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1.
松嫩平原榆树疏林植物组分的结构型   总被引:9,自引:1,他引:8  
李建东  杨允菲 《草地学报》2003,11(4):277-282,300
松嫩平原植被是蒙古、东北、兴安和华北4个植物区系成分相接触的区域,在全区所设的10个榆树疏林调查样地40个样方中,共有89种植物,隶属于26个科,6个株生长型,4个根生长型,6个生活型,4个水分生态类型,13个分布区型和6个饲用价值类型。其中,菊科种类最多,占22.5%;禾本科和豆科分别占15.7%和12.4%。株生长型结构以分枝型种类最多,占39%;直立型和丛生型分别为2l%和16%。根生长型结构以直根型的种类最多,占66%;根茎型和刷状根型分别为17%和16%。生活型结构以地面芽植物最多,占43%;地下芽植物和一年生植物次之,各占15%;地面-地下芽植物占12%。水分生态类型结构以中生型种类最多,占63%;中旱生型次之,占19%。分布区型结构以蒙古-东北-兴安-华北分布区型的种类最多,占30%;蒙古分布区型次之,占16%。饲用价值类型以中、低等质量的种类最多,占46%;优、良牧草种类占31%。松嫩平原榆树疏林具有典型的温带地面芽植物气候、中生生境条件、植物分布区型结构复杂、饲用价值较高的特征。  相似文献   

2.
矮小型褐壳蛋鸡解剖学研究   总被引:1,自引:0,他引:1  
通过对10只矮小型褐壳蛋鸡和10只正常型褐壳蛋鸡的解剖对比发现,矮小型的消化系统较发达,腺胃的相对重量比正常型鸡高17%,差异达到显著的水平(P<0.05),腺胃乳头的绝对数也大大高于正常型(74.1±10.4对54.4±9.5),多出36%(P<0.05%),肝脏、胰脏和肌胃的相对重量也略高于正常型,但差异不显著(P>0.05)。矮小型鸡的体重比正常型鸡低30%,背高低23%,身长短12%,肩宽窄10%,这些数据为今后矮小型鸡的鸡笼设计提供参考。矮小型鸡有较发达的胸肌,胸角角度比正常型鸡高18%,矮小型鸡的屠宰率也高于正常型鸡。  相似文献   

3.
松嫩平原羊草草甸植物的生态及分布区型结构分析   总被引:36,自引:13,他引:23  
松嫩平原羊草草甸穿越吉林省西部和黑龙江省西南部约129万hm^2的范围,是蒙古植物区系,东北植物区系,兴安植物区系,华北植物区系4个植物区系相汇集的区域,在全区所设的36个调查样地中,共有162个植物,隶属于36个科,6个株生长型,5个根生长型,6个生活型,5个水分生态类型,15个分布区型和6个经济价值类型。其中,菊科种类最多,占24.1%,豆科和禾本科分别占11.1%和10.5%;株生长型结构以分枝型种类最多,占31%,直立型和丛生型分别为22%和20%,根生长型结构以直根型的种类最多,占54%,刷状根型和根茎型分别为23%和19%;生活型结构以地面芽植物最多,占42%,地下芽植物次之,,占26%,地面-地下芽植物占9%,水分生态类型结构以中生型种类最多,占58%,中旱生型次之,占25%,分布区型结构以蒙古-东北-兴安-华北分布区型的种类最多,占26%,东北-华北分布区型次之,占17%,经济价值类型结构以中、低等质量的种类最多,所占比重高达50%,而优,良牧草种类只占22%,松嫩平原羊草草甸具有温带草本群落的植株和根系的特点,典型的温带地面芽植物气候特征,中生生境条件,复杂的分布区型结构和多样的经济价值类型。  相似文献   

4.
田间条件下,以3个莜麦(AvenanudaL.)品种(系)为母本同2个燕麦(A.sativaL.)品系配置双列杂交,研究裸粒性的遗传,结果表明,将莜麦型和中间类型计为一类(裸型)时,F2代有3裸型:1燕麦型和35裸型:29燕麦型两种分离比例。在3:1比例中,莜麦型和燕麦型均占20%~30%,而35:29中,燕麦型约占45%,莜麦型则在10%以下。两种比例中,中间型的比率相差不大,约为45%~55%。F1代主穗平均裸粒率与F2代裸型及莜麦型植株百分率间呈较高正相关,相关系数分别为0.817和0.917。  相似文献   

5.
副鸡嗜血杆菌分离鉴定血清学定型研究   总被引:1,自引:0,他引:1  
通过流行病学调查,发展我省有鸡传染性鼻炎流行,采集试验样品305份,分离得副鸡嗜血杆菌102株,分离率33.4%。根据Page的凝集试验分型方案,对102株副鸡嗜血杆菌分别与A,B,C三种标准血清定型,有64株菌定为A型占62.7%,其余38株为C型占37.3%。从流行地区的型别分布来看,有6个地区是A型和C型均有流行占37.5%,A型或C型单独流行的地区各有5个,各占31.25%。研究结果对研制  相似文献   

6.
鹅大肠杆菌病是由某些血清型的致病性大肠埃希氏菌引起的鹅的非肠道传染性疾病的总称、鹅大肠杆菌随着鹅日龄的不同可出现多种病型,主要有败血症型、浆膜炎型、肉芽肿型、气囊破裂型、蛋子瘟型、小鹅肿头型等。其中鹅的蛋子瘟型能导致大批种鹅发病和死亡,发病率最高达35%以上,致死率高达70%左右,而且致病性的大肠杆菌还可以穿过鹅蛋蛋壳引起鹅胚感染,造成死胎增多、孵出率下降和弱雏鹅增加。雏鹅及仔鹅发病率增高,鹅群一旦发病,则不易根除,其发病率达45%~90%,死亡率可达10%-47%。  相似文献   

7.
猪戊型肝炎病毒大庆株DQ1全基因序列分析   总被引:5,自引:0,他引:5  
本试验采用RT.-PCR的方法对戊型肝炎病毒大庆株(DQ1HEV株)的全基因进行分片段扩增,并对其两个末端采用末端快速扩增法(RACE)进行扩增、克隆,测序。与已报道的人的14株HEV的4个基因型的核苷酸和氨基酸进行比较,与IV型HEV的同源性最高。ORF1区与IV型HEV核苷酸的同源性为82.6%~83.6%.氨基酸同源性为93.5%,ORF2区与IV型HEV核苷酸的同源性为87.0%~88.4%,氨基酸同源性为95.8%~97.4%。ORF3区与IV型HEV核苷酸的同源性为94.4%~96.5%,氨基酸同源性为90.3%~96.5%。其结果表明DQ1 HEV株为IV型HEv。  相似文献   

8.
分别采用ELISA、多重PCR方法对从一个犊牛舍分离到的魏氏梭菌进行型别研究,结果显示:ELISA检测结果为88%的菌种属于A型,3.4%为C型,8.6%是D型;而多重PCR结果均为A型。  相似文献   

9.
采用微量凝集试验对山东省济南等4个市县的4种动和进行了军团菌LP1-14型及Lm血清学调查。结果表明,山东部分地区的畜禽存在着军团菌感染,抗体阳性率分别为:鸡19.61%;羊25.53%;牛14.52%;猪(兖州)22.03%和(菖南)26%。血清型分布广泛,鸡以LP1型占优势;羊以LP1,LP12型居多,牛以LP1,LP10和LP12型较高,兖州和菖南县猪均以LP10型为主。  相似文献   

10.
研制凝固型乳酸菌饮料不仅可添加不同风味物质和微量元素,而且仍须保持凝固型酸奶特有的风味和状态。本研究根据沉浮原理和食品增稠技术,筛选出当鲜奶稀释1倍,发酵剂量3%,蔗糖量9%时,添加增稠稳定剂羧甲基纤维素0.5%,明胶0.1%,海藻酸钠0.4%,三聚磷酸钠0.1%,经42℃8h发酵,可制成符合要求的凝固型乳酸菌饮料的初制品。  相似文献   

11.
Toxovars of 97 airborne C. perfringens isolates and 10 C. perfringens isolates from fecal samples of a calf stable were determined by an EIA procedure. Most airborne and fecal isolates belonged to toxovar A (88.7% and 80.0% respectively). Eight point two% of airborne C. perfringens were identified as toxovar C and 3.1% as toxovar D. Toxovar B was not found in the airborne state. Twenty% of fecal C. perfringens belonged to toxovar D. Toxovar B and C was not isolated from fecal samples. In addition, all fecal and air-borne isolates of C. perfringens toxovar D strains were analyzed in SDS-PAGE for their polypeptide pattern. All isolates from both sources exhibited the same polypeptide pattern after electrophoretic analysis in SDS-PAGE. Both results, determination of toxovars as well as polypeptide pattern analysis in SDS-PAGE, suggest that a major source of airborne C. perfringens in animal stables is animal feces.  相似文献   

12.
分别采用ELISA、多重PCR方法对从一个犊牛舍分离到的魏氏梭菌进行型别研究,结果显示:ELISA检测结果为88%的菌种属于A型,3.4%为C型,8.6%是D型;而多重PCR结果均为A型。  相似文献   

13.
Clostridium perfringens types A, B, C, D and E are known to cause severe enteritis/enterotoxaemia and diseases (especially caused by type A) belonging to the gas oedema complex in many species. Samples from the small intestine as well as faeces of domestic and exotic animals suffering from enterotoxaemic signs or having died within days after first occurance of toxaemia were submitted for typing C. perfringens toxovars by multiplex PCR. The following species have been investigated: domestic sheep (Ovis ammon; n = 10), domestic goat (Capra aegagrus hircus; n = 26), Japanese serow (Capricornis sumatraensis; n = 4), lechwe waterbuck (Hydrotragus leche; n = 1), blackbuck (Antilope cervicapra; n = 1), European reindeer (Rangifer tarandus tarandus; n = 4), domestic swine (Sus scrofa; n = 52), and collared peccary (Tayassu albirostris; n = 1). Interestingly, the predominant C. perfringens toxovar in domestic sheep was type A. This toxovar could also be diagnosed in all reindeer, in three Japanese serows, one lechwe waterbuck and most pigs (n = 47), the majority of those being at suckling age. Type D was the most prevalent toxovar (n = 18) in domestic goats, but also types A and E could be identified as pathogens in this species. Type C could only be found in domestic swine (n = 5) and in one case of clostridiosis in a Japanese serow. Two cases of enterotoxaemia in goats, one case in reindeer, and a single case in blackbuck and collared peccary were caused by C. perfringens type E. Genotyping of C. perfringens is recommended before starting vaccination programmes as it could be shown, that the importance of specific toxovars has been underestimated in specific species and/or age groups.  相似文献   

14.
In 1994 and 1995 leaves from eight browse feeds, containing tannins in different amounts (BF), were fed to West African Dwarf Sheep in Benin to evaluate their impact on Clostridium perfringens in the intestinal tract. An inhibitory impact of various BF on the growth of C. perfringens was assessed in in-vitro assays before, and thus a potential use of these leaves as a preventive diet against C. perfringens enterotoxemia in small ruminants was assumed. Surprisingly, an inhibitory impact of the BF on the shedding of C. perfringens in the feces of West African Dwarf Sheep could not be shown in seven of the eight BF examined. However, the pattern of inhibition of unlike C. perfringens toxovars may differ and a selective inhibitory impact of the BF Dialium guineense on C. perfringens toxovar D may be assumed.  相似文献   

15.
Using antigen capture and filter tests, 6,078 dogs throughout the state of Washington were examined for filariasis between July 1, 1997 and October 31, 1999. In western Washington, 791 males and 901 females examined were outdoors, not on prophylaxis, and had traveled out of the state; 6/791 (0.8%) males and 7/901 (0.8%) females were infected with Dirofilaria immitis (D. immitis), and one (0.1%) male and one (0.1%) female were infected with Dipetalonema reconditum (D. reconditum). There were also 392 males and 362 females examined that were outdoors, not on prophylaxis, and had not traveled out of western Washington. One (0.1%) female was infected with D. immitis, and two (0.5%) males and one (0.2%) female were infected with D. reconditum. In eastern Washington, 707 males and 826 females examined were outdoors, not on prophylaxis, and had traveled out of the state; 9/707 (1.0%) males and 4/826 (0.5%) females were infected with D. immitis, and no D. reconditum was found. There were also 376 males and 412 females examined that were outdoors, not on prophylaxis, and had not traveled out of the state. Three (0.8%) males and three (0.7%) females had D. immitis. One (0.2%) female had D. reconditum. Distribution of D. immitis-infected, nontravel dogs in eastern Washington was only found between 120 degrees and 119 degrees west longitude in the communities of Richland, Moses Lake, Okanogan, and Omak. Enzootic transmission of D. immitis and D. reconditum is occurring in both eastern and western Washington.  相似文献   

16.
Although cats are induced ovulators, the relationship between the day of breeding, the number of matings and the likelihood of ovulation and conception have not been extensively investigated. In this experiment, cats were mated either once or three times on day 1 or day 5 of oestrus to study the incidence of the LH surge, ovulation and conception rates. The percentage ovulating and the conception rates after a single mating on day 1 of oestrus were 60% (6/10) and 33.3% (2/6), respectively, and for cats mated once on day 5 of oestrus were 83.3% (10/12) and 40% (4/10), respectively. When cats were mated three times on day 1 of oestrus, the ovulation rates and conception rates were 70% (7/10) and 85.7% (6/7), respectively, and for those mated three times on day 5 of oestrus were 100% (10/10) and 100% (10/10), respectively. The concentration of LH did not increase in non-ovulating cats, and cats that were mated three times had LH concentrations that were numerically higher than those that were mated once. Litter size was neither related to the day of mating nor to the number of matings. Although an increase in the number of matings on day 1 of oestrus produced a numerically larger LH surge, it did not increase the ovulation rate, suggesting that plasma oestradiol concentrations were not sufficiently elevated to induce a high pituitary response to mating stimulation. The conception rate after a single mating was low, suggesting that the number of sperm per mating was not sufficient. These results suggest that mating more than once in the middle of oestrus is required to improve ovulation rates and conception rates in cats.  相似文献   

17.
Factors affecting mortality in finishing pigs   总被引:2,自引:0,他引:2  
Two groups of finishing pigs at a test station were studied to test the effect of initial weight, weight change in the 1st week, age, breed, and distance the pig was transported on mortality. Total mortality was 5.3% in 1 group and 6.3% in the other group. Specific causes of death were pneumonia (24.7%), gastric ulceration (14.0%), enteritis (6.4%), trauma (4.3%), gastrointestinal displacement (4.3%), rectal stricture (3.2%), porcine stress syndrome (3.2%), and brain abscess (2.2%). Other categories for cause of death were miscellaneous (6.5%), and undiagnosed (31.2%). More pigs died in the last 6 weeks of the 18-week finishing period than in the 1st 6 weeks (P less than 0.05). Death rates were not significantly different between pigs that lost weight and pigs that maintained or gained weight during the 1st week after arrival at the test station. The mean transportation distance to the test station was not significantly different between pigs that died and pigs that survived. Transportation distance was not correlated with mean daily gain. The death rate was significantly (P less than 0.03) higher for Yorkshire pigs than for crossbred, Poland China, Hampshire, and Duroc pigs, and it was significantly (P less than 0.01) higher for Berkshire, Spot, and Chester White pigs than for Hampshire and Duroc pigs.  相似文献   

18.
Locoweed species (Astragalus and Oxytropis spp.) are a serious toxic plant problem for grazing livestock. Horses and sheep have been conditioned to avoid eating locoweed using the aversive agent LiCl. The objective of this study was to determine if previous locoweed intoxication affects food aversion learning in horses and sheep. Horses and sheep were divided into 3 treatment groups: control (not fed locoweed and not averted to a novel feed); locoweed-novel feed averted (fed locoweed and averted to a novel feed); and averted (not fed locoweed and averted to a novel feed). Animals in the locoweed-novel feed averted groups were fed locoweed during 2 periods of 21 and 14 d, respectively, with each feeding period followed by a 14-d recovery period. Animals were averted to a novel test feed at the end of the first locoweed-feeding period, and periodically evaluated for the strength and persistence of the aversion. During the first recovery period, locoweed-novel feed averted horses ate less (9.5% of amount offered) of the test feed than did control horses (99.8%) and did not generally differ from averted horses (0%). During recovery period 2, locoweed-novel feed averted horses (4.3%) differed (P = 0.001) in consumption (% of offered) of the test feed from controls (100%) and the averted group (0%). Locoweed-novel feed averted sheep differed (P = 0.001) from controls (14.4 vs. 99.5%, respectively, during recovery period 1), whereas locoweed-novel feed averted sheep did not differ (P > 0.50) from averted sheep (0.6%). During the second recovery period, control sheep (100%) differed (P < 0.05) from averted (0%) and locoweed-novel feed averted (12.2%) groups. Two intoxicated sheep (locoweed-novel feed averted) partially extinguished the aversion during the first recovery period, but an additional dose of LiCl restored the aversion. Two of 3 intoxicated horses had strong aversions that persisted without extinction; 1 horse in the locoweed-novel feed averted group had a weaker aversion. These findings suggest that horses and sheep previously intoxicated by locoweeds can form strong and persistent aversions to a novel feed, but in some animals, those aversions may not be as strong as in animals that were never intoxicated.  相似文献   

19.
This study was designed to evaluate the haemostatic suture as a means of preventing haemorrhage from the hysterotomy in mares after caesarean section. At 2 university hospitals 1982-1994, 48 mares had caesarean section for dystocia, 10 as an elective, and 8 mares concurrently with colic surgery. The haemostatic suture was used in 31 of 66 mares (47%) and surgery period was significantly (P<0.05) shorter when it was not applied. Anaemia (PCV<30%) was recorded in 13 (22%) of 58 mares, excluding the colic group, and the haemostatic suture did not after this proportion of mares that had anaemia. Anaemia was 5 times more probable following caesarean section than vaginal delivery, evidence that bleeding from the hysterotomy is a serious and common complication of caesarean section in mares. Severe uterine haemorrhage was recorded in 3 mares that had an haemostatic suture (10%) and in 2 mares that did not (6%). The latter two mares died of haemorrhage. The suture, therefore did not eliminate post operative anaemia and severe uterine haemorrhage. If omitted, the hysterotomy should be closed with a full thickness pattern that is sufficiently tight to compress vessels in the uterine wall.  相似文献   

20.
OBJECTIVES: To determine whether vaccination with a killed vaccine prevents fecal shedding of Mycobacterium avium subsp paratuberculosis, to compare effectiveness of a culture and cull program in vaccinated and nonvaccinated herds, and to compare paratuberculosis-related preventive management in vaccinated and nonvaccinated herds. SAMPLE POPULATION: 58 commercial Dutch dairy herds. DESIGN: Cross-sectional study (study A) in vaccinated (n = 25) and nonvaccinated (29) herds of dairy cows. Longitudinal study (study B) in vaccinated (n = 2) and nonvaccinated (2) herds of dairy cows. PROCEDURE: In study A, fecal samples were obtained from adult cows in herds with and without a history of vaccination with a killed vaccine. Management measures were evaluated. In study B, fecal samples were obtained 4 times at 6-month intervals from cows older than 6 months. Cows that had positive test results were removed from the herd directly after the outcome of the culture. RESULTS: In study A, differences were not detected among the 25 herds that were vaccinated; culture results were positive for M avium subsp paratuberculosis in 4.4% of herds. In 29 herds that had not been vaccinated, culture results were positive in 6.7%. In study B, the percentage of positive results on culture decreased from 10.9% and 5.7% to 3.5% and 0%, respectively in the 2 vaccinated herds. In the 2 nonvaccinated herds, percentages decreased from 6.1% and 16.5% to 0% and 2.3%, respectively. Management practices were different between herds that were vaccinated and herds that were not; owners of herds that were not vaccinated followed more preventive management procedures and practiced less feeding of raw milk to calves. CONCLUSIONS AND CLINICAL RELEVANCE: Vaccination of calves with a killed vaccine does not prevent transmission of M avium subsp paratuberculosis; therefore, hygienic practices remain essential in herd management.  相似文献   

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