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NaCl和Na2CO3对星星草生长及营养液中主要矿质元素存在状态的影响 总被引:9,自引:0,他引:9
星星草生长在0-600mmol/LNaCl和0-200mmol/LNa2CO3的盐胁迫下,测定了其生长状况及营养液中主要矿质离子的游离度、活度等。结果表明:相同Na^+活度下,Na2CO3对星星草的生长尤其是根生长的抑制作用明显大于NaCl。 相似文献
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NH_4Cl和NaHCO_3对肉用仔鸡慢性热应激的影响 总被引:6,自引:0,他引:6
320 羽1 周龄健康肉用雏鸡被随机分成4 组, 经1 周的适应后进行试验。组Ⅰ、组Ⅱ、组Ⅲ和组Ⅳ的日粮处理分别为: 基础日粮(B, 对照组) , B+ 0-5 % NaHCO3 , B+ 0-5 % NaHCO3 + 1 % NH4Cl 和B+ 1 % NH4Cl。试验为期5 周。研究日粮中添加NaHCO3 和NH4Cl 对慢性热应激肉用仔鸡的血液pH、CO2 分压(PCO2) 及生产性能的影响。结果表明: 在慢性热应激(23 ~35 ℃) 条件下, 肉用仔鸡未发生呼吸性碱中毒, 组Ⅱ的血液PCO2高于对照组( P< 0-01) , 增重比对照组多9-49 % ; 组Ⅲ血液pH 低于组Ⅰ和组Ⅱ( P < 0-01) , 血液的PCO2 高于组Ⅰ和组Ⅳ( P < 0-01) , 增重比对照组多8-19% 。组Ⅳ的血液pH 值极显著低于对照组( P < 0-01) , 比对照组少增重2-5 % 相似文献
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斑点叉尾生长需要的钙源为配制全价配合饲料,美国德克萨斯大学的研究人员对饲料中的钙源和不同含量对斑点叉尾(1.7g)生长的影响进行了研究。试验饲料中分别添加0.5%-2.0%的CaCO_3、2.0%的CaCl,·2H_2O、2.0%的CaHPO_4·2?.. 相似文献
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河套灌区盐渍化人工草地土壤盐分及养分动态变化规律探讨 总被引:4,自引:0,他引:4
对盐渍化人工草地土壤盐分离子(Cl-、SO2-4、CO2-3、HCO-3、Na+、K+、Mg2+、Ca2+)及土壤有机质、全氮、全磷等营养成分在0~30cm土层内的动态变化规律进行了连续分析测定。为进一步客观评价“生物治碱”功效提供了可靠依据。 相似文献
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野大麦种子萌发条件及抗逆性研究 总被引:26,自引:5,他引:21
对野大麦种子在不同温度和预处理萌发条件以及在盐(NaCl和Na2SO4)和干旱(聚乙二醇,分子量6000)胁迫下萌发能力的研究表明,野大麦种子的最适发芽温度是15/25℃变温,破除休眠的最佳方法是预先冷冻,野大麦种具有较高的耐盐性,对2种盐的耐盐顺序为NaCl〉Na2SO4;种子萌发期耐盐临界值为-1.34MPa(NaCl)和-1.13MPa(Na2SO4)高渗透性盐胁迫(≥-0.5MPa)下,胚 相似文献
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有报道指出,香牙蕉(AAA)植株缺钙时果实品质差且成熟时果皮开裂。也有试验证实对红江橙、荔枝等果树叶面喷钙及植物生长调节剂可减轻采前裂果现象。据此笔者于1997-1998年在对中山龙牙蕉裂果发生过程进行观察的同时,开展了田间喷钙及植物生长调节剂的防裂试验。 试验设8个处理:(1)0.5%CaCl2(氯化钙),(2)1%CaCl2,(3)1.5%CaCl2,(4)0.5%CaCl2+GA3(赤霉素)10mg/l,(5)0.5%CaCl2+2,4-D10mg/l,(6)0.5%CaCl2+ 2,4-D… 相似文献
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黄河三角洲地区苜蓿生态适应性研究 总被引:17,自引:5,他引:12
本文研究了不同苜蓿品种在黄河三角洲地区的生态适应性。结果表明,该地区紫花苜蓿的根系主要分布于0 ̄30cm土层,因受到潜水水位及盐分的影响,主根被伤害从而诱导侧根发育是苜蓿适应该地区的主要特征之一。根系对降低表层土壤含盐量及有机质和全氮含量的增加有明显效果。当地地方品种无棣苜蓿对降低土壤离子含量的程度各异,对降低CO3^2-、Cl^-、SO4^2-和Na^+含量的作用明显,对HCO3^-、Ca^2+ 相似文献
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钾素营养对星星草幼苗抗碱性的影响 总被引:5,自引:1,他引:4
通过不同水平钾素营养培养星星草幼苗,研究钾素营养对星星草幼苗抗碱性的影响。结果表明:在2.0%Na2CO3胁迫下,星星草幼苗钾素营养的最适浓度为1.35mmolL^-1KCl,此条件不仅对株高、干重和鲜重的增长有促进作用,而且受害程度最小,对Na2CO3胁迫的缓解作用最强,在一定程度上可提高星星草幼苗对Na2CO3胁迫的抗性。 相似文献
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鲁梅克斯K—1杂交酸模耐盐性的初步研究 总被引:3,自引:0,他引:3
对鲁梅克斯K-1杂交酸模干种子,种子萌发,苗期及成株的耐盐性进行了研究,通过测定在不同Na2SO4和Na2CO3盐浓度胁迫下其膜透性,发芽率,根冠比,游离脯氨酸,丙二醛诸生理指标,对其耐盐性作出综合评判。研究结果表明,鲁梅克斯K-1杂交酸模对Na2SO4的耐盐性为0.8% ̄1.0%,对Na2CO3为0.2% ̄0.3%,高于此浓度表现为Na2SO4、Na2CO3盐胁迫的症状。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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以国际标准强毒R株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离MG,并收集感染鸡所产蛋分离MG。结果表明,人工感染48小时后上、下呼吸道及肺已被全面感染,96小时气囊已被感染,120小时输卵管已能分离到MG,卵巢始终分离不到MG。人工感染鸡自144小时便能在其所产蛋中分离出MG。药物治疗能在72小时内消除感染,油乳剂苗则需24天后逐渐降低蛋内MG分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内MG,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献