四川省农机系统投入抗洪救灾第一线

2007年7月2日以来,四川南充、达州、广安、巴中、泸州、遂宁等地遭受特大暴雨袭击,暴雨持续时间长、雨量大、来势猛、范围广,导致山洪暴发、山体滑坡,给这些地区的农业生产和人民生活造成严重损失。据不完全统计,此次暴雨洪灾冲毁提灌站     

秋季谨防鸡的肠毒综合征

<正>1临床症状发病初期,鸡群一般没有明显症状,精神正常,食欲正常,不出现伤亡。仅是个别鸡出现排稀薄、不成形,内含没有消化的饲料的粪便。此期持续时间较长,可达20～30天。随着     

大爱兴中华

2008年5月12日14时28分,四川汶川县发生8.0级地震,造成四川、甘肃、陕西、重庆、云南、山西、贵州、湖北8省市不同程度受灾.     

浅谈奶牛泌乳周期与情期的关系及提高繁殖率的对策

为了探究高产奶牛繁殖性能的变化,获取最大化收益,试验采用对泌乳牛每天24 h持续监测系统统计每头奶牛发情持续时间。结果表明:平均产奶量高于40 kg的奶牛发情持续时间(6.2±0.5)h短于低产奶牛(10.9±0.7)h(P0.01)。专家推荐所有泌乳天数达到75 d仍未配种奶牛有必要开始人工输精程序。如果定时配种程序从第75个泌乳天开始,则在第85个泌乳天进行配种。采用此种管理的牧场最大人工输精泌乳天数是85 d,牧场所有奶牛会在第85个泌乳天及之前得到首次人工授精。首次人工授精后33 d用促性腺激素释放激素(GnRH)对第一次输精的受胎率无影响。因此,可以改进定时配种程序,改进后奶牛两次人工授精间隔不超过42 d。     

Fungal inoculation induces agarwood in young Aquilaria malaccensis trees in the nursery

Fungi are often used to induce agarwood inAquilariatrees. This study was conducted to evaluate the effect of several fungi on agarwood formation over time in youngAquilaria malaccensis （Lam.） trees. Typical changes in the length and light intensity of the resulting discoloration were observed after three and six month periods following inoculation. Wood samples were observed microscopically and classified into several light intensity groups. The discoloration length was meas-ured longitudinally. The duration after inoculation affected the mean of discoloration length： the 6-month old sample （1.70 cm） had a wider discoloration zone when compared to the 3-month old sample （1.17 cm）. When measuring the discoloration intensity, a positive relationship with time was perceived. Digital images, captured using a camera-equipped microscope, revealed that wood samples collected after six months appeared to be 1.8-times darker than after three months. We concluded that time, not the species of any of the tested fungi, had significant effect on discoloration length and intensity. Gas chromatography/mass spec-trometry （GCMS） analysis of the 6-month old sample yielded some important agarwood compounds such as benzylacetone, anisylacetone, guaiene and palustrol. This demonstrates that the tested fungi have the ability to induce agarwood formation in nurseryA. malaccensis trees.     

Afforestation,restoration and regeneration——Not all trees are created equal

Undulations in weather patterns have caused climate shifts of increased frequency and duration around the world. The need for additional research and model data on this pressing problem has resulted in a plethora of research groups examining a particular tree species or biome for negative effects of climate change. This review aims to （1） collect and merge recent research data on regeneration within old- and new-growth forests, （2） highlight and expand upon selected topics for additional discussion, and （3） report how shade tolerance, drought toler- ance, and inherent plasticity affect tree growth and development. Al- though shade and drought tolerance have been well studied by a number of research groups, this review reveals that in-depth analysis of a single or a few species in a given area will not generate the data required to implement a successful regeneration plan. Studies using historical accounts of previous species composition, information regarding site sea- sonality, species competition, and individual responses to drought and shade are needed to （1） develop best management plans and （2） ensure future modeling experiments are focused on a greater variety of species using more innovative methods to evaluate climate change effects.     

两种较经济的自动投饲机时间控制电路

本文介绍的两种时间控制电路是为满足养鱼业中自动投饲的要求设计的。它可以控制投饲机的日投饲次数、每次投饲持续时间、投饲数量。电路除可实现自动控制，还可根据需要以手动来控制投饵机工作。     

为何“猪周期”难破

正该不该出台政策来调控猪周期,都调了那么多年了,如房价一般,效果比较有限。什么是真正的好调控政策,又该不该管?前几天看一篇学术论文,发现美国人过去也跟我们一样被忽高忽低的价格所困扰,他们的主要肉食品种是牛肉,也是经常出现牛周期,让美国难受数年。不过整体来看,美国的牛周期波动趋势是幅度愈来愈小,持续时间也愈来愈短。后来美国大规模的兼并重组,每个行业四大巨头所占份额70%甚至80%以上,牛周期少见了,但反寡头又出现了,这就导致消费者更难吃到便宜肉了。大型工业化养殖问题也不少,包括动物福利差,污染严重,农村空心化等。     

苹果发芽后至套袋前的管理要点

正2013年山东半岛雨量大且持续时间长。据招远水利局记载,4—8月基本上平均2d降1次雨,9月以后基本没有有效降雨。即前期光照时间短、土壤积水,造成果树大量死亡;未死的树因前涝后旱树体衰弱,成花少。加之今春气温回升快,开花早,属"早产儿"。据调查,大树减产43%,初果期树有增有减,平均略有增长。总体上产量呈下降趋势。从山东苹果主产区来看,秋后果品价格可能比较乐观。根据阜山镇的经验,在这种情     

影响猪繁殖配种的因素

1发情与排卵母猪的发情周期是母猪从上次发情开始到下次发情开始的时间,分为发情前期、发展中期、发情后期、休情期,一般16～25天,发情持续期为2～3天。母猪产后通常在3～6天之内发情,不排卵。排卵期是从发情开始后24～48小时,高峰时期为36小时,排卵持续时间为10～15小时,卵子到达输卵管腹部的时间为6～12小时,能保持8～10小时的生命活力。