体系的构建与运行实效,对确保全省蚕种质量的作用。     

A novel treatment for dynamic laryngeal collapse associated with poll flexion: the modified checkrein

Reasons for performing the study: Dynamic laryngeal collapse (DLC) associated with poll flexion is a performance limiting dynamic upper airway disorder commonly diagnosed in Coldblooded trotters. An inspiratory obstruction occurs when affected horses are driven with tension on the reins, inducing poll flexion. To date, surgical treatment and conservative management have failed to improve racing performance in affected horses. Objectives: To test the efficacy of an external device, the modified checkrein, in limiting poll flexion, diminishing laryngeal collapse and improving airway mechanics when horses are driven on a treadmill with tension on the reins and test the hypothesis that the modified checkrein will limit poll flexion thereby improving endoscopic appearance of the larynx and reduce airway obstruction in harness racehorses affected with DLC. Methods: Fourteen Norwegian Coldblooded trotter (NCT) racehorses previously diagnosed with DLC associated with poll flexion exercised on a high‐speed treadmill at speeds that resulted in heart rate >200 beats/min. Upper airway videoendoscopy recordings, tracheal pressures and video recordings of the head and neck position were collected while horses exercised with the conventional checkrein on Day 1 and the modified checkrein on Day 2. Results: The modified checkrein successfully limited poll flexion as measured by no change in head position parameters between phases of no rein tension and phases of rein tension. Endoscopic scores were significantly improved (arytenoids cartilage collapse P<0.0001; vocal fold collapse P<0.0001) and tracheal peak inspiratory pressures were significantly less negative (P = 0.0162) when horses were fitted with the modified checkrein compared to the conventional checkrein. Conclusions and potential relevance: The modified checkrein successfully limited poll flexion and also prevented upper airway obstruction in NCT horses affected with DLC associated with poll flexion. The modified checkrein seems promising in offering a method of conservative management in harness racehorses affected with this disorder.     

论野火的三属性

野火泛指发生于野外植被中的火、归纳发现有３个基本属性,自然性,灾害性和工具性,对这３个属性进行明确的定义和认识,有助于理解野火的意义,为研究和生产奠定科学系统的理论基础。自然属性一是指其自然存在、二是指其对自然界有影响,三是指其他受其他自然因子制约。灾是自然界不可控事件造成的超越一定程度界线的损失。灾害属性即经济属性。每一次火都造成巨大的经济损失,包括林资源和草资源预防和扑救开始。工具是指可以拿来     

蜜蜂秋季管理要点

科学合理的蜜蜂秋季管理,不仅可以使蜜蜂安全越冬,还能促使蜜蜂来年早春的春繁顺利进行。为了向广大蜂业工作者提供一个全面的蜜蜂秋季管理参考资料,从蜂箱、蜂群、饲喂及病害防治4个方面入手,对蜜蜂的秋季管理要点进行整合。     

论农民工的媒介素养教育

农民工是中国经济建设的主力军,他们是连接城乡二元社会的纽带,然而他们又是被社会忽略的群体,常常徘徊在媒体之外。在信息社会,掌握充分的信息资源意味着竞争力和财富,农民工作为中国经济的建设者应该全面提升自己的媒介素养从而提升自己的话语权,改变自己的社会地位。文中对农民工的媒介素养作了分析,并提出了加强农民工媒介素养教育的途径。     

千年菊在西宁地区的容器育苗及栽培管理技术的初步研究

以千年菊为试验材料,利用沙子、有机肥、园土为原料,配制成人工育苗栽培的3种不同基质,进行反季节的花卉生产培育。通过利用不同基质培育千年菊苗,对千年菊的株高、茎粗细、开花的早晚、开花期长短进行研究,试验发现:千年菊在人工栽培条件下生长速度快,在西宁地区出苗率、移栽率、成活率较高且花期较长。千年菊生长在园土+有机肥+沙子(1∶1∶1)中较为理想。