Relevance of the variability of kidding day in Creole goats in Guadeloupe     

N. Mandonnet  G. Alexandre  M. Navès 《Livestock Production Science》2005,92(3):241-247

The results of 5732 records of kids born between 1985 and 1996 at Gardel Agricultural Experiment Station (INRA) in Guadeloupe, were used in order to estimate the effect of kidding day (KD) on individual preweaning growth performances, total productivity of Creole goats and litter size. The flock was subjected to a restricted mating season for a long time, by using male effect. The results of the fixed linear model showed a highly significant (P<0.001) effect of KD on growth rate and total productivity of does. Live weights of kids born around the 21st day of the kidding period (KP) was 4% to 7% higher than those of kids born the first day of the KP. For total productivity of does, this ratio did not reached more than 4%. The optimum at 70 days of age occurred around 14th day of the KD with 3% of improvement of total productivity. No effect was observed upon litter size. The genetic (co)variance components were estimated by six different Individual Animal Models. The heritability (h²) estimated from the best model, was h_D²=0.25±0.05 for genetic direct effect; h_M²=0.09±0.04 for genetic maternal effect and the genetic correlation between direct and maternal effects was −0.86±0.12. The use of KD could be highly recommended in a breeding program in this population of Creole meat goats, since it is quite easy to record under commercial conditions as a character related to reproductive performance.  相似文献   

高寒地区不同建植期人工草地群落垂直结构和生产力变化的研究   总被引：4，自引：0，他引：4  

王长庭龙瑞军  施建军丁路明 《中国草地》2005,27(5):16-21

对高寒地区不同建植期人工草地群落垂直结构和生产力的变化研究结果表明：（1）随着人工草地建植时间的延长,人工草地群落垂穗披碱草高度异质性逐渐减小.（2） 不同建植期（1999、1998、1997年建植）人工草地垂穗披碱草和群落平均地上生物量均主要分布在0 ～20cm冠层中,约占平均地上生物量的61.03%、90.64%、84.55%和67.47%、92.54%、86.08%.（3） 不同建植期 （1999、1998、1997年建植）人工草地群落平均地下生物量均主要分布在0～10cm土层中,约占地下总生物量的85.97%、81.73%和78.47%.（4） 建植的人工草地如果其组分单一,即物种的丰富度很低时,均匀度增加,物种对环境资源的竞争力和利用率提高,导致土壤资源库中某些营养成分缺乏,草地群落初级生产力因此而降低。  相似文献   

立地条件和林分结构对有林地生产力的影响     

李晨燕 《安徽农业科学》2015,(5):159-160,184

通过分析有林地生产力与立地条件和林分结构中各因子的关系,探索制约有林地生产力的主要因素.结果表明:不同立地质量中Ⅰ类地单位蓄积量最高(268.86±20.24 m3/hm2),不同坡向中东坡单位蓄积量最高(269.78±38.54 m3/hm2),不同树种组成中10杉类型单位蓄积量最高(259.33±14.62 m3/hm2);有林地生产力与林分年龄、林分密度正相关,相关系数R分别为0.590、0.460;有林地生产力与海拔、坡度相关性不显著.以上结果说明立地质量、坡向和树种组成对有林地生产力影响显著;有林地生产力与林分年龄、林分密度相关,与海拔、坡度无关.  相似文献   

Attributes of wheat cultivars for late autumn sowing in genes expression and field estimates     

《European Journal of Agronomy》2016

Due to the growing interest in Central and Eastern Europe on cropping of wheat in optional late autumn terms, called facultative, genetic research and field evaluation were taken on four spring cultivars: Tybalt (NL), Monsun (DE), Ostka Smolicka (PL) and Bombona (PL), currently being recommended by breeders. The PPD gene analyze, expression level of dehydrine genes (WCS120 and WDHN13) in cooling test, and qPCR for RNA isolation and analyses of WCS120 and WDHN13 gene expression at the BBCH12 stage of wheat were estimated. Molecular analysis of PPD-D1 gene confirmed the presence of photoperiod sensitive allele ppd-D1b in all tested genotypes. The highest level of NRE WCS120 gene was detected in cultivars Tybalt and Bombona. Two-year field experimental study assessed the growth, development and productivity of facultative and spring crops of studied cultivars. Based on our results from field experiments and result of molecular analysis of alleles of PPD-D1 gene, the tested genotypes can be considered as potentially facultative genotypes.  相似文献   

鸡白痢鸡伤寒对种鸡生产性能的影响   总被引：2，自引：0，他引：2  

时倩  潘玲  周杰 《吉林农业科学》2011,(4)

鸡白痢鸡伤寒是一种经蛋垂直传播且具有严重危害性的传染病。为在种鸡群中进行血清学检查,检出并淘汰阳性鸡以确保无白痢的健康种鸡群,达到种群净化的目的,本研究应用全血平板凝集试验对江苏太仓广东温氏家禽有限公司某种鸡场的5133羽新兴黄鸡进行了检测。检测结果:鸡白痢鸡伤寒的抗体阳性检出率为2.7%。在相同的饲养环境下通过为时40 d试验,对阳性鸡群与阴性鸡群的产蛋率,受精率及孵化率进行比较观察,结果表明:鸡白痢鸡伤寒抗体呈阳性鸡群的上述生产性能在不同程度上低于抗体呈阴性鸡群。鸡白痢疾鸡伤寒阳性带菌鸡群的产蛋率、受精率、孵化率分别低于鸡白痢阴性鸡群为8.1%～21.8%、0.87%～1.6%、10.6%～11.4%。  相似文献   

生产力促进中心咨询诊断服务的SWOT分析     

薛强  赵静 《湖南农业大学学报(自然科学版)》2013,(4):69-74

生产力促进中心自建设发展以来，形成了多样化的服务业务。其中，咨询诊断服务不断衍化发展，已经成为服务中小企业的重要手段，积累了一定的优势，也存在着劣势。面对科技服务业迅猛发展的态势，生产力促进中心开展咨询诊断服务面临机遇与挑战并存的局面，通过基于SWOT分析法构建的评价模型，明确主要影响因素，进而推演出下一步发展的具体路径。  相似文献   

种植方式对青海湖流域人工草地植被和土壤养分特征的影响     

李彩弟  张春平  俞旸  杨晓霞  杨增增  冯斌  张小芳  刘玉祯  魏琳娜  孙彩彩  董全民 《草地学报》2023,31(2):471-478

为探究多年生人工草地在青海湖流域的适应性和稳定性,本研究以青海草地早熟禾(Poa pratensis. Qinghai)和青海中华羊茅(Festuca sinensis. Qinghai)单播及混播人工草地为研究对象,分析不同种植方式下人工草地植被和土壤养分特征的变化。结果表明：青海草地早熟禾+青海中华羊茅混播草地和青海草地早熟禾单播草地的生物量和盖度高于青海中华羊茅单播草地,且在生长旺期(8月),青海草地早熟禾+青海中华羊茅混播草地生物量最高,为586.2 g·m^-2;青海草地早熟禾单播、青海中华羊茅单播和青海草地早熟禾+青海中华羊茅混播草地间土壤有机质、全氮、全磷、硝态氮、铵态氮和土壤含水量在相同土壤深度下差异不显著,但土壤氮、磷及有机质间存在显著的相关性。综上所述,在青海湖流域建植青海草地早熟禾+青海中华羊茅混播型人工草地可以获得较高的产量,但需在种植和管理过程中协调好土壤氮、磷间的关系。  相似文献   

香菇夏季不同栽培模式对产量的影响研究     

王健 《南方园艺》2013,(6):11-13

研究了香菇在夏季栽培中的露地栽培、半地下式栽培、半覆土栽培等3种不同栽培模式对产量的影响。比较表明：半覆土栽培的较有优势，生物转化率高。  相似文献   

全球气候变化对我国干旱区影响分析     

赵名茶 《干旱区资源与环境》1993,(Z1)

<正> 全球变暖问题已经是全世界关注的焦点,不仅各国科学家们进行了大量的研究,各国政府也耗费巨资组成了政府间专家组(IPCC,Intergovernmental panel on ClimateChange研究气候变化的影响。IPCC包括3个工作组,Ⅰ.科学分析工作组(Working  相似文献   

Soil tillage for crop production and for protection of soil and environmental quality: a Scandinavian viewpoint     

Inge H  kansson 《Soil & Tillage Research》1994,30(2-4):109-124

Based on experience from 35 years of tillage research in Sweden, future development of soil tillage is discussed and some research problems are identified. Tillage and seeding methods must be more carefully adapted to conditions at individual sites and occasions. Low-pressure typres, better weed control and improved seed coulters favour the increased use of reduced tillage. In order to diminish the impact of agriculture on the environment, it is necessary to develop methods for establishment of crops in the early spring or immediately after harvest, even in soils with large amounts of crop residues or high moisture content. The roles of tillage methods, and of soil compaction and structure on environmental impact of agriculture must be investigated. World food production must increase, since the world population is rapidly increasing. Therefore, it is necessary to develop improved crop production systems, including crop establishment systems, which favour efficient use of basic crop growth factors, while protecting or increasing soil productivity. Compaction, decreased organic matter content, and erosion are important long-term threats to soil productivity.  相似文献