有关钢与钢筋混凝土组合梁设计问题的概述     

张增芳 《林业科技情报》2011,43(1):36-37

介绍了钢与钢筋混凝土组合梁的特点及设计内容,并简单归纳了组合梁中钢梁截面设计以及剪切连接件的作用和形式。  相似文献   

双壳贝类营养需求及人工饵料的研究进展   总被引：1，自引：0，他引：1  

杨创业  杜晓东  王庆恒  邓岳文 《动物营养学报》2016,(11):3422-3428

工厂化养殖是未来贝类产业可持续发展的必然趋势。由于微藻的培养容易受到气温、光照等自然环境条件的影响,而且占用大量水体,因此研发双壳贝类人工饵料已成为贝类工厂化养殖的关键因素。本文简述了蛋白质、脂类和碳水化合物对双壳贝类生长、繁殖及免疫的影响,详细叙述了微藻干粉、大型海藻处理物、酵母、微粒饲料、液态微胶囊饲料和固态微胶囊饲料6种人工饵料的研究进展,以期为研发新型的双壳贝类人工饵料及开展工厂化养殖提供依据。  相似文献   

Specific polyphenol oxidase activity of red clover (Trifolium pratense) and its relation with forage quality in field experiments     

Birgit Eickler  Jana Kleen  F. Taube 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(1):39-49

Abstract

In feeding studies, red clover (RC) influenced positively the N utilization by ruminants. A relationship between polyphenol oxidase (PPO) activity and forage quality has not been established. Our objective was to investigate seasonal, site, genotype, and management effects on specific PPO activity in RC in three experiments under field conditions, and relate the activity to forage-quality parameters. In Experiment 1, six RC genotypes at two study sites were submitted to a 3-cut system. Specific PPO activity, forage quality, and vegetation stage were determined. PPO activity varied between harvest and study sites, with genotypes differing up to 3-fold in PPO activity within harvests. The specific PPO activity, forage quality, and vegetation stage in RC subjected to 5-cut system and grazing (Experiment 2) were determined. Additionally, in Experiment 3, cutting frequency in RC swards including mechanical stress (rolling) was investigated. The induction of PPO activity in RC by grazing or mechanical stress (Experiments 2 and 3) increased the activity up to 2.5-fold compared with RC at similar vegetation stage submitted to the 5-cut system. Mechanical stress induced by grazing or rolling, and seasonal differences, seem to have a larger influence on specific PPO activity than does the genotype effect observed in Experiment 1. For forage quality, an increased specific PPO activity explained 29–46% of the reduction in protein fraction ‘A’ content (non-protein N) in the cutting systems in Experiments 2 and 3. Other CP fractions achieved a lower relation. Furthermore, the precipitation-to-temperature ratio preceeding a harvest explained 63% of the variation in the specific PPO activity. In conclusion, the PPO activity in RC is induced by grazing and rolling. Whereas weather conditions preceeding a harvest showed a large influence, genotype influence had only minor relevance. These results may have implications for regional harvest management towards efficient N utilization by ruminants.  相似文献   

The phytase analytical activity of pelleted diets may not adequately describe efficacy in the bird     

《The Journal of Applied Poultry Research》2012,21(3):492-501

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Variations in preenrichment pH of poultry feed and feed ingredients after incubation periods up to 48 hours     

《The Journal of Applied Poultry Research》2013,22(2):190-195

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甜高梁秸秆酒糟复合饲料的初步研制   总被引：1，自引：0，他引：1  

边文祥  田瑞华  段开红  付妍  赵红军 《畜牧与饲料科学》2010,31(1):37-38

以甜高粱秸秆发酵乙醇后的酒糟作为原料,与其他饲料进行简单复配,制成了适口性好、价格低廉、具有一定饲用价值的粗饲料。其配制方法简单且易于推广,既补充了动物养殖的粗饲料,又提高了甜高粱秸秆的综合利用率,还可减小发酵企业对环境的污染。  相似文献   

瘤胃微生物对饲料中霉菌毒素的脱毒作用     

龙淼  李鹏  张燚  朱连勤  刘国文  王哲 《中国饲料》2012,(1):37-39,43

反刍动物瘤胃内微生物数量巨大、种类繁多,具有多种生理功能,对霉菌毒素也具有高效的脱毒作用。本文介绍了近年来瘤胃微生物对几种主要的霉菌毒素的脱毒作用。  相似文献   

不同饲料饲喂断奶仔猪对比试验研究     

郭雪洁  陈辉  王立强 《畜牧兽医杂志》2012,31(2):18-20,23

为了给断奶仔猪选择合适的饲料类型,采用2种类型的饲料对60头35日龄断奶的仔猪进行饲养试验。试验分为2组,即颗粒饲料组和粉状饲料组,每组三个重复,经30 d的饲养试验,结果表明：颗粒饲料组仔猪体质量每日增加数、日头均耗料量明显高于粉状饲料组（P〈0.05）,且颗粒饲料组的经济效益要高于粉状饲料组,而饲料转化效率没有明显差异（P〉0.05）,说明颗粒饲料比粉状饲料更适合饲喂断奶仔猪.  相似文献   

酸化剂在畜牧业上的应用研究进展     

张宜辉  宗卫阳 《饲料与畜牧》2013,(4):18-20

酸化剂作为提高饲料酸度，提高饲料消化利用率的添加剂，在饲料工业上应用日益广泛。文章从酸化剂的发展历史、分类、作用机理、应用及发展前景方面进行了综述。  相似文献   

蛋鸡饲料配方的研究与设计     

娜日娜  韩晓华  索力墨  乌仁图雅 《饲料与畜牧》2013,(10):13-15

蛋鸡饲料配方的设计是一门严谨的科学，既关系到养殖安全和产出效益，又要兼顾高成本投入下的利润，I还要适应市场需求，有市场竞争力。  相似文献