共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
柑桔衰退病(CTV)是世界柑桔生产中最严重的病害之一。至今,该病仍是世界各国以酸橙作砧木的柑桔产区的一个严重威胁。近年,随着我国柑桔品种结构调整,CTV在某些品种上有日益严重的趋势。因此,快速准确地诊断、鉴定该病成为当前柑桔生产中的迫切需要,以便采取适当措施防止此病蔓延危害。笔者查阅了大量国内外文献,并总结科研生产中的经验,特提出CTV综合诊断技术,为诊断、防治该病害提供参考。1背景辅助诊断 CTV广泛分布于世界各柑桔产区,现已有50多个国家或地区报道发生此病。据Bar-Joseph等推测,CT… 相似文献
3.
4.
5.
摘 要:柑橘大实蝇是我国柑橘产区主要虫害之一,使柑橘生产损失巨大。由于其卵、幼虫、蛹具有隐蔽为害的特点,成虫期的诱杀防控成为该虫预测预报和防治的重要手段之一,应用广泛。本文从诱杀剂筛选(食物引诱剂、信息素引诱剂和杀虫剂)和诱杀方式(诱器法和点喷法)两个方面综述了国内外最新研究成果,旨在为柑橘大实蝇诱杀剂筛选、诱杀方式改进以及成虫预测预报和防治方面提供理论参考。 相似文献
6.
介绍了鸡传染性法氏囊痛(IBD)的病原特征、流行病学特点、临床症状、病理剖检变化及实验室诊断方法,提出预防和控制该病的有效途径及防治体会,为养鸡生产提供一定的参考。 相似文献
7.
近年来规模化猪场经常出现以散发突然死亡为特征的疾病(猝死症)。该病(症)主要发生在母猪,尤其是怀孕1~2个月的经产母猪。体况良好的母猪发病率高,给猪场带来不小损失。笔者现将该病的特点、原因及防治介绍如下。 相似文献
8.
9.
10.
11.
12.
13.
Borrelli L Fioretti A Ruggiero V Santaniello A Cringoli G Ricci A Barco L Menna LF Dipineto L 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(3):385-387
A total of 1,000 rectal samples were collected from rabbits coming from 25 rabbit farms in southern Italy. All samples were processed for isolation of Salmonella spp. by standard culture method based on the ISO 6579:2002 method. Salmonella spp. was isolated from 1/25 rabbit farms analyzed. In particular, four out of 1,000 rectal swab samples, taken from young rabbits, were serotyped as S. Typhimurium and phage typed as S. Typhimurium DT104. All the isolates were resistant to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (ACSSuT pentaresistance type). The findings of the present study suggest the rabbit as potential carrier of S. Typhimurium DT104. 相似文献
14.
AIM: To estimate over a 3-year period following the first release of rabbit haemorrhagic disease virus (RHDV) the prevalence of rabbit haemorrhagic disease (RHD) and the abundance of rabbits (Oryctolagus cuniculus) in an area that historically had low rabbit densities. METHODS: Three farms grazing predominantly sheep and beef cattle, located close together and with low initial rabbit densities, were selected for study. RHDV had been deliberately released on all farms in December 1997. Farms were visited 2-3 times per year between June 1998 and April 2001. At each visit, rabbits were shot with the aid of spotlights at night and blood samples were collected for detection of RHDV antibodies. Rabbit carcasses were necropsied and the age of the animals was determined. Rabbit abundance on each property was measured throughout the study using spotlight night counts. Logistic regression was used to identify factors associated with the risk of carcasses being seropositive for RHDV. RESULTS: Rabbit density differed initially between farms (8.2, 9.9, 2.3 rabbits per spotlight km in June 1998), and declined on all three properties over time (1.2, 2.4, 1.1 rabbits per spotlight km in November 2000). Highest antibody titres to RHDV were initially evident on the farm on which rabbits were most abundant. The average prevalence of seropositive rabbits overall was 21% (95% CI=15-28%). Female rabbits tended to be less likely to be seropositive for RHDV than males (OR=0.47; 95% CI=0.21-1.02). The odds of becoming seropositive were reduced for rabbits born in the breeding season of 1999-2000 (OR=0.17; 95% CI=0.05-0.64). CONCLUSIONS: The temporal pattern of outbreaks measured by peaks of seroprevalence differed between closely-spaced farms when they had different rabbit densities, but were similar when rabbit densities were similar. Microclimate and vegetation influencing abundance of insect vectors for RHDV and intrinsic population-related factors like rabbit breeding behaviour are also likely to be involved in local patterns of spread. 相似文献
15.
AIM: To estimate over a 3-year period following the first release of rabbit haemorrhagic disease virus (RHDV) the prevalence of rabbit haemorrhagic disease (RHD) and the abundance of rabbits (Oryctolagus cuniculus) in an area that historically had low rabbit densities. METHODS: Three farms grazing predominantly sheep and beef cattle, located close together and with low initial rabbit densities, were selected for study. RHDV had been deliberately released on all farms in December 1997. Farms were visited 2–3 times per year between June 1998 and April 2001. At each visit, rabbits were shot with the aid of spotlights at night and blood samples were collected for detection of RHDV antibodies. Rabbit carcasses were necropsied and the age of the animals was determined. Rabbit abundance on each property was measured throughout the study using spotlight night counts. Logistic regression was used to identify factors associated with the risk of carcasses being seropositive for RHDV. RESULTS: Rabbit density differed initially between farms (8.2, 9.9, 2.3 rabbits per spotlight km in June 1998), and declined on all three properties over time (1.2, 2.4, 1.1 rabbits per spotlight km in November 2000). Highest antibody titres to RHDV were initially evident on the farm on which rabbits were most abundant. The average prevalence of seropositive rabbits overall was 21% (95% CI=15–28%). Female rabbits tended to be less likely to be seropositive for RHDV than males (OR=0.47; 95% CI=0.21–1.02). The odds of becoming seropositive were reduced for rabbits born in the breeding season of 1999–2000 (OR=0.17; 95% CI=0.05–0.64). CONCLUSIONS: The temporal pattern of outbreaks measured by peaks of seroprevalence differed between closely-spaced farms when they had different rabbit densities, but were similar when rabbit densities were similar. Microclimate and vegetation influencing abundance of insect vectors for RHDV and intrinsic population-related factors like rabbit breeding behaviour are also likely to be involved in local patterns of spread. 相似文献
16.
17.
不同规模工厂化养猪的成本及效率分析 总被引:1,自引:0,他引:1
我国生猪养殖规模和水平参差不齐,本文以26家规模化猪场为研究对象,其中包括规模Ⅰ(2000头以下基础母猪)3家、规模Ⅱ(2000~3000头基础母猪)3家、规模Ⅲ(3000~4000头基础母猪)4家、规模Ⅳ(4000头以上基础母猪)16家,比较不同养殖规模工厂化养猪场的生产成本和生产效率。结果表明:不同规模的工业化猪场在生产成本与生产效率方面有显著差异。随着规模增加,生长育肥期饲料成本、兽药疫苗、固定资产折旧及人工费用降低,生长育肥阶段成本明显下降,出栏猪成本与规模呈现负相关。仔猪哺乳及仔猪保育阶段对管理水平要求较高,随着养殖规模增大,管理难度相应加大,需要强调实施精细管理,以维持平均每头基础母猪年提供断奶仔猪头数(PSY)以及平均每头基础母猪年提供出栏猪头数(MSY),达到最大限度的规模效益。 相似文献
18.
Blanc V Mesa R Saco M Lavilla S Prats G Miró E Navarro F Cortés P Llagostera M 《Veterinary microbiology》2006,118(3-4):299-304
This study aims to determine the presence of extended-spectrum (ESBL) and plasmidic class C beta-lactamase-producing Enterobacteriaceae in poultry, pig and rabbit farms of Catalonia (Spain). PFGE typing showed a low clonal relationship among strains carrying these mechanisms of resistance. Ninety-three percent of them were resistant to two or more of the non-beta-lactam antimicrobials tested and harboured ESBL and plasmidic class C beta-lactamases. Greater diversity of these enzymes was found in strains from poultry farms, the CTX-M-9 family, especially CTX-M-14, with CMY-2 being the most frequent. The isolation of TEM-52 and SHV-2-producing Escherichia coli strains from these animal farms is noteworthy. In contrast, 73% of the strains from pig farms had CTX-M-1, and neither the CMY-type nor CTX-M-9 family enzyme was found. Likewise, it is the first time that CTX-M-1 and SHV-5 encoding strains have been isolated in pigs. On the other hand, in rabbit farms CTX-M-9 family was also the most frequent, being detected in three of a total of four strains. The last one showed a CMY-2, for the first time detected in these animals, too. In conclusion, commensal E. coli strains of food-producing animal farms are a reservoir of ESBL and plasmidic class C beta-lactamases. 相似文献
19.
The associations between milk production, milk composition and Salmonella in the bulk milk supplies of dairy farms in Ontario. 下载免费PDF全文
The purpose of this study was to assess changes in dairy herd milk production and milk composition associated with changes in Salmonella contamination of bulk milk on dairy farms in southwestern Ontario. Twenty-three dairy farms that had submitted milk filters for culture from which Salmonella were isolated (cases) and 23 farms that submitted Salmonella-negative milk filters (controls) were included in the study. The rolling herd averages for milk and fat of case and control farms for the months of December 1985, December 1986 and April 1987 were compared and no significant differences were detected. Case and control farms were divided into three groups (A,B,C) on the basis of Salmonella culture results of milk filters submitted at various time periods throughout the study. Daily and monthly changes in milk production and composition parameters that reflected the time periods of milk filter culture were compared. The following unconditional associations between a changing Salmonella infection status on dairy farms and changes in milk production or composition variables were significant (p less than or equal to 0.05): group A: case farms had higher plate loop counts than control farms; group B: case farms had younger cows than control farms; group C: case farms had cows with longer average days in lactation than control farms. After analytical control of confounding variables, the disappearance of Salmonella from bulk milk supplies of dairy farms was associated with a decrease in percent fat and in somatic cell count. 相似文献
20.
蚕种场是蚕种生产与经营的微观主体。通过对全国136家蚕种场问卷调查数据的统计分析,认为我国蚕种场普遍存在以下问题:生产设施陈旧,基础条件落后;人员负担沉重,科技力量薄弱;生产经营规模小,产能过剩严重;蚕种销售范围狭窄,区域分割依旧;科技创新能力不足,缺乏多元化拓展的技术支撑;等等。这些问题导致我国蚕种场整体劳动生产率和资产利用率较低,经济效益较差,除广西、广东和云南3省(区)外,其它省份的蚕种场基本处于亏损状态。从所有制结构来看,虽然各类所有制蚕种场总体都是亏损的,但私营蚕种场的亏损相对最小。建议通过深化蚕种场体制改革,放松对蚕种价格与流通的管制,实现规模化蚕种生产经营,推进科技创新步伐,拓展多元化发展渠道以及发挥政府扶持作用等途径,努力提高我国蚕种场的生产经营效益。 相似文献