Relationships between sulfur concentration in mulberry Leaves and the quality of silkworm cocoon

A 40-day gnotobiotic microcosm experiment was carried out to quantify the effect of bacterial-feeding nematode on plat growth and nutrient absorption.The results showed that inoculation of bacterial-feeding nematode Protorhabditis sp.stimulated the growth of wheat (Triticum aestivum) and the uptake of N.By the end of the 40-day incubation wheat biomass and N uptake in the treatment with nematode and bacteria (Pseudomonas sp.)increased by 6.5% and 5.9%,respectively,compared with bacteria alone treatment.The presence of nematode mainly accelerated the growth of aboveground of wheat,while it slightly inhibited the root development.There was little difference in plant tissue N concentration between treatments.P concentration and uptake of wheat,however,were generally reduced by nematode, It appears that the enhancement of plant growth and nitrogen uptake is attributed to the enhancement of nitrogen mineraliztion induced by nematode feeding on bacteria,and the reduction of phosphorous uptake is the result of ewak root status and comptetition by bacteria immobilzation.     

巷道式孵化的工艺技术探讨

巷道式孵化以其独特的气流方式区别于厢式孵化。巷道式孵化器的气流把含氧量最多的新鲜空气带给老的胚胎，把各阶段老胚胎释放的热量又供给需热的各阶段胚胎的发育，并始终保持着理想的设计温度。因而，所需功率相对较小，且孵化容量大，可以节约大量的能源，具有良好的经济性。讨论了进行巷道式孵化的孵化厅布局及孵化操作技术。中国农业大学正大肉鸡发展中心采用巷道式孵化器对７批艾维茵父母代种鸡的３２０万枚种蛋进行孵化，获得了优异的孵化成绩，受精蛋孵化率平均为９４．７５％，入孵蛋孵化率平均为８５．６７％，健雏率平均为９８．２８％。     

淮南麻黄鸡20周龄体重对早期产蛋性能的影响

将308只淮南麻黄鸡按照20周龄体重以100g为组距从小到大分为5组,分析各体重组与开产蛋重及产蛋前期产蛋率、蛋重和种蛋合格率之间的关系,以确定淮南麻黄鸡20周龄体重的适宜选择标准.结果表明,20周龄体重与开产蛋重呈正相关,在22～35周龄,第3和4组的产蛋率增幅最大,维持时间较长;第1、2、3和4组蛋重增加比较平稳,第5组平均蛋重比第1、2和3组分别高11.05％、9.72％和8.61％(P＜0.05);第3和4组的平均种蛋合格率较高,第3组的平均种蛋合格率比第1组高5.18％(P＜0.05).总体而言,第3和4组能够提供较多的合格种蛋数,淮南麻黄鸡的20周龄体重宜控制在1241～1 440 g之间.     

基于机器人的禽蛋自动检测与分级系统集成开发

将禽蛋的破损检测、内部品质检测以及检测和分级时的搬运工作集成到一个关节型机器人上,实现了禽蛋检测与分级的自动化和柔性搬运.机器人在视觉引导下,定位禽蛋位置并将其吸取,分别运动到基于敲击声音的破损检测和基于彩色图像的内部品质检测装置处,进行相应的检测,根据检测结果分级并将禽蛋搬运到相应等级的位置放下.文章给出了各子系统的组成结构、集成原理,硬件配置和主要参数.试验结果表明,该系统硬件配置合理,各部分能够协调工作,运行稳定.     

What do artificial nests tells us about nest predation?

Artificial nests are commonly used to evaluate predation, but the assumption that this method mimics predation on natural nests has seldom been tested. Natural and artificial nests of eastern yellow robins (Eopsaltria australis) were monitored in four, 55-ha plots over two breeding seasons. Overall, daily survival rates were higher (P<0.001) for natural (95%/day) than for artificial nests (88%/day). Among plots, daily survival rates for the two types of nests were not correlated with one another (P=0.72) indicating that the spatial pattern of predation on artificial nests did not mimic that for natural nests. Seasonal variation was evident for natural nests in one year, when they were more successful at the beginning and end of the breeding season. No seasonal patterns were observed for artificial nests in either year. Neither natural nor artificial nests showed annual variation in predation. Previous researchers concluded that large birds were important predators on robin nests. In this study, predation by large birds on artificial nests was positively correlated with the numbers of large birds counted on the plots (P=0.04). However, large birds depredated only 16% of artificial nests. Daily survival rates for artificial nests were recalculated using predation by large birds only. These rates were compared with natural nests, but there was still no correspondence in the spatial and temporal patterns of predation for the two types of nests. These results suggest that inferences about predation on natural nests based on artificial nest studies should be avoided.     

稳定同位素指纹分析在蚕茧产地溯源中的应用研究

蚕茧产地溯源是丝绸原产地溯源的基础.本研究为了探究蚕茧产地溯源最适方法,以不同产地的蚕茧为研究对象,利用不同产区蚕茧的13C、15N、18O和2H同位素组成,通过单因素方差分析、多重比较分析、Fisher线性判别分析留一法交叉验证,最后建立蚕茧产地溯源模型.单因素方差分析结果表明,不同产地蚕茧的δ13C、δ15N、δ1...     

不同CO2浓度下鸡蛋呼吸仿真分析及验证

贮存环境中CO2浓度对鸡蛋呼吸作用及新鲜度变化具有重要影响,为了进一步考察在不同CO2浓度下鸡蛋呼吸释放CO2的扩散及新鲜度变化情况,该研究测定贮存在温度为25℃、相对湿度为65％、CO2体积分数分别为1.5％、3.0％、4.5％及空气(对照组)环境下鸡蛋呼吸和新鲜度,利用FLUENT软件完成不同CO2浓度下鸡蛋第1天...     

湖北省出口蛋品重金属和农药、兽药残监测及安全评价

为全面评估湖北省出口蛋品重金属和农兽残污染状况,采集了湖北省出口蛋禽备案养殖场的原料蛋及蛋制品,测定重金属汞、铅、砷、镉和农药六六六、滴滴涕等,兽药氯霉素、硝基呋喃类(呋喃唑酮、呋喃它酮、呋喃西林、呋喃妥因)、四环素类(四环素、土霉素、金霉素)、氟喹诺酮类(环丙沙星、恩诺沙星)、抗球虫药(盐霉素),非法添加物(三聚氰胺、苏丹红),环境污染物多氯联苯等含量和致病菌污染。依据国家标准对监测结果进行判定,鲜蛋样品中有5个样品检出重金属砷、铅、汞,皮蛋和咸蛋样品重金属铅、汞均有检出,砷有部分检出,所有检出样品质量均符合国家标准;兽药残留检测中有2个样品检测出氟喹诺酮类药物(1个样品环丙沙星含量6.5μg/kg,恩诺沙星140.0μg/kg;另1个样品环丙沙星含量14.8μg/kg,恩诺沙星162.7μg/kg),其他农药残留、非法添加物和微生物污染等监测项目全部合格。表明湖北出口蛋品总体质量水平高,食用安全,但也应关注蛋品中存在的重金属和兽药污染潜在威胁。     

不同光照桑叶养蚕时添食蔗糖对蚕茧和蚕种的影响

用搭棚遮荫的方法人为造成日照不足的桑叶，以研究养蚕时在光照叶和遮荫叶上添食蔗糖的效果。结果表明光照叶或遮荫叶上添食蔗糖，对蚕茧和蚕种的产质量均无影响。