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1.
Abstract. The feasibility of including individual records on correlated traits in a family selection programme which aims to increase resistance to furunculosis in Atlantic salmon was studied; markers were selected because of their potential role in the pathogenesis of the disease. Fibrinogen and α2-antiplasmin both show genetic variation; both are correlated with survival after challenge with Aeromonas salmonicida , the correlation being 0·44 and 0·37 ( P < 0·05), respectively, and it is possible to measure both on a large scale at low costs. Contrary to α2-antiplasmin, fibrinogen was negatively correlated with survival due to furunculosis within the 10 most resistant families and within the 10 most susceptible families in contrast to an overall positive correlation. This inconsistency could be attributable to the presence of different allelic phases in different families, and of major linked loci influencing survival and fibrinogen levels. Thus, only α2-antiplasmin fulfils the requirements for a marker trait for resistance to the disease suitable for individual selection at the population level, whereas the use of fibrinogen would be restricted to within family selection. The full statistical model explained 51% of the variation in resistance to furunculosis, and α2-antiplasmin contributed 15% to this variation when considered as a separate entity. Thus, the additional gain from including individual records on α2-antiplasmin in a family selection programme could be significant.  相似文献   
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基于改进Bayes抠图算法的麦穗小穗自动计数方法   总被引:1,自引:1,他引:0  
小麦产量评估需人工获取田间单位面积的麦穗数和麦穗小穗数,往往耗时耗力。为了实现高效、自动地麦穗小穗计数,提出一种基于改进Bayes抠图算法的麦穗小穗自动计数方法。该方法首先利用改进Bayes抠图算法对获取地自然生长条件下的麦穗图像进行抠图,将麦穗从自然背景中分割出来。然后对该图像进行平滑滤波和二值化,运用迭代极限腐蚀运算对二值化图像进行腐蚀处理,去除麦穗图像中的麦芒,分离出麦穗上每个单独的麦穗小穗。再运用面积滤波滤除掉面积过小的区域,对剩余区域的黑洞进行填充,由此每个单独的麦穗小穗形成一个单独的连通区域,最后对连通区域进行标记和计数,完成麦穗小穗的自动计数。使用4个小麦品种的麦穗图像对麦穗上的小穗进行计数验证,结果表明,该方法在识别4个品种田间麦穗单幅图像中小穗数量的平均计数精度达到94.53%,平均相对误差为5.47%,对比已有麦穗小穗自动计数方法,计数精度显著提高,这对于小麦在线产量预估具有重要意义。  相似文献   
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在系统可编程技术将数字系统的设计过程由书面设计──硬件搭配──制做样机改变为书面设计──仿真──制做样机,避免了搭试的诸多弊端。其关键环节仿真,是计算机发展和可编程器件使用的共同结果。  相似文献   
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通过引种栽培宁丰系苹果试验研究,阐明宁丰系苹果引种栽培关键技术环节,了解宁丰系苹果的生物学特性、适应性及生长表现,为以后更广泛地开展推广宁丰系苹果引种栽培积累技术资料。  相似文献   
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Intake, growth and carcass yield of indigenous goats fed basal diets of market wastes of sweet potato (Ipomoea batatas) vines (SPV) and scarlet eggplant (Solanum aethiopicum) (SEP) were examined in two experiments. In experiment I, the effect of presentation method (chopping, hanging or adding molasses) on the intake of SEP and SPV was evaluated. Presentation method did not influence the intake of SPV while hanging resulted in the highest (P < 0.05) intake of SEP. In experiment II, 24 male growing goats were supplemented with a concentrate (25% cottonseed cake +75% maize bran) in four dietary groups: SEPD, SPVD, SEP+SPV and Control where elephant grass (Pennisetum purpureum) was offered as the roughage. SEP were offered by hanging, while SPV were chopped. The goats were slaughtered after 12 weeks of feeding. Goats in the SEPD group constantly lost weight, hence were not followed to the end. Average daily gain and hot carcass weight were highest (P < 0.05) in the SPVD group (44 g/d and 8.4 kg, respectively), but similar between the SEP+SPV (19 and 6.8) and Control (21 and 6.9) groups. In conclusion, SPV can support goat meat production where standard feed resources are scarce when fed with an energy-protein concentrate. SEP are poorly consumed by goats, hence cannot be used as their sole basal feed.  相似文献   
9.
Parkia biglobosa is an important traditional economic tree legume of considerable multipurpose potentials that has not been well researched. It is used for fodder, human food, fuel wood, timber, green manure, medicine, provides shade for forage grasses and livestock and protects soil from heat and it is important in soil nutrient cycling.The objective of this study was to determine the effect of management regimes (cutting frequency and height) on the coppicing ability, fodder production, and nutritive value potentials of cultivated Parkia trees. This initial study has shown that the tree has a potential as fodder for livestock as well as human food and should be further studiedto fully understand its biology, agronomy and feeding value under various agroforestry or silvopastoral systems of humid tropics in West Africa.  相似文献   
10.
San Martin, B., Cornejo, J., Lapierre, L., Iragüen, D., Pérez, F., Hidalgo, H., Andre, F. Withdrawal time of four pharmaceutical formulations of enrofloxacin in poultry according to different maximum residues limits. J. vet. Pharmacol. Therap. 33 , 246–251. To ensure delivery of safe animal products to consumers, the withdrawal time (WDT) of drugs must be respected. Property differences among pharmaceutical formulations, for the same drugs, can lead to differences in the WDTs estimation. The WDTs of four commercial formulations of enrofloxacin (ENRO) in broiler chickens, considering MRLs established by different countries, were studied. Two hundred‐thirty‐four broiler chicks were allotted among four groups; the formulations were orally administered daily with 10 mg/kg bw. After treatment, six chickens of each group and two controls were slaughtered daily until day 9 post‐treatment. Samples of muscle and liver were collected, and analyzed using HPLC‐MS‐MS. The WDTs among formulations of ENRO showed differences of 24 and 48 h. Based on the European Community and Chile MRLs of 100 μg/kg (muscle) and 200 μg/kg (liver), the WDTs did not exceed 5 days. When Japan MRL was considered (10 μg/kg,), the WDTs increased up to 8 days. These results indicate that for WDTs determination, the differences among pharmaceutical formulations of a drug must be considered as well as the MRLs.  相似文献   
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