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贵州南部山地黄壤侈ＰＨ牧地施石灰可调节土壤ＰＨ，减少铁，铝、锰毒害，增加阳离子的交换量，减少钾淋失。同时施石灰还能影响土壤与植物的Ｋ／（Ｃａ＋Ｍｇ）比，在石灰与磷施用时应考虑石灰产生的逆效应 相似文献
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紫花苜蓿是豆科苜蓿属多年生草本植物 ,因其蛋白质含量高 ,氨基酸组分齐全 ,产量高 ,适应性广 ,又有很好的水土保持能力而著称。在苜蓿生产种的植当年要抓好“三关” :1 播前整地关首先 ,选择适宜的地块。紫花苜蓿对土壤要求并不严格 ,一般土壤均可种植 ,并有良好的改良土壤能力。其最适宜种植在中性或微碱性的土壤 ,适宜 ｐＨ值 6～ 8。在酸性士壤上种植需提前 1个月施用石灰 (磷石灰 )进行土壤改良 ,其施用量应根据土壤ｐＨ值高低而定。当 ｐＨ值 6～ 7,用量 75～ 15 0ｋｇ/ｈｍ2 ;ｐＨ值 6 ,用量 15 0～ 30 0ｋｇ/ｈｍ2 。施用石灰不仅… 相似文献
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草类植物耐铝性的研究进展 总被引：3，自引：2，他引：1
酸土在全世界热带、亚热带及温带地区广泛存在,酸雨的频繁沉降,加速了土壤酸化。酸性土壤中铝毒害是植物生长发育的主要限制因子。笔者综述了国内外关于铝毒害对草类植物生长发育的影响、草类植物耐铝机理以及草类植物耐铝性遗传育种的研究进展。最后分析了目前草类植物耐铝性研究存在的问题,并对草类植物耐铝性研究前景进行展望。 相似文献
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土壤盐碱化对羊草草地植物多样性的影响 总被引：10，自引：1，他引：9
从群落物种丰富度，均匀度和多样性三个测度水平，采用八个指数和Ｚａｈｌ的大折刀法统计处理，探讨了松嫩平原羊草草地次生盐碱化梯度植物多样性的变化，结果表明，随着土壤盐碱化的加重，群落植物多样性单调衰减，并与土壤ｐＨ值和电导率呈显著指数负相关，与土壤水分呈指数正相关；其植物多样性的演替序列是：羊草－杂类草群落〉羊草群落〉羊草－星星草群落〉星星草群落〉朝鲜碱茅群落〉角碱蓬群落，结果与次生盐碱化演替序列一致 相似文献
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1病因分析
土壤高钼可使生长的牧草钼含量过高，动物采食后引起钼中毒，见于腐植土和泥炭土。另外，植物中的钼含量还与土壤的酸碱度有关，碱性土壤中可溶性钼较多，容易被植物吸收，在含钼较低的碱性土壤上生长的植物钼含量也较高，而在强酸性富钼土壤上生长的牧草，其钼含量则较低。应用过量钼肥及石灰可增加植物对钼的吸收，动物容易发生与高钼有关的铜缺乏。 相似文献
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对松嫩草地不同生长时期的６种牧草的可溶性糖，粗脂肪，纤维素含量及其相应生长地土壤理化因子进行了研究，结果表明土壤的有机含量，全氮含量的提高有利于植物养分含量的积累，而ｐＨ的提高和Ｎａ＾＋和ＨＣＯ＾－３含量的增加则对植物养分含量的积累有抑制作用。但各种土壤理化因子对不同植物养分积累的作用是不同的，鹅茸萎菱菜的生长土地壤比较肥活，土壤理化因子以其养分积累影响不大，土壤Ｋ＾＋含量对星星草可溶性糖的积累起 相似文献
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河套灌区盐渍化人工草地土壤含水量,含盐量及pH变化规律 总被引：2，自引：0，他引：2
对河套地区盐碱荒地，弃耕地种植耐盐碱优良牧草后的土壤含盐量、含水量、ｐＨ变化规律，对土壤含水量，含盐量、ｐＨ相互变化关系及春季，秋季土壤含盐量、ｐＨ变化规律在连续数年进行了分析测定，在大量分析数据基础上，总结探讨了种草对盐碱地土壤含盐量，ＰＨ的影响。 相似文献
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紫花苜蓿(Medieigo saliva L)是一种营养价值高、适口性好、各类畜禽都喜食的优质牧草,有“牧草之王”之称。紫花苜蓿喜温暖、半湿润半干旱的条件,适宜在疏松的沙质中性土壤生长。我国南方地区的土壤多呈酸性,适合在北方生长的紫花苜蓿品种在南方往往不能正常生长,这主要是因为酸性土壤中的铝离子毒害限制了作物的生长。当土壤呈中性或碱性时,铝以硅酸盐和氧化铝形式存在,对植物无毒害;而当土壤呈酸性时,铝以离子形式存在,抑制植物根系生长,从而使植物出现干旱和营养缺乏的症状,导致植物减产。 相似文献
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蜂蜜中淀粉酶活性值（酶值ＤＮ）是评定蜂蜜质量的一项重要指标,新鲜的蜂蜜其酶值较高,营养好。本文在传统检测方法,度管碘反应目测法和分光光度比色法的基础上,结合两者的优点,采用标准参考比色板法,该方法具有方便、易行、快速可靠等优点。 相似文献
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神经生长因子对神经元作用的研究进展 总被引：5，自引：0，他引：5
神经生长因子(NGF)是最早被发现的一种神经营养因子。NGF是对神经元的存活、生长发育、分化、再生和功能维持起调控作用的物质。早期应用组织细胞培养手段证实了NGF对交感、感觉及中枢胆碱能神经元具有营养作用,能维持其存活并诱导其突起生长。20世纪80年代以来,随着在动物体内神经损伤与再生模型制备技术的发展,NGF对神经再生及功能恢复作用的研究日趋深入,NGF的效应神经元范围也在扩大,有望为神经系统疾病提供有效的治疗手段。 相似文献
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动物胃肠微生态及其调控 总被引：1，自引：0，他引：1
动物胃肠微生态是由胃肠道的微生物区系所组成的一个微生态系统，胃肠微生态在营养物质的消化、吸收和提高动物免疫力以及生产性能等方面起着重要的作用。本文介绍了动物胃肠微生态环境中微生物的组成胃肠微生态的调控，阐述了胃肠微生态环境中各种微生物之间、微生物与宿主之间的相互作用关系。 相似文献
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随着科学的不断发展,人们对蜂产品的研究也越来越深入,有关蜂产品抗衰老、抗动脉硬化、抗疲劳、抗肿瘤、抗感染的文章报道有很多。人们从实验室的实验分析到大批人群的,临床试验都证明蜂产品确实能对我们人类的健康起作用。作为传统营养品的蜂产品,在整个大食品行业里的分量越来越轻,整个行业还较为散乱,市场的集中度很低、缺少强势领导品牌。 相似文献
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洋麻在甘肃引种区域性试验研究 总被引：1，自引：1，他引：0
洋麻Hibiscus cannabinus是近2年从美国引入甘肃的新型牧草,同时也是一种新型的工业原料,先后在甘肃省11个县(市)试种成功.对其生物学特性、栽培技术进行了广泛的区域性试验研究,同时对洋麻各生育期的营养价值及利用方向进行了有益的探索,结果表明其各种性状表现良好,在甘肃河西地区气候条件下具有较强的适应性. 相似文献
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Effects of enzyme supplementation of a total mixed ration on microbial fermentation in continuous culture, maintained at high and low pH 总被引：6，自引：0，他引：6
A dual-flow continuous culture system was used to investigate the effects of pH and addition of an enzyme mixture to a total mixed ration (TMR) on fermentation, nutrient digestion, and microbial protein synthesis. A 4 x 4 Latin square design with a factorial arrangement of treatments was used, with four 9-d periods consisting of 6 d for adaptation and 3 d for measurements. Treatments were as follows: 1) high pH with control TMR, 2) high pH with TMR treated with enzyme, 3) low pH with control TMR, and 4) low pH with TMR treated with enzyme. Ranges of pH were 6.0 to 6.6 and 5.4 to 6.0 for high and low, respectively. Fermenters were fed twice daily a TMR consisting of 30% alfalfa hay, 30% corn silage, and 40% rolled corn (DM basis). The silage was milled fresh and the TMR was fed to the fermenters in fresh form (64% DM). The enzyme mixture was a commercial product of almost exclusive protease activity; it was applied daily to the fresh TMR and stored at 4 degrees C for at least 12 h before feeding. Degradability of OM, NDF, ADF, and cellulose was decreased (P < 0.05) by low pH. Hemicellulose and protein degradation were not affected by pH. Enzyme addition increased (P < 0.01) NDF degradability (by 43% and 25% at high and low pH, respectively), largely as a result of an increase in hemicellulose degradation (by 79% and 51% at high and low pH, respectively). This improvement was supported by an increase (P < 0.05) in the xylanase and cellulase activities in the liquid phase of the fermenter contents. Total VFA were decreased (P < 0.05) by low pH, but were not affected by enzyme addition. Total bacterial numbers were increased (P < 0.03) at low pH and tended (P < 0.13) to increase with enzyme addition. Cellulolytic bacteria in effluent fluid were decreased (P < 0.02) at low pH but were unaffected by enzyme addition. Despite a large increase (P < 0.001) in protease activity, protein degradation was only numerically increased by enzyme addition. Microbial protein synthesis was higher (P < 0.10) at high pH but was not affected by enzyme addition. Methane production, expressed as a proportion of total gases, was decreased (P < 0.001) at low pH but was not affected by enzyme addition. It is concluded that it is possible to adapt the continuous culture system to use fresh feeds instead of dried feeds. Overall, the results indicate that the enzyme product used in this study has a potential to increase fiber degradability without increasing methane production. 相似文献
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不同阶段体重与产蛋性状遗传相关分析 总被引：2，自引：0，他引：2
对白来航蛋鸡各阶段体得发育与主要产蛋性状的遗传相关分析表明，６周体重与３００天平均蛋重的跗个关为０．８４１（Ｐ〈０．０１）、与７２周入舍鸡产蛋数的遗传相关为０．６２７（Ｐ〈０．０１）。６周龄前后是培育壮体格、发达内脏的后备母鸡的重要时期。 相似文献
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Inchaisri Chaidate Chanpongsang Somchai Noordhuizen Jos Hogeveen Henk 《Animal Science Journal》2014,85(9):861-867
Subacute ruminal acidosis in dairy cows occurs when ruminal pH is below about 5.5. However, the exact threshold level of ruminal pH affecting cow health is still in debate. This investigation was carried out in 505 cows within 31 farms. The postpartum disorders, including dystocia, retained placenta, anestrus, cystic ovary, metritis, clinical mastitis and lameness, were analyzed. Ruminal pH, serum beta‐hydroxy butyrate (SBHB), serum urea nitrogen and body condition score (BCS) were measured once during the 3 to 6 weeks postpartum, while BCS was determined once more at 1 week before calving. Ruminal pH was determinded by ruminocentesis technique. The ruminal pH was evaluated to study the association with BCS, SBHB and postpartum disorders using linear regression in a generalized linear mixed model with farm as a random effect. The results show that low ruminal pH was associated with dystocia, metritis and lameness. Moreover, a low ruminal pH can be found in cows with a high loss of BCS after calving and also in cows with low SBHB postpartum. These findings confirmed the feasibility of the ruminocentesis technique and the association of low ruminal pH on various postpartum disorders at the individual cow level. However, the consequences of low ruminal pH on dairy cow health still needs more exploration for a better understanding of the physiological mechanisms. 相似文献
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Yuya TSURUTA Shusaku T. SHIBUTANI Rie WATANABE Hiroyuki IWATA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):153-156
The effect of environmental acidification on Ibaraki virus (IBAV) infection was tested
using endosomal inhibitory chemicals and low pH treatment. Treatment of target cells with
endosomal inhibitors significantly decreased the progeny virus production. IBAV outer
capsid proteins, VP5 and VP2, were removed from virion when purified IBAV was exposed to
low pH environment. Further experiment showed that the exposure to low pH buffer
facilitated IBAV infection when the cellular endosomal pathway was impaired by bafilomycin
A1. Results obtained in this study suggest that acidic environment is essential to
initiate IBAV infection. 相似文献
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Yoshinaga K 《The Journal of reproduction and development》2012,58(2):196-203
The process of blastocyst implantation is a series of interactions between the blastocyst and maternal tissues. The purpose of this process is (1) to provide nourishment to the embryo for developmental growth in appropriate physiological and endocrinological environment until a placenta is established, and (2) to protect the (semi-)allogeneic embryo from any attacks from the maternal immune system. To facilitate successful implantation, therefore, these two aspects of the embryonic demand must be satisfied in the embryo-maternal interface throughout the entire process of implantation. The first concept I present in this paper is that blastocyst implantation essential factors (BIEFs) have dual functions: one, for structural and functional modification of the endometrium to accommodate the developing embryo and provide nourishment and suitable environment for its development, and the other, for modulation, directly or indirectly, of the maternal immune system to prevent attacks by the maternal immune system. The second concept is that BIEFs convert the endometrium (or uterus) from an immunologically non-privileged site to a privileged site. This endometrial (uterine) conversion is the immunological aspect of the blastocyst implantation process. When the endometrium has become receptive for blastocyst implantation, it signifies that the immunological conversion of the endometrium by BIEFs has been sufficiently attained to let the embryo start contacting maternal tissues. During the early stages of placentation, as the trophoblast cells differentiate and make their way to the maternal blood vessels to establish the placenta, BIEFs continuously provide nourishment and immunological protection to the developing embryo. The immunological protection of the embryo/fetus from potential attacks by the maternal immune system appears to reach a peak at the time of establishment of the placenta. Thus, clarification of the roles of BIEFs in both the physiological/endocrinological aspect as well as the immunological aspect is essential for understanding the biological process of implantation. 相似文献