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1.
<正>奶牛受胎率的高低直接关系到奶牛养殖场(户)的经济利益。如何提高奶牛受胎率,多年以来一直是奶牛工作者关注的课题和努力的方向。影响奶牛受胎率的因素很 相似文献
2.
本文对奶牛高、中、低产奶量的泌乳曲线进行对比分析．以探索低产奶牛产奶量低的原因。结果表明，低产奶牛泌乳高峰持续期一般较短。在生产上，可将奶牛泌乳高峰月提前．以延长奶牛泌乳高峰期的持续时间，提高奶牛产奶量。 相似文献
3.
西北农区奶牛遗传改良与DHI测定分析 总被引：1，自引：1，他引：0
通过调研西北五省农区的奶牛养殖现状,收集有关遗传改良和生产性能数据资料,并加以统计分析。讨论了西北农区奶牛遗传改良工作中现存问题,认为奶牛DHI测定体系对奶牛养殖的生产与管理具有重要意义,提出了今后发展与完善奶牛遗传改良工作和DHI测定体系的建议和措施,为进一步加快西北五省农区奶牛遗传改良工作和提高奶牛生产性能水平,具有一定的参考价值。 相似文献
4.
河南省奶牛病毒性腹泻-黏膜病血清学调查 总被引：2，自引：0，他引：2
摘要： 为了解河南省奶牛病毒性腹-黏膜病的发生情况,2009年5月对河南省的豫东、豫西、豫南、豫北和郑州市五区域20个奶牛小区的355头奶牛,随机采血,采用ELISA方法,检测奶牛病毒性腹泻-黏膜病血清抗体,结果显示20个奶牛小区有17个奶牛小区感染有病毒性腹泻-黏膜病病毒,场感染率为85%,各小区奶牛病毒性腹泻-黏膜病检测阳性率在0-88.24%,血清阳性率平均为53.8%,表明该病在河南省奶牛中感染率较高。 相似文献
5.
近年来,农五师奶牛养殖业发展迅速,但由于多方面的原因,一些奶牛的常发疾病给奶牛养殖业带来了不必要的损失,其中奶牛的胎衣不下是危害较为严重的一种.胎衣不下是指奶牛产后超过12 h后胎衣仍然不能排除,常引起子宫炎症,影响再次怀孕和产奶,严重时危及奶牛生命.为找到奶牛胎衣不下的原因,制定有效的防治措施,我们进行了相关的调查和分析. 相似文献
6.
奶牛养殖规模效益分析 ——以黑龙江省为例 总被引：1，自引：1，他引：0
通过对黑龙江省不同奶牛养殖规模的饲养成本和经济效益等问题进行调查研究,系统、全面的了解了黑龙江省奶牛养殖的成本和效益现状,提出走适度规模化、农牧结合的发展道路,实现科学的奶牛饲养管理,着力提高奶牛单产水平,改变原料乳增长方式,努力实现奶牛养殖由数量型向质量型战略转移,是提高黑龙江省奶牛养殖经济效益的主要途径。 相似文献
7.
8.
时利珍 《农产品加工．学刊》2006,(9):77-78
通过加强夏季奶牛的10项饲养管理措施,以达到防暑降温和防止奶牛中暑等疾病发生的目的,可以有效增强奶牛的体质,提高奶牛的产奶量和经济效益。 相似文献
9.
为了更好的了解不同胎次奶牛血液生理生化指标的变化规律，进一步指导实际生产工作，本试验选用体况相近的不同胎次荷斯坦奶牛，对奶牛的血液样品进行血常规指标和血液生化指标检测。结果表明：血常规测定发现5胎奶牛白细胞数量明显增多，显著高于2-4胎奶牛(P＜0.05)；2-4胎奶牛红细胞数显著高于5胎和1胎奶牛的红细胞数(P＜0.05)；1胎奶牛的血红蛋白却显著高于2-5胎奶牛；5胎奶牛的中性粒细胞百分数显著升高(P＜0.05)。血液生化测定发现1胎奶牛内ALKP的含量与钙离子浓度显著都高于2-4胎(P＜0.05)，趋势都是随着胎次的增加含量逐渐降低。结论得出母牛胎次与血液生理生化指标具有一定的相关性，可为不同胎次母牛的饲养管理提供依据。 相似文献
10.
中国近代奶牛传入与引进的研究进展 总被引：1，自引：1，他引：0
对近代以来,被带到中国大陆以及台湾、香港地区的奶牛品种进行了研究探讨。笔者指出了近代奶牛通过被殖民地当局传入、中国企业从国外购买2种途经进入中国。结果揭示了中国不同地区的奶牛种质来源和品系之间的血缘关系,归纳了中国奶牛品种传入的4个特点：（1）奶牛品种繁多;（2）引进的海关口岸多;（3）传入的主体多;（4）延续时间长。由于这些特点的作用,近代传入中国的奶牛几乎涵盖了当时世界上主要的奶牛品种,血缘系统十分复杂,由此形成了中国的奶牛种质多样性来源。 相似文献
11.
Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts 总被引：7，自引：0，他引：7
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed. 相似文献
12.
C. J. Spurr D. A. Fulton P. H. Brown R. J. Clark 《Journal of Agronomy and Crop Science》2002,188(4):275-280
Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality. 相似文献
13.
Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans. 相似文献
14.
G. H. Kroon 《Euphytica》1994,76(1-2):125-125
Summary
K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes. 相似文献
15.
Hongyan WEI Jian ZHOU Jinguang LU Jingzheng SONG Qiongxi YU Zhihong JIANG 《Medicinal Plant》2019,(6):27-29
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol... 相似文献
16.
Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed. 相似文献
17.
Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes. 相似文献
18.
W. Erskine M. Tufail A. Russell M. C. Tyagi M. M. Rahman M. C. Saxena 《Euphytica》1993,73(1-2):127-135
Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed. 相似文献
19.
Mohammed Riyazaddin Polavarapu B. Kavi Kishor Are Ashok Kumar Belum V. S. Reddy Rajendra S. Munghate Hari C. Sharma 《Plant Breeding》2015,134(4):423-436
Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums. 相似文献
20.
Herbage yield trials are necessary to test if candidate varieties are well suited for organic conditions. In order to elucidate
a particular suitability for organic conditions, we run such trials in parallel under both organic and conventional conditions.
Here, we report on second and third year results of the sowings 2004 and 2005. These trials are part of a targeted breeding
programme for organic conditions. Irregular colonisation of pure grass plots with adventitious plants, in particular white
clover, was recognized as a major constraint to the quality of the results obtained under organic conditions. The coefficients
of variance in dry matter yield almost doubled when compared to conventional trials, and significant differences in annual
yield among varieties were rare. However, when herbage yield was corrected for the estimated fraction of adventitious plant
colonization at each cut, the number of instances with statistically significant differences for annual yield among varieties
increased more than fourfold. Dry matter yields under organic and conventional conditions were significantly and positively
correlated. However, analysis of variance showed a significant culture type by variety interaction for annual dry matter yield
in 12 out of 24 trials. When diploid and tetraploid varieties of the same Lolium species were tested in one common trial, only tetraploid varieties were identified as being particularly well suited for organic
conditions, while in these trials, the great majority of apparently poorly suited varieties were diploid. This suggests that
breeding tetraploid Lolium varieties is promising when aiming at a favourable response to organic agriculture. 相似文献