水分子乳化剂及加水方式对饲料水分活度的影响

<正>饲料霉变是饲料加工及贮存最常面临的现象,是影响饲料质量的一个重要因素。水分含量是霉菌等微生物在饲料上生长繁殖和各种生化反应的重要因素之一。饲料中的水分有结合水、体相水和吸润水三种存在形态。其中结合水包括结构水、单分子层水以及多分子层水,结构水被非水物质整体部     

水质管理及饮水系统清洗

1水质对家禽营养的影响1．1水是最关键的营养物质家禽的摄水量几乎是采食量的2倍，水在家禽代谢中的作用举足轻重。水有调节家禽体温、促进食物消化和废物的排泄作用，是家禽有效生产的最基本因素之一。     

水质改良剂对犊牛饮水量及饮水质量的影响

本试验旨在了解规模化奶牛场犊牛饮水量,分析水质改良剂对犊牛饮水量和饮水质量的影响。试验选取24头犊牛分为3组,即对照组、碘制剂组、泡腾片组,测定各组犊牛日饮水量,并在更换饮水后0h、2h、4h、6h采集犊牛饮水桶中水样,测定大肠杆菌最大可能数,并分析24头40日龄犊牛3次饲喂期间饮水量的变化情况。结果表明:犊牛40日龄日平均饮水量为4.411±1.855L,犊牛饮水中添加碘制剂和泡腾片不影响犊牛饮水量,对照组饮水2h后大肠杆菌最大可能数达到76448MPN/100mL,超出无公害食品畜禽饮用水水质(NY5027-2008)规定犊牛饮水中大肠菌群数(<10MPN/100mL)的760倍,而添加水质改良剂的犊牛饮水中4h内未检出大肠杆菌,表明犊牛饲养管理中的犊牛用一个器具饲喂牛奶和饮水的方式需要引起关注,可通过饮水改良剂进行饮水质量控制。     

Fall Water Effects on Growing Season Soil Water Content and Plant Productivity

Understanding fall precipitation effects on rangelands could improve forage production forecasting and inform predictions of potential climate change effects. We used a rainout shelter and water addition to test effects of seasonal precipitation on soil water and annual net primary production of C₃ perennial grass, C₄ perennial grass, annual grasses, forbs, and all plants combined. Treatments were 1) drought during September−October and April−May (DD); 2) drought plus irrigation during September−October and drought during April−May (WD); 3) year-long ambient conditions (WW); and 4) ambient plus irrigation during September−October (W + W). Treatments created conditions ranking among the driest and wettest September−October periods since 1937. Fall water effects on soil water were not detectable by May at 15 cm and 30 cm. Effects persisted into July at 60 cm and 90 cm, depths below the primary root zone. With spring drought, annual net primary production was 344 kg ha⁻¹ greater when the previous fall was wet rather than dry. No differences were detected between fall water treatments when spring was wet and fall was about 184% (1 938 ± 117 kg ha⁻¹) or 391% of the median (1 903 ± 117 kg ha⁻¹). Fall water increased C₃ perennial grass when spring was also wet and had no effect under spring drought, when forage production concerns are greatest. Fall water did not affect C₄ perennial grass, and extremely wet fall conditions reduced forb production about 50%. The greatest effect of fall water was increased annual grass production. Even record high levels of fall water had minor effects on biomass, functional group composition, and soil water that were short-lived and overwhelmed by the influence of spring precipitation. Movement of fall water to deep soil by the growing season suggests plants that would most benefit from fall precipitation are those that could use it during fall (winter annuals), or deep-rooted species (shrubs).     

黄墟镇禽用浅井水质调查

普查镇江市黄墟镇104口浅井水质,并长期监测了其中7口的水质。结果表明：pH值超标率为11．5％,总硬度仅有1口超标,且氯化物含量较低,属中性软水和低度碱性硬水区域;氨氮超标率70．4％,为主要面源污染物;监测的七口井氨氮浓度在七、八月份和十一、十二月份比较高,COD随着时间的推移呈现增加趋势,氯化物含量很低,且与总硬度呈线性关系,凸现种植业污染特征。     

黄墟镇禽用浅井水质调查

普查镇江市黄墟镇104口浅井水质,并长期监测了其中7口的水质。结果表明：pH值超标率为11．5％,总硬度仅有1口超标,且氯化物含量较低,属中性软水和低度碱性硬水区域;氨氮超标率70．4％,为主要面源污染物;监测的七口井氨氮浓度在七、八月份和十一、十二月份比较高,COD随着时间的推移呈现增加趋势,氯化物含量很低,且与总硬度呈线性关系,凸现种植业污染特征。     

水体富营养化研究进展

本文主要阐述水体富营养化形成的机理和原因,以及水体富营养化的危害。提出当前防治和治理水体富营养化所采取的主要措施。     

Daily Occurrence of African Game Animals at Water Water Holes During Dry Weather

In West Africa, the lion is currently characterised by small populations that are fragmented and often isolated from one another, with virtually no ecological connection. In addition, lion populations are generally declining. In recent reports, in Ghana the lion has been declared functionally extinct, if not completely eradicated, and recent surveys have made conclusions as to the probable extinction of lions in Mole National Park (MNP) in Ghana’s Northern Territory. The aim of this report is to highlight the lion’s continued presence in MNP, an area that must continue to be considered for species conservation, and therefore studied carefully. In April 2011, a young male lion was filmed using camera traps, and a roar was clearly audible. The choice of where to place the camera traps (n = 20) was based on a habitat suitability model developed using lion records collected over 41 years. Additional records support our data, which demonstrate that MNP could possibly still be considered as an area designated for lion conservation in West Africa, even considering the significant findings based on molecular biology that prove that lions in West and Central Africa are clearly differentiated from other African lions.     

灌溉量对紫花苜蓿水分利用效率和耗水系数的影响

采用大型非称重式蒸渗仪法,在河北省坝上地区研究灌溉量对紫花苜蓿(Medicago sativa L.)水分利用效率和耗水系数的影响。结果表明:随着灌溉量由0增至400 mm,紫花苜蓿耗水量由335.5增至712.8 mm,干物质产量由3304.7增至7423.3 kg/hm²,二者差异显著(P<0.05);第1茬生物产量和经济产量水分利用效率分别由10.5和12.2降至6.8和7.9 kg/(mm·hm²),第2茬则相反,分别由9.5和11.1增至19.0和22.1 kg/(mm·hm²),但第1~2茬差异不显著;第1茬耗水系数分别由956和822升至1480和1273,第2茬则相反,分别由1053和906降至527和453,但1~2茬差异不显著;不同茬次间水分利用效率及耗水系数差异显著(P<0.05)。     

灌溉量对紫花苜蓿水分利用效率和耗水系数的影响

采用大型非称重式蒸渗仪法,在河北省坝上地区研究了灌溉量对紫花苜蓿（Medicago sativa L．）水分利用效率和耗水系数的影响。结果表明：随着灌溉量的增加,第1、2、3莅和全生长季（1～3茬）生物产量和经济产量水分利用效率皆呈现先升后降的趋势;第1茬中灌溉量处理显著高于低和高灌溉量处理（P〈O．05）。随灌溉量增加,各茬次和全生长季（1—3茬）生物产量和经济产量耗水系数均呈先降后升趋势;第1茬中灌溉量处理显著低于低和高灌溉量处理（P〈0．05）。不同茬次间水分利用效率及耗水系数差异显著（P〈0．05     

牧草中的水溶性碳水化合物

牧草中有适量的水溶性碳水化合物对家畜及牧草都有十分重要的意义。本文从牧草中水溶性碳水化合物的种类、影响因素、贮存过程中的损失和对家畜的营养价值等方面加以综述。     

浅谈水利高校节水循环系统

我国水资源贫乏,时空分布不均,与我国经济发展、民生需求的矛盾日益突出。考虑现今与未来的发展,树立节水意识、提高水资源的利用率迫在眉睫。而水利高校节水循环系统的建立能适当地缓解这个重大问题,并且成本较低,具有一定的长远效应。     

牧草中的水溶性碳水化合物

牧草中有适量的水溶性碳水化合物对家畜及牧草都有十分重要的意义.本文从牧草中水溶性碳水化合物的种类、影响因素、贮存过程中的损失和对家畜的营养价值等方面加以综述.