蜜蜂的寿命

社会性昆虫的特点是含有重叠世代的成年个体、级型分化体系(具繁殖功能及不具繁殖功能的个体分化)以及对幼龄个体的合作性照料。蜜蜂是社会性昆虫,不同级型的蜜蜂,发育时间及寿命不同。雄蜂的发育历期为24天,在春季及夏季的平均寿命为21~32天。某些情况下雄蜂可以至少存活59天。工蜂发育历期为21天,其寿命在不同的季节变化较大。夏季工蜂寿命平均为15~38天,春天和秋天平均为30~60天,冬     

小常识

蜂王的寿命为什么最长蜂王是蜂群中寿命最长的蜂,它的平均寿命可活到3—5年,最长可活到8年。而工蜂的平均寿命仅能活两个月,在越冬的时候最长也只能活6个月。为什么同样是蜜蜂,寿命有这样大的差别呢?原来蜂王吃的食物和工蜂不同,     

蜜蜂度夏延寿之我见

夏季羽化的工蜂平均寿命只有33天，而秋季羽化的工蜂平均寿命达154天。为什么两者的寿命相差将近五倍呢？主要是天气和环境因素，夏季天气炎热，蜜粉源稀少，工蜂整天忙碌采水和振翅扇风，体能消耗大，而秋季风调雨顺，天气凉爽，蜜粉源丰富，工蜂新陈代谢缓慢，体内蛋白质消耗少，所以寿命延长。那么，蜜蜂怎样度夏才能延寿呢？     

维生素B_2对中华蜜蜂工蜂寿命及学习记忆能力的影响

本试验旨在研究维生素B_2对中华蜜蜂工蜂寿命及学习记忆能力的影响。试验分为工蜂饲养试验和学习记忆试验2部分。工蜂饲养试验:将1日龄中华蜜蜂工蜂分成3组,每组5个重复,每个重复约200只。对照组(Ⅰ组)饲喂1∶1的糖水,2个试验组在1∶1糖水的基础上分别添加100(Ⅱ组)、400 mg/kg(Ⅲ组)的维生素B_2,每天记录各组工蜂的死亡情况,直到全部死亡。工蜂学习记忆试验:分组方法同工蜂饲养试验,并按照工蜂饲养方法对1日龄工蜂喂养7 d后,利用吻伸反应方法测定工蜂短时学习记忆及长时学习记忆能力,并通过荧光定量PCR检测学习成功后工蜂学习记忆相关基因的相对表达量。结果表明:工蜂的平均寿命随维生素B_2添加量的升高而延长,而且试验组(Ⅱ组、Ⅲ组)的平均寿命显著高于对照组(P0.05),但Ⅱ组与Ⅲ组间差异不显著(P0.05)。Ⅲ组工蜂的长时学习记忆及短时学习记忆能力均显著高于对照组和Ⅱ组(P0.05),而且Ⅱ组工蜂的长时学习记忆能力也显著高于对照组(P0.05)。Ⅲ组工蜂的多巴胺受体基因2(Acdop3)、c AMP反应元件结合蛋白(Ac CREB)相对表达量均显著高于对照组和Ⅱ组(P0.05),而且Ⅱ组工蜂的Acdop3相对表达量也显著高于对照组(P0.05)。由此得出,维生素B_2影响中华蜜蜂工蜂的寿命及学习记忆能力,在人工饲喂蜂群时需要提供适量的维生素B_2。     

电取蜂毒对中华蜜蜂寿命的影响

采用QF—1型电子取毒仪,分别电刺激3～27日龄的中蜂工蜂5分钟,结果3和6日龄的工蜂寿命缩短差异不显著(P>0.05);9、12、15、18日龄的工蜂寿命缩短2.75～4.59天,差异显著(P<0.05);21、24、27日龄的工蜂寿命缩短4.50～4.75天,差异极显著(P<0.01)。     

蜜蜂的行为和环境（二）

(续上期)二、蜜蜂的寿命蜜蜂是一种“社会性”昆虫。群居蜜蜂的行为,和环境表现出高度的统一性,使得蜂群的寿命,从理论上可以说是无限长的,因为作为“母亲”的蜂王,其寿命长到可和它的后代“子女”在一个蜂房里同居一代、两代甚至几代。但是,就蜂群中的每一蜜蜂个体来说,寿命则相当短促。蜂王的寿命最长,平均寿命一般为3年,也有记录达到8年的;雄蜂在夏季最长寿命为59天,在冬季于无王蜂群中可存活更长一些;工蜂在具有蜂王的正常蜂群中,越夏寿命约为25～35天,最长不超过60～70天,越冬蜂的寿命最长可到304天,一般略多于4～5个月。     

蜜蜂的哺育行为

<正>工蜂能够识别蜂子的发育状态、性别及级型是进行适当的蜂子哺育及幼虫饲喂的先决条件。工蜂能够辨别三种级型的幼虫。雄蜂、工蜂及蜂王幼虫的食物组成是不同的,说明工蜂可以辨别幼虫的级型。工蜂的饲喂行为与幼虫食物组成随幼虫日龄发生变化,说明哺育蜂可以识别幼虫的日龄。此外,工蜂似乎还可以在其检查工程中确定幼虫的食物需求。     

Royalactin诱导幼虫发育成蜂王

影响蜜蜂级型分化的决定因子是什么？这是科学家非常关注的问题。工蜂和蜂王都是由受精卵发育而成，只因发育过程中所处的环境和食物不同而引起巨大差异，蜂王的个体大小约是工蜂的1．5倍，而寿命更是工蜂的约20倍。此前的研究表明，蜂王与工蜂两型分化的形成是由它们进食的蜂王浆决定的，但是，蜂王浆中的何种成分促使幼虫变身蜂王，一直是个谜。     

关于采集蜜蜂蜂毒几个问题的观察

1990年5～9月用“封闭式蜜蜂蜂毒采集器”进行采集蜂毒试验,结果表明:在正常情况下,采毒后的工蜂损失率为1～2％。20日龄工蜂采毒后平均寿命缩短3.08天。采毒后的工蜂经2个小时的恢复后才能出巢采集,采毒后的工蜂还可再次采毒,10框、12框、15框蜜蜂群势的蜂群,分别产蜂毒0.425克、0.575克、0.7克,以每克蜂毒60元计算,投入每个人工生产蜂毒的产值为29.67元,每群每天生产蜂毒的平均产值为1.19元。     

貂、狐预产期的计算方法

一、蜂群基础知识 (一)蜂群的组成 当你在春暖花开的季节观察蜂群时,你不难发现在蜂群中有形态各异的蜂王、雄蜂和工蜂三型蜂。 1.蜂王:蜂王(题图中)是蜂群中最长者,约20～25毫米,体重约300毫克。在正常的蜂群中只有一只蜂王。蜂王腹部比工蜂、雄蜂发达,而翅膀却短而窄,只能盖住其腹部的1/2～2/3。蜂王的口器已经退化,必须完全由工蜂来饲喂。     

Genetic analyses of scrotal circumference size and growth in Rambouillet lambs.

The objectives of this study were to identify nongenetic factors influencing scrotal circumference size and growth and to estimate heritabilities of scrotal circumference size at different ages and scrotal circumference growth between ages. Data on scrotal circumference, live weight, and age were recorded over 6 yr (1982 to 1987) on 541 spring-born Rambouillet ram lambs (109 sires, 307 dams) at the Dixon Springs Agricultural Center. Scrotal circumference and live weight were predicted at four ages (90, 120, 150, and 180 d) for each lamb. The two models used to evaluate factors affecting scrotal circumference size at fixed ages were the same except for the addition of live weight and live weight squared to one of the models. Likewise, the two models used for scrotal circumference growth between ages were the same except for the addition of live weight change and live weight change squared to one of the models. Year and type of birth were significant sources of variation for both traits under both models. Regression coefficients for live weight and live weight squared on scrotal circumference size and for live weight change and live weight change squared on scrotal circumference growth and for day of birth within year for both traits were generally different from zero (P less than .05). Heritability estimates for scrotal circumference size at fixed ages ranged from .19 to .41. Adjustments for live weight led to an average 41.5% increase in heritability estimates. For scrotal circumference growth, heritabilities ranged from .17 to .60 and adjustments for live weight change resulted in an average 13% decrease in estimates.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of cellulase on calves fed an acidified milk diet]

The purpose of this research was to establish the influence of 3 j Cx cellulase applied per gram of COT concentrate mixture, fed in combination with a milk diet acidified by formic acid to the value of pH 4.6, on calf growth performance in one metabolism and two field experiments. In the metabolism experiment two groups of calves, with six animals in each, were fed acidified whole milk, which was diluted stage by stage till weaning at 60 days of age. The average live weight gain in the control at the end of the milk feeding period, i.e. from 14 to 60 days of age, was 29.90 kg. This corresponds to a daily live weight gain of 0.650 g. The total live weight gain of male calves in the experimental group was 29.30 kg, corresponding to a daily live weight gain of 0.638 g (Tab. I). Tab. II shows the average feed and nutrient intakes per kg live weight gain. The calves which received the enzyme supplement tend to have the higher feed conversion rate. During the forage feeding period, i.e. from 61 to 90 days of age, the average daily live weight gains were 1.10 kg and 0.980 kg in the control and experimental groups, respectively (Tab. III). The average live weight of 90 days old male calves was 107.70 kg and 103.90 kg in the control and experimental groups, respectively. The amount of consumed nutrients (digestible protein and starch units); in relation to the total feed intakes, is lower in the experimental groups, which proves the higher feed conversion rate (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

窝产活仔数和初生重与仔猪早期断奶重及成活率的相关性研究

为研究猪窝产活仔数与初生仔猪个体重对21日龄早期断奶仔猪个体重及成活率的相关性,特选择一大型规模猪场2～6胎母猪在1个月内所产的118窝计1350头仔猪作为试验对象,要求所有初生仔猪均由亲本母猪带仔哺乳,且按窝产活仔数不同（6～17头）分组测定仔猪初生个体重和21日龄早期断奶仔猪窝个体均重,并观察断奶成活率,同时对其相关性状作方差及回归分析。结果表明,不同组间初生仔猪窝个体均重和21日龄早期断奶仔猪窝个体均重及断奶成活率差异显著（P〈0．05）;窝产活仔数对初生仔猪窝个体均重和21日龄早期断奶仔猪窝个体均重及断奶成活率呈极显著的负相关（R=-0．802、-0．851、-0．698,P〈0．01）;初生仔猪窝个体均重对21日龄早期断奶仔猪窝个体均重及断奶成活率呈极显著的正相关（R=0．837、0．741,P〈0．01）。试验结果表明,窝产活仔数越多,初生仔猪个体就越小,早期断奶也越轻,成活率也低;初生仔猪个体越大,早期断奶就越重,成活率也越高。只要通过科学合理的方法,适当控制猪窝产活仔数并提高初生仔猪个体重,能有效提高早期断奶仔猪的生长速度,并可获得更好的经济效益。     

波德代种公羊精液品质的分析

选取健康、体况良好、体格大小相近的波德代种公羊6只,分为运动与不运动两组,试验期6d,研究运动状态对绵羊精液品质的影响.结果表明：波德代种公羊平均每次采精量为1.33土0.08 mL,平均精子活率84.24±1.76,平均密度为38.06±2.55亿个/mL,精子畸形率平均为2.64±0.23％.在公羊运动与不运动状态下活率之间差异显著（P＜0.05）,而射精量、畸形率、密度之间差异不显著（P＞0.05）;对精液品质特性进行相关性分析发现精子密度与畸形精子率呈显著负相关（P＜0.05）,其他指标之间相关性不显著（P＞0.05）.     

胎次与产仔数对广东小耳花猪初生仔猪均匀度的影响

初生仔猪均匀度常用窝初生个体均重的标准偏差及变异系数表示,是反映母猪孕期繁殖效率的重要指标之一。为了研究不同胎次及产仔数对初生仔猪均匀度的影响,研究对1011窝广东小耳花猪的历史分娩数据进行分析。结果表明:窝初生个体均重为0.67 kg,窝初生个体均重的标准偏差为0.13 kg,窝初生个体均重的变异系数为19%;窝初生个体均重与窝初生个体均重标准偏差的相关系数是0.296,呈极显著正相关(P约0.01);窝初生个体均重变异系数与总产仔数的相关系数是0.028,与产活仔数的相关系数为0.024,均呈现弱正相关。研究建议在地方猪开发利用中,合理调整群体胎龄结构,改善饲养管理方式,合理调整孕期母猪营养水平,进一步提高群体初生仔猪均匀度。     

微贮秸秆与秸秆育肥羊只的比较试验

秸秆微贮后 ,秸秆发生了质的变化 ,这一变化 ,提高了饲草利用价值和适口性 ,加快了羊只增重。试验将秸秆微贮技术引入景泰 ,通过微贮秸秆和未微贮秸秆育肥羊只进行对比 ,结果表明 ,在 6 0 d育肥期内 ,秸秆微贮料育肥羊平均日增重 4 4 .8g,对照组日增重 7.1g,提高 5.3倍     

微贮秸秆与秸秆育肥羊只的比较试验

秸秆微贮后,秸秆发生了质的变化,这一变化,提高了饲草利用价值和适口性,加快了羊只增重.试验将秸秆微贮技术引入景泰,通过微贮秸秆和未微贮秸秆育肥羊只进行对比,结果表明,在60d育肥期内,秸秆微贮料育肥羊平均日增重44.8g,对照组日增重7.1g,提高5.3倍.     

Oral and intramuscular ferric dextran administration in male rearing calves. 5. Live weight gain during maintenance in fluid feed and weaning ranges

195 rearing calves, which immediately after their gathering from various dairy farms had an anaemia frequency of 57.4% and an average age of 22 d and an average live weight of 43 kg, were at random divided into 3 groups and received in addition to the iron in the rations oral (B), intramuscular (C) or no (A) ferridextrane applications during their 56-day stay in the fluid feed range of a rearing farm. The average live weight gain of the calves during these 56 days in groups A, B, and C was 882 +/- 171, 949 +/- 145 and 912 +/- 170 g/d resp. and during the 57-day stay in the weaning range 664 +/- 205, 715 +/- 222 and 670 +/- 226 g/d resp. The significant advantage in the development reached by the calves in group B over those in group A during their stay in the fluid feed range did not get lost after the change to the weaning range. Based on the cost of medicine and on the development of the live weight of the calves in the 3 test groups in the fluid feed and weaning ranges the economic effect of ferridextrane applications was calculated. Under the rearing conditions given, iron intervention proved to be sensible for both health and economic reasons.     

Operation-management factors associated with early-postnatal mortality of US foals

Of 7320 equine foals reported born alive during 1997 on 1043 operations that had equids on 1 January 1997, and that participated in the United States National Animal Health Monitoring System (NAHMS) Equine 1998 Study, 120 foals were reported to have died (by either euthanasia or natural causes) within the first 2 days of a live birth. The weighted estimate was 1.7% mortality (standard error=0.5) within the first 2 days of live birth for all foals born on operations in the 28 states included in the study.A multivariable logistic-regression model revealed that foals born in the southern region were more likely to have been reported to have died within the first 2 days of live birth than in the western region. In addition, the following operation-level factors were associated with increased odds of a foal dying within the first 2 days of live birth: not routinely testing newborn foals for adequate absorption of colostral immunoglobulins during the first 2 days of life; adding new resident equids to the operation during 1997; having non-resident equids stay on the operation for 1-30 days during 1997; never requiring an official health certificate (for operations that had non-resident equids stay on the operation for 1-30 days); using something other than straw or hay as the predominant bedding type; and feeding equids a vitamin-mineral supplement/premix with forage and/or grain.     

A Survey of Small-scale Broiler Production Systems in Botswana

Aspects of husbandry, productivity parameters, diseases, marketing and farmer attitudes in small-scale broiler farms in Botswana were studied using a questionnaire-based survey. The number of broilers per production cycle in small-scale operations ranged from 100 to 2000, with an average of 640. On average, small-scale producers had 4-5 production cycles per annum with an interval of 2-3 weeks between batches. The average marketing age was 48.3 days at a live weight of 1.79 kg and a carcase weight of 1.42 kg. The average feed conversion ratio was estimated to be 2.72 (kg feed/kg live weight) and the average mortality was 9.15%. Overall, the performance indices of broilers under small-scale farm conditions were much poorer than those obtained elsewhere under improved management conditions, but these lower performance levels are suggestive of the potential that exists for further improvement. The survey also identified several areas of concern that constrain the realization of the full potential of this sector. Factors contributing to the poor performance under small-scale farm conditions are complex, but feed supply and quality, chick quality and farmer training appear to be areas for immediate improvement.