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A. J. Haverkort M. Bicamumpaka 《European journal of plant pathology / European Foundation for Plant Pathology》1986,92(5):239-247
It became apparent from chemical late blight control data on large numbers of genotypes of the Rwandese late blight screening programme, that yields were linearly related to the amount of intercepted radiation by the crop. Measures which affected the total amount of intercepted radiation such as the use of contact and systematic fungicides, or of different genotypes, did not affect the radiation use efficiency of the canopy. Genotypes that started to tuberize at relatively low values of intercepted radiation partly escaped the effect of late blight infection of the foliage on tuber yields. This characteristic could be useful to identify early late blightresistant genotypes for central Africa, where farmers grow two crops per year and earliness is required.Samenvating De chemische bestrijding van de aardappelziekte in grote aantallen genotypen van het Rwandese veredelingsprogramma voor aardappelziekteresistentie heeft aangetoond dat opbrengsten zich lineair verhouden tot de hoeveelheid door het gewas opgevangen zonnestraling. Maatregelen die van invloed waren op de totale hoeveelheid opgevangen straling, zoals het gebruik van contact- of systemische schimmelbestrijdingsmiddelen, of van verschillende genotypen, waren niet van invloed op het rendement van het gebruik van zonnestraling door het blad. Genotypen die een knolaanleg vertoonden bij verhoudingsgewijze lage waarden van opgevangen straling, ontsnapten gedeeltelijk aan het effect van bladaantasting op knolopbrengst. Dit kenmerk zou van nut kunnen zijn om vroege genotypen te zoeken met resistentie tegen de aardappelziekte in centraal Afrika, waar vroegheid van belang is omdat boeren twee gewassen per jaar telen. 相似文献
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CHRISTOPHER P. OBER TIM C. SPOTSWOOD ROBERT HANCOCK 《Veterinary radiology & ultrasound》2006,47(2):153-158
A cat with a 1-year history of oropharyngeal foreign bodies was diagnosed with a pharyngeal diverticulum. The cat experienced fatal cardiac arrest during endoscopy, and postmortem radiographs and ultrasound revealed venous air embolism. Venous air embolism is uncommonly reported in veterinary medicine, but is a risk during any procedure that introduces air into a body cavity. Precautions should be taken during these procedures to help minimize the risk of adverse events. 相似文献
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T.M. Brown-Brandl J.A. Nienaber R.A. Eigenberg T.L. Mader J.L. Morrow J.W. Dailey 《Livestock Science》2006,105(1-3):19-26
Heat stress in cattle causes decreases in feed intake and feed efficiency; in extreme cases, it can cause death. These losses amount to millions of dollars each year. A study was designed to determine severity of heat stress among four breeds of cattle. Throughout two summers, 256 feedlot heifers of four different breeds were observed. Respiration rates, panting scores, and surface temperatures were taken twice each day on 10 animals/breed for several weeks during the summers of 2002 and 2003. Twenty-four-hour behavior measurements were recorded for four heat-stress and four thermoneutral days. Results showed during the afternoon, Angus cattle (black) had the highest respiration rates, panting scores, and surface temperatures, followed by the MARC III (dark red), Gelbvieh (tan), and Charolais (white). Behavior data showed that heat stress increased drinking and standing behavior, and decreased eating, lying, and agonistic behaviors, and that dark-hided cattle adjusted their behavior more than light-hided cattle. Overall, it was found that breed of cattle with dark-hides were more affected by temperature changes and at peak temperatures than breeds of cattle with light-hides. 相似文献
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In this study, we investigated the effect of ascorbic acid (AA) administration on goat excitability due to transportation. Ten goats administered AA (p.o.) at 100 mg/kg of body weight before transportation served as the experimental group, and seven goats administered only 10ml/kg of sterile water (p.o.) served as controls. Excitability scores were recorded for each goat; when weighed, before, immediately after, and 3 h after 8 h of transportation. A score of one to four was allocated to each goat; higher scores represent greater excitability. Immediately after transportation, excitability scores decreased significantly, especially those of control goats (p < 0.001). At 3 h post-transportation, the excitability scores of animals in the experimental group were not significantly (p>0.05) different from their pre-transportation normal values, whereas those of control goats were significantly lower (p < 0.01). The correlation i.e. the relationship between excitability score values and percent excitability (percentage of goat with particular excitability score) for different excitability score group 3 h post-transportation was positive and highly significant (p < 0.001), in both experimental and control goats. Our results indicate that road transportation induces considerable stress (depression) in goats as evidenced by a lower excitability score post-transportation. Moreover, the administration of AA pre-transportation facilitated the transition from a state of depression to excitation. In conclusion, AA administration to animals prior to transportation may ameliorate the depression often encountered after road transportation. 相似文献
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牛TLR4基因的遗传多态性与乳房炎的关联分析 总被引:10,自引:2,他引:10
TLR4通过识别病原体而激活免疫细胞,在先天免疫和适应性免疫防御中起着重要作用。以中国荷斯坦奶牛、三河牛和中国西门塔尔牛共397头为研究对象,利用创造酶切位点PCR法扩增243bp的目的片段,通过限制性内切酶HinfⅠ酶切来检测TLR4第3外显子的多态性,结果发现扩增产物的27bp处C到T的突变使得多态位点产生,编码的氨基酸由苏氨酸变为异亮氨酸。A、B2个等位基因在3个群体中均有分布,A等位基因占优势(大于78%),经χ^2适合性检验,三河牛在该位点未达到Hardy-Weinberg平衡状态(P〈0.05)。运用SAS8.2软件采用最小二乘法拟合线性模型,将该基因座不同基因型与奶牛乳房炎进行了关联分析,结果表明:AA基因型为乳房炎抗性基因型(P〈0.05),A等位基因为乳房炎抗性的有利基因。 相似文献
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对240头牦母牛进行为期一年的体况评分监测,发现牦母牛体况变化与草地饲草的供给状况相一致,牦母牛体况变化基本规律为暖季表现为快速上膘,冷季呈现逐步消耗。体况评分最低的时期为5~6月份,最高在10月和11月份。体况消长变化呈现两年一周期的模式。 相似文献
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GAO Qing SHI Jizhen YANG Zhichao LUO Sunlin ZHANG Siwei HUANG Shangzhen ZHANG Hailiang LI Junwei GUO Gang WANG Yachun 《中国畜牧兽医》2007,47(12):4016-4023
To investigate the influencing factors of locomotion score (LS) and its impacts on production performance and blood routine index in Holstein,body condition score (BCS),LS and DHI (dairy herd improvement) of 1 486 lactating cows from two dairy farms,and the blood routine indexes of 101 lactating cows from one farm in Beijing were measured.The fixed model was used to analyze the impacts of herd,parity and lactation stage on LS,and the impacts of LS and BCS on daily milk yield,somatic cell score,milk composition and blood routine indexes in dairy cows.The results showed that both parity and lactation stage had significant impacts on LS.The LS increased with the increase of parit,the LS increased by 0.71 from first lactation to fifth and above lactation.The LS of cow in lactation stage Ⅲ(100-199 d) and Ⅵ (after 350 d) were significantly higher than cow in stage Ⅱ (45-99 d)(P<0.05),and both were higher than 2.The LS had no significant impacts on daily milk yield,milk composition and somatic cell score (P>0.05).However,the milk yield of the cow with LS≥4 was the lowest,and a decrease of 2.29 kg was found compared with the cow with LS=1.Among the various blood routine indexes,LS had significant impacts on red blood cell count,hemoglobin content,mean corpuscular hemoglobin concentration and lymphocyte count (P<0.05),and had no significant impacts on white blood cell count (P>0.05).With the increase of LS,the red blood cell count,hemoglobin content,mean corpuscular hemoglobin concentration and lymphocyte count of cows decreased with different extents.There were some problems on the body immunity and hematopoiesis of cows with poor LS.In dairy farm,regular evaluation of LS could be used to find the management problems of feet and legs,which had a great significance to reduce the loss of production performance and early culling caused by hoof disease. 相似文献