褐稻虱长,短翅型产卵特性的比较

本研究在水稻不同生育期、不同抗性品种及不同温度条件下,对褐稻虱长、短翅型雌虫的产卵量和产卵前期进行了比较。试验结果表明,在16～33℃恒温和17.4～27℃自然变温范围内,长、短翅型雌虫在同一温度条件下产卵量差异不显著。在水稻的苗期、分蘖期和孕穗期,取食同一生育期植株的两种翅型雌虫产卵量也无显著差异。同在感虫品种或中抗品种上,不同规型雌虫的卵量也未表现显著的差异,只有在抗虫品种7105上,短翅型雌虫的卵量明显高于长翅型雌虫。此外,在22～31℃范围内,处在同一温度下短翅型雌虫的产卵前期显著短于长翅型雌虫。     

用人工寄主卵繁殖卵寄生蜂研究的新进展

本文报道用微电脑控制的卵寄生蜂人工寄主卵卡机样机研制成功。该机能将上膜、卵窝成形、注液、焊合、切断等5道工序在同一条自动线上连续操作,每小时能制1200张卵卡,可供生产600～700万头赤眼蜂之用。研究出2种新的防污剂(羊2号和羊3号)和减少细菌污染的综合措施,从而解决了在人工寄主卵上连代繁殖卵蜂的困难问题。通过连续40代的繁蜂试验,证明效果良好。1985～1987年在广东省番禺和顺德2县6100亩次蔗田上,用人工卵繁殖螟黄赤眼蜂防治甘蔗螟虫,寄生率达75～86％,与用柞蚕卵繁蜂释放的效果相似。     

Supplemental defatted microalgae affects egg and tissue fatty acid composition differently in laying hens fed diets containing corn and flaxseed oil

Effects of defatted microalgae (DFA) on fatty acid composition of eggs and tissues of hens have not been well studied. This experiment was to determine how low concentrations of supplemental DFA in the presence or absence of flaxseed oil (FO) altered fatty acid profiles of egg yolk, liver, adipose tissue, and plasma of layers. A total of 60 Shaver Leghorn layer hens (individually caged, 20-wk old) were allotted into 6 groups (n = 10) and fed a corn/soybean meal basal diet containing 0, 3, or 5% DFA and 0 (1.5% corn oil, CO) or 1.5% FO for 6 wk. BW, ADFI, egg production rate, and egg component weights were not affected by any of the dietary treatments at various time points, but egg yolk color was changed (P < 0.05) with increasing concentrations of DFA. The concentration of n-3 fatty acids in egg yolk and plasma were elevated by FO up to 9-fold (P < 0.05) starting at wk 1 or 2, and 39 to 83% (P < 0.05) by DFA. Supplemental DFA improved (P < 0.05) n-6/n-3 fatty acid ratios in egg yolk and plasma from 13 to 23 and 7 to 13, respectively, only in hens fed diets without FO. Fatty acid profiles of liver and adipose tissue (at wk 6) displayed responses to supplemental DFA and FO similar to those of egg yolk or plasma. In conclusion, supplemental 3 or 5% DFA caused moderate enrichments of n-3 fatty acids and decreased the n6/n3 fatty acid ratios of egg yolk and tissues in hens fed diets without FO.     

Effects of extruded flaxseed on layer performance,nutrient retention and yolk fatty acid composition

1. This study was conducted to determine the effects of feeding an extruded flaxseed (EF) on layer performance, apparent total tract nutrient retention (ATTR) and egg yolk fatty acid concentrations.

2. Seventy-two White Leghorn laying hens (58-week-old; three per cage) were randomly allotted to one of four dietary treatments: 0%, 7.5%, 15.0% and 22.5% of EF-supplemented diets for 8 weeks.

3. Supplementation with EF had no effect on feed intake, egg production, feed conversion ratio and egg weight. Egg components (yolk, albumen and shell percentages) were similar among treatments, except that shell percentage was greater for layers fed 22.5% EF than those fed 7.5% and 15% EF. The ATTR of dry matter and organic matter were highest for 0% and 7.5% EF, intermediate for 15% EF and lowest for 22.5% EF. Similar reductions on ATTR of crude protein and nitrogen-corrected apparent metabolisable energy were observed for layers fed 22.5% EF relative to those fed 0% or 7.5% EF.

4. Feeding EF at 7.5%, 15.0% and 22.5% of the diet markedly increased (by 92%, 198% and 271%, respectively) egg yolk concentrations of n-3 polyunsaturated fatty acid (PUFA) and reduced saturated fatty acid and n-6 PUFA concentrations.

5. It was concluded that omega-3 labelled eggs (300 mg/60 g of egg) may be produced with low (7.5% of diet) levels of dietary EF without compromising egg production parameters. However, feeding moderate to high levels of EF (i.e. 15% and 22.5% EF) may reduce total tract nutrient and energy utilisation.     

应用气流调控系统实施蚕种高密度催青的研究

以气流调控实施高密度蚕种催青感温外湿均匀，提高蚕种催青质量和房屋设备的利用率，起到节本增收作用。     

冷藏浸酸蚕种常温浸酸试验

通过对现行１０对主要蚕品种冷藏浸液蚕种采用常温浸酸的试验，得出在春制春、夏秋用蚕种采用常温浸酸法浸酸都可获得较高的实用孵化率的结果，可供生产应用。     

春期原种催青日期的确定

阐述了春期原蚕种催青日期确定的原则 ,列举了浙江省和全国主要蚕区历来春期原种催青开始日期