冷藏浸酸种养活生种的新方法

将生种率市的蚕种在两２胚胎期于５℃再冷藏２０－２２天可以减少生种的发生。     

普通种场控制生种发生浅谈

在笔者从事十多年的蚕种生产过程中,从1990年起开始接触生种。目前的当家品种“9·芙×7·湘”,中系品种的原原种“932”和“芙蓉”均带多化性血统。若受外界环境不良影响,极易产生生种。生种的发生,不但影响蚕种的外观质量,打乱企业     

我国的猪种资源

<正> 关于我国猪种资源的情况,早在公元三世纪时,即已有了较完整而全面的报道,如《博物志》中载有区划全国猪种类型的记述:“猪,天下畜之而各有不同:生青、兖、徐、淮者耳大;生燕、冀者皮厚;生梁、雍者足短;生辽东者头白;生豫州者咮短;生江南者耳小,谓之‘江猪’;生岭南者白而极肥”。这一记述,生动地描绘了我国各地丰富多采的猪种资源情况及其全面区划的实     

浅谈减少生种发生率的体会

前几年,我所生产的“两广二号”普通种的正交种生种较多,尤以遂溪前进农场的原蚕点最为严重,特别是在2000年秋制的第一批种,生种率高达30%,甚至出现整张蚕种都是生种的情况。生种既严重影响蚕种质量,又造成了生产上的损失,导致经济效益下降,蚕种场为此大伤脑筋。我所近两年来通     

松嫩平原优势种羊草与其主要伴生种芦苇空间分布格局分析

芦苇是松嫩草地优势种羊草的主要伴生种,两者常常形成物种组成比较单一的混生群落或者与其他物种组成羊草 杂类草群落.选择羊草 芦苇混生群落,羊草群落和芦苇群落的交错区进行羊草、芦苇单物种格局分析.结果表明,1)混生群落和交错区中,羊草和芦苇均是以集聚分布的形式存在;2)羊草在混生群落中的格局强度小于交错区中的格局强度,芦苇在2种类型群落中的格局强度没有显著差异;3)除了考虑物种的生物学特性以外,混生群落种内、种间竞争也是影响羊草集聚分布和格局强度的主要因素,交错区中,环境异质性和种间竞争是影响集聚分布和格局强度的重要因子;4)芦苇在混生群落和交错区中格局强度没有明显差异,由此可以判定芦苇的空间分布格局形成主要受植物本身生物学特性的影响.     

春期杭7生种发生原因分析

1987年春我场饲养杭7 450克,发生生种蚁蚕10.5公斤,平均每饲养1克蚁量,发生生种22.33克,估计损失净种1000盒,产值7000元。杭7是一个较易发生生种的品种,近年来我场每年都有不同程度的生种发生。1980年饲养730克,每克蚁量发生生种蚁量11.9克,1982年饲养780克,每克蚁量生种蚁量     

高温与生种发生的关系

蚕种场,是生产越年性优良蚕种的,可是,近年来,好多蚕种场,蚕种制好后,发生的生种颇多,尤其是杭7杭8二品种,生种发生率更高,有的场仅因生种问题,竞严重地影响了生产计划的完成.为此,在蚕种生产上,如何控制生种问题,实是当务之急.     

浅析温差与生种的发生和控制

家蚕二化性品种产生生种和黑种是体内基因控制和环境影响共同作用的结果,研究含多化性血统的二化性家蚕品种生种的产生与外界环境之间关系对家蚕良种繁育具有重要现实指导意义。本文将从多年来从事蚕种生产中总结的生种发生规律入手分析生种发生与外界环境关系。认为温差变化是影响生种发生的重要因素;一般     

给桑量与生种的关系

杭7、杭8一代杂交种,是浙江春用的当家品种,在秋蚕饲养中成绩亦较好,但生种发生甚多,有的场,竞因发生生种而完不成生产任务.又春繁的皓月,菁松和秋用的苏12,浙农1号,亦有生种发生,给蚕种生产带来损失.如何控制生种的发生,实是当务之急.为探索生种发生的环境固子,1982年一     

浅谈今秋生种发生的原因及防止措施

今秋,我公司生产的菁松×皓月普通杂交种生种较多,尤以1~5批最为严重,特别是A段制种,生种率高达50%,甚至出现整张蚕种布上的蚕种都是生种的情况,另外,该品种的其他批次也不同程度地出现生种。生种既严重影响蚕种质量,又造成生产上的损失,导致经济效益下降。我们通过对今秋原蚕饲育过程中出现的一些情况和问题进行总结、分析,浅谈几点看法(主要是影响生种发生的外界条件)。1原蚕在生长发育过程中受到不良外界环境因素的影响,诱发生种影响生种发生的外界条件主要是温度、光线和饲料等。1.1桑叶的质量对生种形成的影响蚕的营养完全来源于桑叶,…     

IgY在免疫检测及治疗中的应用进展

卵黄抗体(IgY)是存在于卵黄中的免疫球蛋白,是鸟类、爬行动物和两栖类动物体内的主要抗体,具有强大的免疫功能。论文介绍了卵黄抗体的分子结构和理化特性,综述了IgY在寄生虫(弓形虫、血吸虫、球虫)、细菌(肠产毒素大肠埃希菌)、病毒(B型流感病毒、狂犬病病毒)等病原检测、抗生素(卡那霉素、庆大霉素)残留检测及相关疾病如雏鸡球虫病、猪大肠杆菌病、鳗鱼弧菌和利斯顿氏菌病、轮状病毒病治疗中的应用,并指出目前IgY应用中存在的诸如可能存在禽类未知病原、尚无生产标准规程以及稳定性不够理想等问题。因卵黄抗体具有安全、高效、无公害的特点,其在疫病检测和防治中具有广阔的应用前景。     

卵黄抗体在病毒性疾病防治中的应用

病毒性传染病一直以来对动物与人的危害极大,而常见抗病毒药物对细胞有较大毒性,且病毒容易发生变异,因此给抗病毒药物的研制增加了难度。卵黄抗体因其获取方便、获得量大、生产工艺相对简单、可进行规模化生产、性质稳定,因此广泛应用于动物与人的病毒性疫病防治中。论文阐述了卵黄抗体的产生、结构、优势、作用机理等内容,并对卵黄抗体在动物与人病毒性疾病防治中的应用和已商品化的产品现状进行了综述,汇总研究之不足,若卵黄抗体能得到更深入的研究,克服不足,在今后的应用过程中将具有更加广阔的前景。     

鹅蛋与鸭蛋生物学特性的比较

作者旨在研究地方品种鹅蛋与鸭蛋的生物学特性差异。同期采集固始白鹅种蛋56枚,淮南麻鸭种蛋64枚,对外部特征和内部品质进行对比。结果表明二者之间存在较大差异,鹅蛋与鸭蛋各指标分别为：蛋重（159.1 g,62.17 g）、蛋比重（1.119,1.094）、蛋壳厚度（0.514 mm,0.311 mm）、哈氏单位（107.77,86.14）、蛋黄比例（38.12%,30.28%）、蛋壳比例（12.32%,11.19%）,以上指标鹅蛋均高于鸭蛋。鸭蛋蛋黄色泽优于鹅蛋,罗氏比色鸭蛋、鹅蛋分别为11.33和4.52。鸭蛋的血肉斑率达到12.5%,明显高于鹅蛋的3.57%,需要通过育种手段来降低。     

Moisture content and moisture quantity of sweated chicken eggs in 2 storage environments

There are instances where shell eggs may be moved from refrigeration into ambient temperature with high humidity, such as before wash and during transportation. Under these conditions, it is of concern that bacteria on wet eggs can grow and migrate through the shell pores into the egg. Objectives of this experiment were: 1) to compare 3 methods of quantifying condensate on eggs and 2) to quantify condensate on refrigerated shell eggs at 2 temperatures (22°C and 32°C). For objective 1, 270 fresh shell eggs (3 replications, 90 eggs per replication) were stored at 4°C, 60% relative humidity (RH), then placed at 22°C, 60% RH for 1 h. After this time, 30 pre-weighed eggs were randomly selected and weighed. Thirty eggs were thoroughly wiped with pre-weighed paper towels to collect condensate. Thirty eggs were evaluated with a pinless moisture meter for quantifying egg condensate, which was found to be an ineffective method. There was no difference in quantifying egg condensation by egg weight or weight of moisture absorbed on a paper towel (0.2% vs. 0.19% percentage gain mL condensation/egg surface area) (P > 0.05). For objective 2, 104 fresh eggs formed condensation at 2 temperatures (22°C and 32°C, 60% RH). Each egg weight was continuously recorded from the beginning of condensation formation to the point where the egg reached a constant weight. There was a difference found in the time it took for an egg to reach maximum condensation (11 min at 32°C, 17 min at 22°C), as well as completely dry (25 min at 32°C, 34 min at 22°C) between the 2 temperatures (P < 0.05).     

饲粮蛋白质水平对蛋鹌鹑产蛋性能的影响

采用单因子实验设计,将饲粮粗蛋白质设为3个水平,分别为18%、20%、22%,将鹌鹑分为6个组,每组4个重复,每个重复30只鹌鹑,实验阶段为33~40周龄,研究日粮中蛋白质水平对产蛋性能的影响.结果表明:第2组鹌鹑的产蛋量显著高于第1、3组(P<0.05),产蛋率显著高于第1、3组(P<0.05),第3组的平均蛋重显著高于第1、2组(P<0.05);第2组的料蛋比显著低于第1、3组(P<0.01).说明饲料蛋白质水平为20%时,产蛋性能是最佳的,提高蛋白质水平并没有促进鹌鹑的产蛋性能.     

Albendazole treatment in laying hens: Egg residues and its effects on fertility and hatchability

This work characterized the egg residual concentrations of albendazole (ABZ ) and its sulphoxide (ABZSO ) and sulphone (ABZSO ₂) metabolites and evaluated their effect on egg fertility and hatchability after ABZ treatments to laying hens. Seventy hens were allocated in groups: Group‐1 was the control without treatment; Group‐2 received a single ABZ oral dose (10 mg/kg); Group‐3, ‐4 and ‐5 were treated with ABZ in medicated feed over 7 days at 10, 40, or 80 mg kg^?1 day^?1, respectively. Eggs were analyzed to determine the ABZ /metabolite level by HPLC or subjected to incubation to evaluate the fertility and hatchability. Only ABZSO and ABZSO ₂ metabolites were quantified in egg after ABZ single oral administration with maximum concentrations of 0.47 ± 0.08 and 0.30 ± 0.07 μg/ml, respectively. ABZ and its metabolites were found in eggs after 7‐day ABZ treatments. The egg residue exposure estimated as AUC s (areas under the concentration vs . time curve) were 100.5 (ABZ ), 56.3 (ABZSO ) and 141.3 μg hr g^?1 (ABZSO ₂). ABZ administration did not affect the egg fertility at any dosages. Egg hatchability was not affected by ABZ treatment at 10 mg/kg in medicated feed, but it decreased when the dose was 4–8 times higher. These results should be considered when ABZ is used for deworming laying hens.     

Performance of Four Hybrids of Laying Hens in Modified and Conventional Cages

Abstract

In two trials, production, feed consumption, mortality, egg quality and birds' live weight of a total of 2877 caged laying hens of four hybrids, Dekalb XL, Lohmann Selected Leghorn (LSL) and Shaver 288 in Trial 1 and ISA Brown and LSL in Trial 2, were studied during full production cycles. The cage designs were Get-away cages (GA) with 15 hens per cage, a special version of the “Edinburgh modified cage” called “Modified and enriched cage” (ME) with 4 ISA or 5 Leghorn hens per cage, conventional cages of metal (CO) with 4 hens per cage and conventional cages of plastic (PL) with 3 hens per cage. GA and ME included nests, perches and sandbaths. LSL produced significantly better than the other hybrids. Shaver had a significantly lower live weight than Dekalb and LSL, while ISA was significantly heavier than LSL. Production in ME was similar to that in conventional cages and, in Trial 2, birds in ME, CO and PL produced significantly better than those in GA. The highest mortality was registered in GA, where in Trial 2 it was significantly higher than in ME. GA gave a significantly higher and CO a lower proportion of cracked eggs than ME and PL. In both trials ME gave significantly lower proportions of dirty eggs than GA and in Trial 2, the lowest. Few differences between the systems were registered regarding interior egg quality. It was concluded that ME is better for production, mortality and management than GA but similar to conventional cages.     

良种鸡与地方鸡杂交试验报告

利用不同品种的良种蛋鸡与本地地方鸡杂交,以提高地方鸡产蛋量、蛋重和淘汰鸡体重.试验Ⅰ、Ⅱ、Ⅲ、重组分别为湖北红鸡(?)×地方鸡(?)、地方鸡(?)×湖北红鸡(?),地方鸡(?)×罗曼褐商品代(?).第Ⅳ组为地方鸡(?)×地方鸡(?).试验结果表明:Ⅰ、Ⅱ、Ⅲ组与Ⅳ组相比,20周龄体重、42周龄体重、72周龄淘汰鸡体重、产蛋量、蛋重均能有效得到提高,其中42周龄体重和72周龄淘汰鸡体重Ⅰ、Ⅱ、Ⅲ组之间差异不显著,与Ⅳ组相比差异极显著,42周龄平均蛋重Ⅰ、Ⅱ、Ⅲ、组与Ⅳ组相比差异极显著,Ⅲ组与Ⅰ、Ⅱ组相比差异显著.42周龄单枚蛋重Ⅰ、Ⅱ、Ⅲ组与Ⅳ组相比分别增加7.4g、8.54g和10g,72周龄产蛋量Ⅰ、Ⅱ、Ⅲ组与Ⅳ组相比分别增加41、35,55枚.     

外源肌苷酸对种鸡产蛋性能、蛋品质及种蛋孵化性能的影响

本试验通过在种鸡的基础饲粮中加入肌苷酸(IMP)来研究其对种鸡产蛋性能、蛋品质和种蛋孵化性能的影响。选择遗传背景相同、体重相近,产蛋率达到5%的20周龄健康AA种鸡864羽,随机分为2组(对照组饲喂基础饲粮;试验组饲喂基础饲粮+0.5%肌苷酸),每组6个重复,每个重复72羽,试验期30 d。测定试验期间所有种蛋的平均蛋重、产蛋率和合格蛋率;每组随机选取部分种蛋进行蛋品质测定;于孵化开始第17天,通过照蛋处理统计种蛋受精率,第21天出雏时,计算受精蛋孵化率、入孵蛋孵化率和健雏率。试验结果表明:与对照组相比,试验组种鸡的平均蛋重、产蛋率和合格蛋率均有升高的趋势,但差异不显著(P>0.05);蛋形指数显著升高(P<0.05),蛋壳强度、蛋壳厚度和蛋黄颜色显著降低(P<0.05);受精率、受精蛋孵化率和入孵蛋孵化率显著升高(P<0.05),健雏率和雏鸡体重有升高的趋势,但差异不显著(P>0.05)。综上,0.5%外源肌苷酸对种鸡的产蛋性能和种蛋孵化性能均有促进作用。     

提高冷浸种成品良卵率的探讨

The coloured eggs from the silkworm varieties that are easy to occur noncoloured eggs were refrigerated and used in middle or late autumn,which could rule out noncoloured eggs completely,and could raise the percentage of good eggs and hatchability. This paper pointed out the optimum condition and time for refrigerating all sorts of coloured eggs.