白僵菌防治松毛虫研究和技术推广

白僵菌防治松毛虫研究以及二十二年来在省内66个县撒放900t白僵菌粉,防治142万余亩松林松毛虫,实践证明应用白僵菌防治马尾松毛虫不会影响养蚕业,不会增加家蚕的僵病数量,这主要是由于防治松毛虫用的是松毛虫白僵菌,它对家蚕致病力低,对松毛虫致病力高,菌株不同;放菌治虫后,白僵菌数量很快消退到原来自然界的水平;松毛虫白僵菌在自然界的数量达不到使家蚕致病的数量。白僵菌的生产解决了三大技术难点:产品干燥技术,机械分离白僵菌孢子技术和高孢粉生产技术。解决了白僵菌的生产问题。明确了使用方法:纱布袋撒粉、机械喷粉和飞机喷洒;确定了放菌量,常规菌粉0.5～1.0kg/亩,高孢粉1.0～10.0g/亩;明确了放菌时间,每年10～11月份,3～4月份防治越冬代松毛虫;浙南、浙东南、沿海县市是我省最适合应用白僵菌防治松毛虫的地区,白僵菌的防治效果在70%以上。解决了白僵菌的使用问题。全省已广泛应用白僵菌防治松毛虫,有些地区白僵菌防治面积占总防治面积的1/3,已成为我省防治松毛虫的主要手段。应用白僵菌防治松毛虫挽回损失折合人民币3184.09方元,有显著的经济效益。     

石羊河流域春秋不同播期人工牧草气候生产力分析

2003～2005年对石羊河流域春秋两种播期人工牧草紫花苜蓿(Medicago sative)、沙打旺(Astragalus adsurgens)的生育期,地上、地下生物量,产量等进行了连续测定。结果表明:(1)紫花苜蓿、沙打旺生长第二年(2004年)干物重春播地均高于秋播地。分别增产3 505.0 kg/hm2、2 314.5 kg/hm2。(2)春播和秋播地牧草干物质积累增长关键期均出现在现蕾～开花期。此期紫花苜蓿、沙打旺干物质积累量分别占累积总量的70%和63%。(3)生长第二年(2004年)春播和秋播地青干比最小值出现在开花期,也是牧草刈割的最佳期。(4)春播牧草地下生物量高于秋播。春播紫花苜蓿、沙打旺根干重分别比秋播高2.5～2.6倍和0.5～1.0倍,春播有利于牧草根系生长。(5)春季日平均气温稳定通过5℃为牧草适宜返青温度。在灌溉条件下,牧草干重与热量因子呈显著正相关,生产力高低主要取决于热量的多寡,秋播地和晚熟品种对热量条件的需求更高。     

0～3周龄肉仔鸡日粮中维生素E的适宜供给量研究

为了探讨０～３周龄肉仔鸡日粮中维生素Ｅ的适宜供给量,将一日龄艾维茵肉仔鸡９００只分成５个处理组,每组含６个供测定生产性能用的重复小组（各小组２２只,公母各半）和１个含公雏鸡４５只的小组,以便采血、屠宰取器官供测定α生育酚和硫巴比妥酸反应物质（ＴＢＡＲＳ）。各组的基础日粮相同,含α生育酚１３ｍｇ／ｋｇ,各组日粮中分别添加ｄｌα生育酚醋酸酯０、５、１０、５０和１００ｍｇ／ｋｇ。试验结果表明,０～３周龄肉仔鸡的玉米豆粕豆油型日粮中不同维生素Ｅ水平不明显影响采食量;维生素Ｅ含量达到１８～２３ｍｇ／ｋｇ以上才能维持肉仔鸡正常的快速生长及１１～２１日龄阶段血浆恒定的α生育酚含量,当日粮中只含维生素Ｅ１３ｍｇ／ｋｇ时,血浆和肝脏中α生育酚明显随鸡日龄增大而耗竭（Ｐ＜００５）。日粮中维生素Ｅ含量达到１１３ｍｇ／ｋｇ时,肉仔鸡肝脏组织的α生育酚含量在各日龄点明显最高（Ｐ＜００５）且较恒定,ＴＢＡＲＳ值在１１、１６及２１日龄时最低且与含维生素Ｅ１３ｍｇ／ｋｇ和１８ｍｇ／ｋｇ组的差异显著,说明抗氧化能力最强。     

水稻不同矮生基因品种对赤霉素反应的研究

在水稻苗期和园秆拔节期，用不同浓度的赤霉素（ＧＡ３）溶液，处理ｓｄ－１和４个非ｓｄ－１基因矮生和半矮生水稻品种，结果表明，４个矮生和半矮生品种株高对赤霉素反应和ｓｄ－１基因品种一样，都为敏感。其中只有ｓｄ－ｓ（ｔ）基因的雪河矮早，苗期在低浓度（１０ｐｐｍ）条件下不敏感，浓度≥２０ｐｐｍ条件下表现敏感。成株期在１００ｐｐｍ浓度下，有的年份敏感，有的年份不敏感。说明目前国内外采用以水稻株高对赤霉素反应     

Effects of Bacillus amylolyticus on Rumen Dry Matter Digestibility,Fermentation Parameters and Metabolites of Dairy Cows北大核心CSCD

This experiment was conducted to study the effects of Bacillus amylolyticus on rumen dry matter digestibility, fermentation parameters and metabolites of dairy cows. Experiment 1: six dairy cows with permanent fistula and had the similar parity (2 to 3 fetuses), body weight [(662 ±57) kg], lactation days [(160 ± 22) d] and milk yield [(36.1 ±3.8) kg / d], were randomly divided into 3 groups with 2 cows per group. Using 3 ×3 Latin square design, each group was extra fed 0 (control group), 5 ×109 and 5 ×1010 CFU / d Bacillus amylolyticus, the trial period was 3 periods, 13 days for each period, including 10 days for the pre-trial period and 3 days for the trial period. At the beginning of the trial period, the rumen dry matter digestibility of cows was measured by nylon bag method. Experiment 2: thirty dairy cows with similar parity [(2.5 ±0.3) fetuses], initial body weight [(559.2 ± 7. 4) kg], milk yield [(35. 2 ± 1. 5) kg / d] and lactation days [(99 ± 22) d] were randomly divided into three groups with 10 cows in each group. Cows in the 3 groups were extra fed with 0 (control group), 5 ×109 and 5 ×1010 CFU / d Bacillus amylolyticus, respectively. The pre-trial period was 10 days and the trial period was 42 days. The rumen fluid was collected on the last day of the trial period, and the rumen fermentation parameters and metabolites were determined. The results showed as follows: compared with the control group, 1) supplementary feeding of 5 × 1010 CFU / d Bacillus amylolyticus could significantly improve the rumen dry matter digestibility of dairy cows at 12, 24, 36, 48 and 72 h (P <0.05), supplementary feeding of 5 ×109 CFU / d Bacillus amylolyticus could significantly improve the rumen dry matter digestibility of dairy cows at 36 and 48 h (P <0.05); 2) supplementary feeding of 5 ×109 CFU / d Bacillus amylolyticus could significantly increase the contents of isobutyric acid, butyric acid, isovaleric acid, valeric acid, total volatile fatty acid and microbial protein in the rumen of dairy cows (P < 0. 05), supplementary feeding of 5 × 1010 CFU / d Bacillus amylolyticus could significantly increase the contents of isobutyric acid and isovaleric acid in the rumen of dairy cows and significantly reduce the rumen acetic acid / propionic acid (P < 0. 05), supplementary feeding of 5 ×109 and 5 ×1010 Bacillus amylolyticus had no effects on rumen pH and ammonia nitrogen content (P >0.05); 3) eleven metabolic pathways related to differential metabolites were detected, and ascorbic acid and alginate metabolism were significantly enriched (P < 0. 05) . In conclusion, Bacillus amylolyticus can increase the rumen dry matter digestibility, and improve the rumen fermentation function of dairy cows by affecting the content of rumen metabolites. By comprehensive analysis, supplementary feeding of 5 × 109 CFU / d Bacillus amylolyticus can achieve better effect. © 2023 Authors. All rights reserved.     

业余定地养蜂的点滴体会

我业余养蜂12年,积累了一定的养蜂经验和教训.业余养蜂与专业养蜂不同.业余养蜂的困难较多,如受环境条件的限制,没有放蜂的场地,只能在休息时间看看蜂群,不能追花夺蜜,花期一过,全靠饲喂,等等.然而"世上无难事,只怕有心人".为了养好蜂,我利用早晚下班后的业余时间管     

拟穴青蟹Na+/H+ exchanger基因克隆及其在盐度胁迫下的表达分析

克隆了拟穴青蟹(Scylla paramamosain)Na~+/H~+-exchanger基因,其cDNA序列全长3 624 bp,开放阅读框(ORF)长2 886 bp,可编码961个氨基酸,预测蛋白质分子量和等电点分别为110.8 kDa和7.42,具有信号肽和典型的Na~+/H~+-exchanger蛋白结构域,含12个跨膜α螺旋。拟穴青蟹Na~+/H~+-exchanger的氨基酸序列与三疣梭子蟹(Portunus trituberculatus)的一致度最高,达到84.9%;该基因在卵巢中表达量最高,其次是精巢、鳃等;该基因在受精卵时期表达水平最高,大眼幼体时期次之。拟穴青蟹大眼幼体在低盐(盐度7和17)胁迫过程中,Na~+/H~+-exchanger基因在20 min表达水平最高,之后基本恢复到正常表达水平;在高盐(盐度37)胁迫(20 min～2 h)期间,该基因表达水平先下降再逐渐上升。Na~+/H~+-exchanger基因在拟穴青蟹大眼幼体阶段盐度适应中发挥着重要作用,且低盐显著诱导Na~+/H~+-exchanger基因的高表达,推测拟穴青蟹Na~+/H~+-exchanger基因在低盐环境下发挥重要的渗透调节功能。     

图书馆与人类社会文明的关系

图书馆是知识的殿堂,是文化保存和传播机构,对促进文化事业发展和推动社会文明进步做出了巨大贡献。在推动社会主义两个文明建设中,充分发挥图书馆的特性,强化社区两个文明建设,图书馆应从扩大图书馆网点,深化读者工作,加强科学管理,提高馆员素质等环节着手提高社会效益,弘扬人文精神。     

北牛南养重点防范牛焦虫病

牛焦虫病是由焦虫寄生在牛红细胞内引起的一种需硬蜱传播的血液原虫病。牛的焦虫病病原体种类繁多，异地调运常导致多种病原体同时寄生，引起混合感染，使病情加剧．2005年12月下旬贵州省县荔波县从北方引入高代杂交能繁母牛时就曾发生过牛的双芽巴贝斯焦虫和泰勒焦虫混合感染的病例。