Availability and use of dry season feed resources on smallholder dairy farms in central Kenya

A cross-sectional survey on 41 farms followed by six weeks monitoring of dairy cattle feeding on ten smallholder dairy farms in central Kenya was conducted to investigate the use, availability and quality of dry season feed resources. Fodder production was largely from Napier grass (Pennisetum purpureum) grown on small plots and contour strips where it acts both as a fodder source as well as a biological barrier to soil erosion. There is a need to broaden the choice of fodder crops on such farms to provide a wide range of harvesting management options and to avoid total loss in case of pest or disease outbreaks. Intercropping of Napier grass with leguminous fodder trees could boost the quantity and quality of herbage production especially during the dry season. Roughage from a variety of sources was utilised during the dry season in addition to Napier grass. Among the herbages, leguminous feeds had the lowest potential dry matter degradability while weeds harvested from cropland and roadsides had the highest. Energy and protein intake from the roughage fed to grade dairy cattle during the dry season may be insufficient to meet the requirements of these animals due to the high levels of fibre concentration (acid detergent fibre and neutral detergent fibre (ADF and NDF)) in them. It is recommended that the scope for alternative sources of improved roughage such as Napier/calliandra mixtures, to boost the energy, protein and overall dry matter provision on the farms should be investigated further.This revised version was published online in November 2005 with corrections to the Cover Date.     

矮象草天然色素的研究

探讨了不同加工方法,没贮存条件及不同贮存时间对矮象草天然色素含量的影响。试验结果表明：矮象草叶粉含有较丰富的天然色素。经低浊烘干处理后的叶黄素含量比高温烘干处理的高;无氧贮存比有氧贮存叶黄素含量高,损失率低,且差异极显著;随着贮存时间的延长,叶黄素的含量有所下降。     

矮象草天然色素的研究

探讨了不同加工方法、不同贮存条件及不同贮存时间对矮象草天然色素含量的影响.试验结果表明:矮象草叶粉含有较丰富的天然色素.经低温烘干处理后的叶黄素含量比高温烘干处理的高;无氧贮存比有氧贮存叶黄素含量高,损失率低,且差异极显著(P<0.01);随着贮存时间的延长,叶黄素的含量有所下降.     

美洲狼尾草与象草杂交种生产的花期相遇及积温稳定性研究

通过分期短日处理和分期播种的方法，研究了美洲狼尾草与象草杂交种生产中双亲的光温特性，探讨杂交制种适宜花期的选择。试验结果表明：1．象草N51短日处理至抽穗期的积温值在年度间及年内的差异均较大。而处理至抽穗的天数较稳定为36．7±4．5天。2．美洲狼尾草不育系Tift23A为喜温短日作物，由于年度间气候差异表现为不同年份播种至抽穗的天数差异极大，可达20天以上。积温值年度间及年内差异也极大。3．象草的有效下限温度为13．6℃，美洲狼尾草不育系Tift23A约为14．8℃。4．杂交制种的适宜花期为8月下旬，即美洲狼尾草不育系Tift23A在6月1日、10日分期播种，而象草N51在7月15日进行短日处理，可实现花期相遇。     

不同种植密度及刈割次数对杂交狼尾草营养价值的影响

2009年4～11月在河北省大名县采用大田试验播种杂交狼尾草（Pennisetum americanum×P.purpureum）种茎,研究不同种植密度（6 944,13 889,27 778株/hm2）不同刈割茬数后其饲用价值的变化,为杂交狼尾草在生产实践中发挥较大的饲用价值提供理论依据。结果表明：粗蛋白含量随密度的...     

德宏象草不同生育时期营养成分研究

 德宏象草(Pennisetum purpurcum Schumach),在云南德宏分布广泛。营养分析结果说明,在生长的同一时期,该种的粗蛋白、粗脂肪含量高于王草,粗纤维含量低于王草,粗灰分与王草相当,说明在相同生长阶段,德宏象草的质量优于王草。     

41%异丙草-莠悬乳剂防除狼尾草田杂草效果初报

采用田间小区试验方法,研究了41%异丙草-莠悬乳剂对夏播狼尾草田杂草的防除效果。结果表明,41%异丙草-莠悬乳剂可有效防除狼尾草田的马唐、马齿苋和反枝苋等杂草,但对狼尾草的生长有一定不利影响。在考虑降低成本和保证饲草安全前提下,于狼尾草播种出苗后5d,用41%异丙草-莠悬乳剂2.250L/hm2,兑水稀释后均匀喷雾于地表面,可收到较好的除草效果。     

象草根部剑属线虫种类鉴定

 本文报道广州郊区象草根部发现的4种剑属线虫:移去剑线虫Xiphinema elongatum、摹仿剑线虫X.imitator、标明剑线虫X.insigne和根剑线虫X.radicicola.分别记述了它们的形态测量数据、鉴定特征、分布及其密度.     

巨菌草在冀中南地区的引种试验

[目的]缓解北方地区粮草争地矛盾。[方法]2014~2015年在冀中南地区进行巨菌草引种试验,探索巨菌草在我国北方地区的适宜种植管理模式。[结果]当巨菌草株高在1.2 m左右时,巨菌草叶风干样中粗蛋白含量达17.40%,茎风干样中粗蛋白含量为16.65%;当巨菌草株高在2.0 m左右时,巨菌草叶粗蛋白含量为16.18%,茎粗蛋白含量为12.17%。巨菌草在冀中南地区的产量为150~255 t/hm2。当巨菌草的留茬高度为5~10 cm时,最有利于巨菌草的再生。[结论]该研究可为巨菌草在北方地区的推广种植奠定基础。     

Genetic variation for Mg tissue concentration in pearl millet lines grown under Mg stress conditions

Efficient nutrient utilization by plants is extremely important in developing countries and is becoming more important in the developed countries as the costs of fertilizers are increasing. Pearl millet is a world food and forage crop usually grown on droughty soils low in nutrients. Eighty‐five genetically diverse pearl millet, Pennisetum glaucum (L.) R. Br. lines were grown in low Mg and K sand for three weeks to screen for efficient Mg uptake. Magnesium free Hoagland's solution at one‐fourth strength was used to water the plants as needed. Forage produced was clipped, dried, ground, ashed, and analyzed for Mg and K content. A 2‐fold difference for Mg concentration in the forage existed among the lines. The data indicated that a low [K]/[Mg] ratio in the plant was indicative of a Mg efficient genotype. The data also suggest that caution should be used in making general nutrient recommendations based on tissue or soil tests without knowing the nutrient requirement of the cultivar.