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1.
<正>前人的研究报导,家蚕对蚕微粒子(N.bombycis)抵抗力因蚕品种、蚕的发育时期、饲育条件等不同而有差异。中系品种抵抗力强,欧系品种弱,日系品种介乎二者之间;多  相似文献   

2.
六、蚕品种的抵抗性蚕儿对于病毒性软化病的抵抗力虽受各种饲育环境因素的影响,但形成耐病性的基本东西是由蚕品种或品系所具有的遗传的抵抗性所形成的。很早就认为对病毒性软化病的抵抗力因蚕品种而有显著的不同。一般来说,属于日本种的蚕品种对 FV有感受性,相反中国系统的很多蚕品种有抵抗性。杂交种F_1的抵抗力一般比两亲原种强,表现杂种优势,特别是两个感受性品种  相似文献   

3.
<正>肉鸡传染性法氏囊病是由鸡传染性法氏囊病毒引起鸡的一种高度接触性传染病。法氏囊病毒在环境中抵抗力强,耐酸、耐热,对胰蛋白酶、氯仿、乙醚溶剂均有抵抗力。一般的消毒剂对其消毒  相似文献   

4.
1选择优质的蛋鸡品种不同的蛋鸡品种生产性能不同,对疾病的抵抗力和对气候、饲料的要求也不同。养殖户在购买鸡苗时,一定要到正规的大型种鸡场,根据当地的实际情况选择抗病力强、饲料消耗适中的纯正蛋鸡品种,千万不要贪图一时的便宜,购买来路不明品种不纯的鸡苗。2养好后备鸡群要使产蛋高峰期长久持续、产蛋率居高不下,必须把蛋鸡的各项生理功能调整到最佳状态。  相似文献   

5.
从蚕作安定的观点来看,主要的蚕病是软化病(F),脓病(N),中肠型多角体病(C)和硬化病(M)等,特别是前三者,至今尚未解决的问题还很多。关于上述这些重要蚕病的防除,作者现把自己和同事们的研究结果,记述如下。第一、是选育对于上述蚕病抵抗性强的品种。从我们的研究成果来看,对上述蚕病的抵抗性是因蚕品种而异,并且有显著抵抗力强的品种,由此可见抵抗性强的品种的育成是可能的。在那些耐病性品种内,  相似文献   

6.
东北民猪是我国优良的地方猪种之一,具有耐粗饲、抗病力强和产仔率高等特点。郑坚伟(1985)报道民猪的肌肉和骨重对限制营养的抵抗力强于哈白猪,补偿力则不如哈白猪。然而,有关民猪和哈白猪骨骼外侧面积对限制营养的抵抗力和补偿力尚未见报道。本试验观察了在采用维持和低维持饲养时,民猪与哈白猪骨骼外侧面积发生的变化,探讨了两个品种对限制营养的抵抗力和补偿力,为揭示民猪的种质特性,改  相似文献   

7.
正鸡白痢是由属于D血清群的鸡白痢沙门氏菌引起的一种细菌性传染病。近年来发现各种日龄的鸡均会感染发病。不同品种的鸡对鸡白痢沙门氏菌具有不同的遗传抵抗力,如体温高、基础代谢强的来航鸡就比洛岛红鸡抵抗力强,在鹌鹑和珍珠鸡中也有暴发本病的报道。本病一年四季均可发生,尤以冬春出雏季节多见。该病世界范围内都有发生,造成严重的经济损失。本文通过几种抗菌药物的抑菌试验,探讨抗菌药物对鸡白痢的治疗效果。  相似文献   

8.
一、病原与临床症状 鸡痘是由鸡痘病毒引起的一种急性、热性、高度接触性禽类传染病。任何年龄、性别和品种的鸡易感性都很高。鸡痘病毒是一种比较大的病毒,为痘病毒群、禽痘毒亚群的一种。鸡痘病毒对干燥的抵抗力相当强,在上皮细胞屑中的病毒,虽经完全干燥并经阳光照射数周,还能保持活力:鸡痘病毒对常用的消毒药抵抗力较弱,1%烧碱、1%醋酸、  相似文献   

9.
广东地处亚热带,冬季短,夏季长,雨量充沛,形成了全年多次采叶养蚕的特点,其蚕品种资源经过长期的自然变异、淘汰以及人工选择,出现了许多性状迥异、各具特色的丰富多姿的地方品种资源。这些地方品种大都能适应高温多湿的气候环境,具有耐高温多湿,抗病力及抗逆性强,强健好养,龄期经过短,对桑叶饲料要求不严,对我国蚕区经常发生、流行的主要蚕病、大气污染等有较强的抵抗力。为此,我所在家蚕品种资源的保存与创新利用方面做了大量的研究工作,选育  相似文献   

10.
该病发生后,病羊常伴发并发症,如呼吸道炎症、肺炎、关节炎、胃肠炎等,幼龄羔羊死亡率很高,还可引起孕羊流产等。(一)发病特点不同品种和年龄的绵羊易感性不同,外来品种的羊易感性强,粗毛羊或当地品种羊则有一定的抵抗力。该病可全年发生,但以冬春两季较多。引进处于潜伏期或体表带毒的羊只;购入被痘病毒污染的羊  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
14.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

15.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

16.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

17.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

18.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

19.
The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.  相似文献   

20.
<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.  相似文献   

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