措施切实可行综合防治蚕病--蚕业生产中综合防治蚕病发生的经验总结

常言道:"养蚕要高产,防病第一关".在农村养蚕中,蚕病的发生是影响蚕产茧质量的主要因素.要做到无病夺高产,必须坚持"预防为主、综合防治"的方针,把消毒防病工作贯穿于养蚕全过程.本人根据长期在基层接触的一些实际情况及体会,现将蚕病综合防治的主要措施归纳如下,谨供大家参考.     

兰溪农村蚕病发生情况及防治对策

在养蚕过程中,影响优质、高产、高效的因素很多,如要求蚕儿吃得饱、吃得好、住得好,以及避免发生农药中毒或蚕病等等.其中蚕病发生是我市近年来影响蚕茧产、质量的主要因素.只有在无病的基础上,才能谈到提高茧质和增加效益.有的农民反映:这几年蚕儿越来越难养了,真是"想养蚕,怕养蚕,特别怕养夏秋蚕","蚕病多,单产低,收入少".长此下去,势必影响蚕农积极性,阻碍蚕桑生产发展.笔者根据我市农村蚕病发生情况,提出     

养蚕生产中蚕病发生的原因及应对措施

本文阐述了养蚕生产中蚕病发生及危害的特点,分析了老蚕区养蚕中蚕病发生的原因,提出了加强蚕病防治、提高农村养蚕经济效益的措施。     

简易活动蚕台应用技术研究与推广

<正> 简易活动蚕台,是目前农村省力化养蚕的重要形式之一。我县蚕台应用存在制作技术及养蚕操作技术不科学、不规范,以致出现蚕儿发育不齐,蚕病损失超过蚕箔育,影响了蚕台多功能优势的充分发挥。为此,主要研究蚕儿上台最佳时期、最宜数量、上蔟技术     

农村蚕病防治中的存在问题及对策

<正>当前农村的养蚕方式,除小蚕期部分蚕农进行联户共育外,大蚕期及绝大部分养蚕户的小蚕期都是分户饲养方式,由于千家万户分户饲养,其技术水平、养蚕条件、消毒防病等工作水平不一,给技术指导和防病技术推广带来一定难度,致使农村蚕区蚕病病原普遍扩散,特别是近年来,蚕病危害逐年加重,夏秋蚕期经常暴发脓病及僵病,2003年中秋蚕睢宁县大面积暴发蝇蛆病,     

象州县蚕病发生的原因及防治意见

阐述了象州县农村养蚕过程中蚕病发生及危害的特点,分析了象州县农村养蚕中蚕病发生的原因,提出了加强蚕病防治、提高象州县种桑养蚕经济效益的防治措施。     

浅析近年蚕病危害态势及防治方略

近年来,由于种种原因淮阴区农村养蚕蚕病危害加剧.据不安全统计,因蚕病危害年平均损失占总产量的15%以上,蚕病重灾户颗粒无收,严重挫伤了蚕农生产积极性,对淮阴区蚕桑生产的稳定与发展构成了较大威胁.控制蚕病发生,减少蚕茧损失,已成为当务之急.     

创办“小蚕公司”初见成效

随着农村产业化结构的调整,越来越多的农民走出了土地的圈子,离土离乡进城务工经商,导致农村养蚕劳力老年化、妇女化、文化素质低下,蚕桑技术的接受能力较弱,小蚕饲养水平低,严重影响蚕桑生产效益.为提高小蚕饲养水平,适应农村形势发展,我乡在县茧丝绸公司的支持、帮助下,于2001年春蚕期在联欢、曹家创办了两家小蚕公司,公司以饲养小蚕、出售小蚕解决农村养蚕实际问题为目的,进行小蚕专业化饲养,打破传统的养蚕方法,推行十天养蚕法,在饲养模式上进行一项改革.现将有关饲养情况通报如下.     

农村养蚕生产中几种常见蚕病的区别及防治

蚕病是养蚕生产的大敌 ,无论什么季节 ,什么条件下养蚕 ,都有不同程度蚕病的发生和危害。在农村中 ,蚕农由于缺乏蚕病方面的知识 ,家蚕得病后对几种常见蚕病又不能正确及时识别 ,致使蚕病得不到及时科学有效的控制 ,最终影响蚕茧产质量 ,给蚕农带来了很大的经济损失。针对农村这一现状 ,笔者认为 :对广大蚕农普及几种常见蚕病的识别与防治知识是非常必要的。1　蚕病的种类蚕病的种类可分为传染性蚕病和非传染性蚕病。传染性蚕病包括病毒病、细菌病、真菌病和原虫病四大类 ,它是由病原微生物侵入蚕体并在体内增殖而引起的病害 ,又可以通过病…     

当前农村蚕病防治中的存在问题及对策

<正> 当前农村的养蚕方式,除小蚕期部分联户或集体共育外,大蚕期及绝大部分养蚕户的小蚕期都是分户饲养方式,由于千家万户分户饲养,其技术水平、养蚕条件、消毒防病等工作水平不一,给技术指导和防病技术推广带来一定难度,致使农村蚕区蚕病病原普遍扩散,特别是近年来,蚕病危害逐年加     

Salmonella in pork cuttings in supermarkets and butchers' shops in Denmark in 2002 and 2006

The prevalence of Salmonella in fresh pork cuttings in Denmark in the years 2002 and 2006 was investigated at retail and compared with the retail supply pattern. A total of 1025 and 3473 samples were taken in 2002 from butcher's shops and supermarkets, respectively. The corresponding numbers in 2006 were 259 from butchers' shops and 628 from supermarkets. In 2002, 1.2% of all samples were positive for Salmonella; butchers' shops and supermarkets had 1.8% and 1.0% positive samples, respectively. The overall prevalence in 2006 was 4.2%, with prevalence of 8.1% and 2.6% for butchers' shops and supermarkets, respectively. Hence, increases around 3- to 5-fold were found. There was neither observed any parallel increase in Salmonella positive carcasses in Danish slaughterhouses during the study period, nor were any changes in supply routes towards slaughterhouses with higher prevalence observed, which could explain the apparent increase. We hypothesize that hygiene levels and ability to avoid cross-contamination and prevent growth of the organism, in the meat processing chain after slaughter were the most likely responsible factors. Results from this study indicate that the hygiene performance, particularly at retail, has a significant impact on the occurrence of Salmonella. This implies that there is no direct link between slaughterhouse Salmonella surveillance data and the level of Salmonella contamination at retail. To improve risk assessment of Salmonella in fresh pork meat, this study underlines the need for comprehensive retail data.     

Helminth and protozoan parasites in dogs and cats in Belgium

This study investigates the level of helminthic and protozoal infestation over the last 10 years in strays, well-cared-for dogs and cats. Determination of the prevalence of infections was based either on faecal examination or on worm counts at necropsy. Of 2324 faecal flotations (NaCl sp.gr. 1.20) of stray dogs, 34.2% had eggs or proglottids of one or more worm species consisting of Toxocara canis (17.4%), Toxascaris leonina (10.1%), Uncinaria stenocephala (11.4%), Trichuris vulpis (7.0%) and cestodes (2.1%). Isospora oocysts were observed in 5.2% of the dogs. The data on the distribution of the various worm species in the positive dogs indicate that T. canis eggs were by far the most common (50.9%). Necropsy data from 212 infected dogs indicate that 38.9% were infected with T. canis and 33.7% with T. leonina. The overall prevalence of worm infestation of 246 well-cared-for kennel dogs, based on worm egg counts by the McMaster technique, was 36.1%. Of 30 feline faecal samples examined by flotation, 83.3% were positive for parasites, including Toxocara cati (60%), Ancylostoma tubaeformae (36.6%), Taenia (Hydatigera) taeniaeformis (20%) and coccidia (30%). Toxocara cati was the most frequently found worm species at the necropsy of 25 cats (52%). Toxoplasma was not observed.     

Sanguinarine metabolism and pharmacokinetics study in vitro and in vivo

Sanguinarine (SA) is a benzo[c] phenanthridine alkaloid which has a variety of pharmacological properties. However, very little was known about the pharmacokinetics of SA and its metabolite dihydrosanguinarine (DHSA) in pigs. The purpose of this work was to study the intestinal metabolism of SA in vitro and in vivo. Reductive metabolite DHSA was detected during incubation of SA with intestinal mucosa microsomes, cytosol, and gut flora. After oral (p.o.) administration of SA, the result showed SA might be reduced to DHSA in pig intestine. After i.m. administration, SA and DHSA rapidly increased to reach their peak concentrations (C_max, 30.16 ± 5.85, 5.61 ± 0.73 ng/ml, respectively) at 0.25 hr. Both compounds were completely eliminated from the plasma after 24 hr. After single oral administration, SA and DHSA rapidly increased to reach their C_max (3.41 ± 0.36, 2.41 ± 0.24 ng/ml, respectively) at 2.75 ± 0.27 hr. The half-life (T_1/2) values were 2.33 ± 0.11 hr and 2.20 ± 0.12 hr for SA and DHSA, respectively. After multiple oral administration, the average steady-state concentrations (C_ss) of SA and DHSA were 3.03 ± 0.39 and 1.42 ± 0.20 ng/ml. The accumulation indexes for SA and DHSA were 1.21 and 1.11. The work reported here provides important information on the metabolism sites and pharmacokinetic character of SA. It explains the reasons for low toxicity of SA, which is useful for the evaluation of its performance.     

Chlortetracycline in swine-bioavailability and pharmacokinetics in fasted and fed pigs

Chlortetracycline hydrochloride was administered intra-arterially (11 mg/kg) and as an oral drench (33 mg/kg) to ten 21.0-31.5-kg pigs. Five of the pigs were fasted 18 h prior to dosing and five of the pigs were fed ad libitum prior to dosing. The mean volume of distribution determined by area-under-the-curve calculations for the fasted pigs (0.967 +/- 0.210 l/kg) was significantly less (P less than 0.05) than the mean volume of distribution for the fed pigs (1.39 +/- 0.31 l/kg). Mean total body clearance of the drug was also significantly less (P less than 0.05) in the fasted pigs (0.165 +/- 0.055 l/kg/h) as compared to the fed pigs (0.307 +/- 0.053 l/kg/h). The elimination constants (beta) were not found to be statistically different (P less than 0.05): 0.1811 +/- 0.0057 for the fasted pigs; 0.2260 +/- 0.0461 for the fed pigs. The bioavailability for both groups was similar; 19.12 +/- 8.3% for the fasted pigs and 17.88 +/- 5.3% for the fed pigs. In a second experiment three groups of six pigs which weighed 34.5-44.1 kg were fed a corn-soy diet ad libitum. The rations were fortified with chlortetracycline at 100, 400 or 1000 mg chlortetracycline hydrochloride/kg feed. Chlortetracycline concentrations were determined in plasma samples collected over a 6-day period. Plasma chlortetracycline concentrations reach a plateau within 24 h after initial access to the trial diets and were highly correlated with the dose of the drug consumed (r2 = 0.97).     

2005年国内蛋、肉鸡市场分析回顾及2006年走势预测

2005年如果没有年底的禽流感疫情,对于我国蛋鸡、肉鸡生产来说应该是一个非常完美的丰收年,是哪些因素导致了2005年蛋鸡市场如此好的行情?2006年我国家禽市场又将走向何方?……作者对以上热点问题进行了深入分析研究,供读者参考。     

Pharmacokinetics of penicillin-G in ewes and cows in late pregnancy and in early lactation

Concentrations of penicillin-G in serum were determined after single intravenous doses of potassium penicillin-G (10 mg/kg body wt) to ewes and cows in late pregnancy and in early lactation. Penicillin-G in serum was analysed by a microbiological method and pharmacokinetic parameters were calculated by model-independent methods. Serum concentrations were lower in early lactation than in late pregnancy in both ewes and cows. The differences were statistically significant at most sampling times in ewes but only during the first hour in cows.
Weight corrected values of clearance and volume of distribution were significantly higher in early lactation than in late pregnancy in both ewes and cows. Mean residence time and elimination-half life were shorter in lactating than in pregnant ewes, however for the latter parameter the difference was not statistically significant. Neither of these parameters changed in cows.
It is concluded that in both ewes and cows pharmacokinetic parameters of penicillin-G are altered from late pregnancy to early lactation but that these changes have little practical impact and do not call for a revised dosage regime of the studied drug.     

Mycobiota and aflatoxins in raw materials and pet food in Brazil

Commercial feedstuffs are a basic element in modern pet husbandry in the world. In dogs, the effect of mycotoxins is severe and can lead to death. Few reports on the influence of dietary mycotoxins were found in the scientific literature. The aims of this work were to isolate and identify the mycoflora and to determine the aflatoxins (AFs) natural occurrence in raw materials and ready dry pet food. Therefore, the aflatoxigenic capacity of Aspergillus flavus species was investigated. Aspergillus was the prevalent genera (65-89%) followed by Penicillium and Fusarium spp. Aspergillus flavus was the most prevalent species, followed by Aspergillus sydowii, Aspergillus fumigatus and Aspergillus versicolor. Aspergillus flavus frequencies ranged from 58% to 86% except in sorghum meal. All samples assayed (except corn grains and ready pet food) showed Fusarium spp. contamination. Corn meal and corn meal and gluten samples had 100% Fusarium verticillioides. Fusarium graminearum was isolated from sorghum meal. Aspergillus flavus strains (75%) isolated from raw materials and 57% from pet food were able to produce AFs. All samples showed AFs contamination percentages over 70%; corn and sorghum meal obtained the highest AFs levels. Ready pet food did not show quantitative levels of the tested toxins. This is the first report of the aflatoxigenic capacity by A. flavus from Brazilian pet food.