桑蚕两广二号蚕种延期冷藏实用化探讨

探索延期冷藏两广二号桑蚕种的有效时间和最适贮藏方法，可以提高生产中大量延期冷藏种的利用率。对已经冷藏160d．320d两广二号蚕种进行延期冷藏调查研究，试验中对蚕种设计了单式冷藏浸酸、单式冷藏不浸酸、复式冷藏浸酸、复式冷藏不浸酸区等处理方式。主要调查了实用孵化率、绝食80h蚁蚕生命率。结果表明延期冷藏蚕种孵化率随着冷藏时间增加而呈下降趋势，不浸酸区孵化率稍高于浸酸区，复式冷藏孵化率稍高于单式冷藏。     

浸渍消毒桑叶冷藏处理对两广二号原种良卵率的影响

采取漂白粉消毒浸渍并冷藏保鲜桑叶是蚕种繁育中常用的一种桑叶处理方式。为了了解饲喂经消毒浸渍后冷藏保鲜的桑叶对家蚕良卵率的影响,试验使用漂白粉消毒液浸渍消毒后并放置在12～15℃冷库中进行冷藏保鲜的桑叶,饲喂两广二号4个原种亲本芙蓉、932、湘晖、7532,分别调查4个原种母蛾的良卵率。试验结果表明,两广二号原种处理组与对照组的母蛾良卵率总体均值并无显著差异,蚕种繁育中使用消毒并冷藏处理的桑叶饲喂家蚕对制种成绩无影响。     

家蚕新品种桂蚕N2一代杂交种繁育效果与技术探讨

通过对2012年秋—2015年秋4年春夏秋多月份共11批次对家蚕新品种桂蚕N2的杂交原种进行饲养繁育一代杂交种,探讨该品种的繁育效果与技术。结果表明,原种茧平均死笼率NC99R·NC9C、NJZ·NJ7分别为3.09%、5.39%,NC99R·NC9C与同期两广二号中系原种932·芙蓉相比明显降低,差异极显著,NJZ·NJ7与同期两广二号日系原种7532·湘晖相比差异不显著;张原种制种量正交种为61.89张,比同期两广二号提高14.85%,正交品种间有极显著提高,反交种为35.41张,反交品种间差异不显著;平均公斤茧制种量正交种、反交种分别为3.36张、2.66张,与同期两广二号相比正交种差异不显著,反交种差异显著。只要根据新品种的特性要求进行繁育,采取合理的技术措施,掌握好对交品种的出库、收蚁日差(日系比中系早3~4d);加强提青分批,淘汰弱小蚕;稀座;良桑饱食;中系品种提早1 d收茧、削茧;适量投蛾,加强巡蛾等,就能获得良好的繁育成绩。     

家蚕冷浸种不同胚子再冷藏期限的试验

试验表明．含多化性血统的“两广二号”家蚕普通种冷藏120天出库浸酸后，丙胚子再冷藏40天，丁，或丁：胚子再冷藏30天，戊，至戊：胚子再冷藏20天，己。至己，胚子再冷藏10天，其孵化率和蚊蚕生命力，均有实用价值。各胚子超过此期限越长，孵化率和蚁蚕生命力越弱。     

夏秋用家蚕品种两广二号在葫芦岛蚕区的引繁试验初报

为了解夏秋用家蚕品种两广二号原种在葫芦岛蚕区的繁育特性,2015年秋季辽宁省葫芦岛市前所蚕种场以871、872原种(871A·871B、872A·872B)为对照,在相同饲养条件下对引进的两广二号原种(932·芙蓉、7532·湘晖)进行了繁育比较试验。试验结果显示:与871A·871B、872A·872B相比,932·芙蓉、7532·湘晖的实用孵化率分别高0.3个百分点和0.1个百分点;全龄经过分别短19 h和14 h,蔟中经过均短1 d;发病率分别低0.21个百分点和0.04个百分点;克蚁收茧量分别高0.10 kg和0.16 kg;公斤茧制种量分别高0.5盒和0.4盒。表明两广二号原种在葫芦岛蚕区具有实用孵化率略高、发育经过短、蚕期发病率低和繁育系数高的优点,具有很高的推广价值。     

932雄蛾冷藏处理对原种质量的影响

桑蚕品种932和芙蓉是两广二号的两个中系亲本。在原种繁育过程中因出现932羽化齐一,而芙蓉羽化分散的情况,使芙蓉母蛾与932雄蛾对交经常需要冷藏932雄蛾,但932雄蛾的不耐冷藏性会使杂交原种芙蓉×932出现空圈多、有效卵圈少、蚕种净种率低等问题。为探究冷藏处理932雄蛾对蚕种质量的影响,调查了在不同冷藏温度、冷藏时间条件下处理932雄蛾后芙蓉×932的蚕种表现。试验结果表明:冷藏温度和冷藏时间对有效卵圈数有显著影响,932雄蛾冷藏温度越低、冷藏时间越长,则芙蓉×932的蚕种表现越差;对不良卵率和良卵量的影响因交配的芙蓉雌蛾的出蛾时间不同有差异;932雄蛾最佳冷藏条件为5℃、24 h。     

桂蚕2号杂交原种浸酸后再冷藏试验

为探索桂蚕2号杂交原种浸酸后再冷藏的期限，本试验调查了桂蚕2号杂交原种浸酸后再冷藏不同时间的蚕种实用孵化率及蚁蚕绝食生命力情况。试验结果表明：各品种浸酸后耐冷藏能力和蚁蚕绝食生命力都不同，中系较日系耐冷藏。932×8810、8810×932、8711×7532浸酸后再冷藏安全期限分别为40d、30d、20d。     

家蚕两广二号原种滞育卵不同冷藏时间浸酸技术研究

以家蚕两广二号秋制原种滞育卵为研究对象开展滞育卵不同冷藏时间的浸酸技术研究。试验设计入库前保护30 d后,在2.5~5.0℃的内库分别冷藏10 d、20 d、30 d、40 d、50 d、60 d、70 d、80 d、90 d后出库浸酸,浸酸标准为盐酸比重1.094,液温47.8℃,在3~28 min时间范围内,每个冷藏分20个不同浸酸时间处理,调查催青经过和实用孵化率。结果表明:4个品种均表现出冷藏时间过短,蚕种实用孵化率偏低、成绩不稳定。随着冷藏时间的延长,在适浸范围内,蚕种发育趋于整齐,孵化、催青经过逐步缩短,实用孵化率提高。同一冷藏时间内,浸酸刺激过量导致蚕种发育变慢,实用孵化率呈现下降的趋势。冷藏10~20 d,中系原种实用孵化率随着浸酸时间增加而增加,日系原种实用孵化率随浸酸时间增加无明显变化。生产上如要提前出库用种,中系原种建议冷藏时间50 d以上,日系原种建议冷藏时间70 d以上。浸酸标准为盐酸比重1.094,液温47.8℃。中系原种的浸酸时间分别为:冷藏50 d,浸酸时间13~14 min;冷藏60 d,浸酸时间9~10 min;冷藏70 d,浸酸时间9~10 min;冷藏80 d,浸酸时间7~8 min;冷藏90 d,浸酸时间6~7 min。日系原种的浸酸时间为:冷藏70 d,浸酸时间9~10 min;冷藏80 d,浸酸时间8~9 min;冷藏90 d,浸酸时间7~8 min。     

两广二号新品系一代杂交种繁育试验

为进一步了解经复壮改良后形成的两广二号新品系的繁育性能,对两广二号新品系进行一代杂交种繁育试验,比较新品系的发育经过、种茧调查成绩及繁育成绩.结果显示,两广二号新品系原蚕发育比较快,日系7532×湘晖(新)的龄期经过比7532×湘晖缩短2 h,中系932×芙蓉(新)的龄期经过比932×芙蓉缩短3 h.两广二号新品系原蚕...     

越年蚕种延期冷藏试验初报

本试验将原计划春制越年春用或秋制越年春用的一代杂交种,延期冷藏到夏季(第2期冷藏90d)出库催青、饲养,其实用孵化率、催青死卵率及1-2龄饲养成绩等主要指标与对照种比较没有显著差异。     

蚕种丙1胚胎有效冷藏期的探讨

本试验根据孵化率研究结果：我省现行蚕品种丙１胚胎冷藏期春制越年种１００日，秋制越年种１１５日，浸藏浸酸种８０日，即时浸酸种５０日，可在生产上使用。     

秋制越年种超限冷藏的孵化试验

秋制越年种丙1胚子起超限冷藏,可缓解夏秋蚕供种不足的矛盾,现行品种超限冷藏符合生产要求,试验结果显示:复式冷藏种丙1,胚子可安全冷藏80天,三次冷藏种丙1胚子可安全冷藏70天。     

家蚕雌蛹冷藏对人工孵化处理蚕种质量的影响

家蚕蛹期冷藏是蚕种生产上普遍使用的方法。苏5×苏6(正反交)和苏菊×明虎(正反交)等江苏省现行蚕品种,羽化前日的雌蛹冷藏对蚕种质量有显著不良影响,主要表现为不受精卵率增加,孵化率和孵化整齐度下降。10℃冷藏的影响程度显著超过5℃冷藏,冷藏4d的影响显著超过冷藏2d。雌蛹冷藏对冷藏浸酸卵的孵化率影响显著大于即时浸酸蚕卵,结果显示应避免冷藏家蚕雌蛹,如无法避免,应该尽量将生产的蚕种作即时浸酸使用。     

应用三段冷藏法冷藏越年夏用蚕种

近两年来本库应用三段冷藏法冷藏夏用蚕种２８万张，实践证明三段冷藏夏用蚕种延长到早中秋孵化率仍能保持高水平，具有生产实用价值，从不同中期别和不同类别蚕品种，平均孵化率春制９７％以上，秋期９８％以上，符合生产要求。     

Hatching success and embryonic mortality on lesser rhea (Pterocnemia pennata) farms in northern Patagonia, Argentina

1. The hatching success and embryonic mortality of 724 lesser rhea eggs from 12 farms in northern Patagonia, Argentina were monitored during the 2000 breeding season. 2. Average infertility was 24.5%, embryonic mortality was 33.5%, hatchability of fertile eggs was 66.5% and the neonatal mortality was 57.0%. There were large variations between different farms. 3. Bacterial contamination was high and egg hatchability was also affected by the occurrence of oedematous and malformed embryos. 4. No significant relationships were found between embryonic loss, duration of egg storage, initial egg weight or weight loss of hatched and failed eggs. 5. The low productivity on lesser rhea farms is caused not only by embryonic mortality but also by a high incidence of infertile eggs and neonatal mortality. 6. Bacterial infection may not have been the most important cause of incubation failure, indicating that nutritional deficiencies and inbreeding may play an important role in the productivity of these farms.     

Effect of breeder age and breeding season on egg production and incubation in farmed ostriches

(1) This research was carried out to investigate changes in egg production and hatchability as influenced by age and breeding season of 10 trios (two females, one male) of ostrich (Struthio camellus) during 1998 to 2002. (2) Breeding season affected number of eggs laid per female per season, average egg weight, length of laying period and clutch sequence. (3) The number of eggs laid per female per season was 25 in the first breeding season and 57 by the fifth breeding season. The laying period lasted 169 d in the first season whereas it was 210 d by the fifth season. The breeding season became longer year by year. (4) The number of clutches was two in the first season, three in the second and 4 in the later breeding seasons: the mean interval between cycles was 9 to 10.6 d and the mean number of eggs in one cycle varied from 12 to 14.4. (5) The breeding season affected the hatchability of fertile eggs, chick weight at hatching, hatchability of total eggs, fertility, malpositioned embryos, deformed chicks and assisted chicks during hatching. The first 4 variables increased and the last three decreased, with each breeding season. (6) Weight loss of eggs and length of incubation were unaffected by the breeding season. Hatchability which was 64.3% in the first season increased progressively and reached 73.1% in the fifth breeding season.     

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.     

Egg storage and breeder age impact on egg quality and embryo development

Prolonged hatching egg storage (>7 days) influences internal egg quality and embryo survival during both storage and subsequent incubation. Moreover, effects of storage of hatching eggs interact with the breeder age. The aim of this review was to investigate how this interaction between storage duration and breeder age affects egg, embryo, hatchling and chicken characteristics. Prolonged storage resulted in a reduction in egg quality in both young and old breeders. This reduction was more pronounced in young flocks than in older flocks. For example, albumen pH increased more after 8 days of storage in younger flocks than in older flocks. Additionally, the embryonic morphological stage appears to increase as well with storage duration, but this increase is again more pronounced in younger flocks than in older flocks. Short storage (<7 days) seems to increase hatchability of eggs from young breeders, probably as a result of albumen liquefaction with consequently better oxygen availability for the embryo. However, long storage (>7 days) resulted in a decline in hatchability, which was stronger in older breeders than in younger breeders. Prolonged storage duration resulted in lower chicken quality in both young and old breeders, but interaction between storage duration and breeder age on multiple chicken quality parameters is not clear. Based on this review, it can be concluded that (a) Short storage can improve hatchability of eggs from young breeders, but not from older breeders. (b) Negative impact of long storage appears to be lower with young breeders than with old breeders. (c) Adapted storage conditions related to the age of breeders might be an option to reduce negative effects of prolonged storage on hatching egg quality and chicken quality.     

家蚕种水中浸渍安全期限试验

本试验对“两厂二号”不同用种期别的杂交种进行了水中浸渍安全期限研究。结果得出三种生产用种的水浸安全期限为：即浸期种0．5日，滞育期保护种1．5日，冷藏期种2日。     

Effects of some egg characteristics on the mass loss and hatchability of ostrich (Struthio camelus) eggs

1. This study was conducted to examine some egg characteristics and determine the effects of eggshell thickness and eggshell porosity on water loss and hatchability of eggs in ostriches. 2. Shell thickness did not correlate significantly with hatchability. However, eggs of low shell thickness lost more mass (13.03%) than those with intermediate (11.22%) and high (10.36%) shell thickness. Mass loss during incubation was higher in hatched (11.98%) than unhatched eggs (11.09%). Shell thickness was negatively correlated to egg mass loss (r = -0.65). 3. The pore density was correlated with hatchability. Hatchability was 50% lower in eggs with low pore densities (40.93%) than with high densities (80.94%). Pore density was positively correlated with egg mass loss (r = 0.63). Incubation mass losses of hatched and unhatched eggs were not significantly different. 4. Mean eggshell water vapour conductance (G) value and shell conductance constant (k) were 87.77 +/- 4.21 mg H2O/d/Torr and 2.44 respectively (n = 15). 5. Because of eggshell functional properties and resulting low egg mass loss hatchability is low when ostrich eggs are artificially incubated. The mass of eggs used in the experiment was relatively high and their eggshell water vapour conductance was low. As a result, egg incubation mass loss was lower than it should be. It is concluded that incubator humidity should be low (25%) to allow enough mass loss during incubation from the eggs.