不同钴水平对北京鸭生产性能和血液生理生化指标的影响

试验选用11日龄北京鸭420只,研究日粮中添加不同水平的钴(0、0.25、0.5、1.0、2.0、4.0mg/kg)对北京鸭生产性能及相关血液生理生化指标的影响。结果表明:日粮中添加钴可显著提高北京鸭的血液红细胞数、红细胞压积(P<0.10),血浆总蛋白、白蛋白及球蛋白含量(P<0.01),红细胞C3b受体花环率(P<0.01)、血浆中维生素B1(2P<0.01)、钴含量(P<0.01)和肝脏钴含量(P<0.01),而且随日粮中钴添加量的增加,红细胞数、红细胞压积,血浆总蛋白、白蛋白、球蛋白含量,血浆维生素B12、钴和肝脏钴含量均呈二次曲线关系(P<0.01),而血浆铁含量线性降低(P<0.01),红细胞C3b受体花环率则线性提高(P<0.01)。因此,北京鸭日粮中钴的适宜添加量为1.8～2.8mg/kg。     

Branchial cobalt uptake in the carp, Cyprinus carpio: Effect of calcium channelblockers and calcium injection

Using tracer-uptake studies we investigated whether the branchial uptakeof cobalt occurs via selective, inhibitable, calcium uptake routes.Modulation of the calcium transport system was performed using generalcalcium channel blockers (Cd²⁺, La³⁺,Mg²⁺), a voltage-dependent calcium channel blocker (diltiazem)and an intraperitoneal CaCl2 injection. Adding Cd²⁺ orMg²⁺ to thewater or injecting the fish with theCa²⁺-solution resulted in decreased Co²⁺ andCa²⁺ uptake rates. Addition of La³⁺ reducedCa²⁺ and Co²⁺ uptake rates except forCo²⁺ uptake in the gills. Diltiazem displayed only aninconsistent, concentration-independent blocking of the uptake of bothCo²⁺ and Ca²⁺. All inhibitors which inhibitCa²⁺ uptake also inhibit Co²⁺ uptake. However, aclear difference in the degree of inhibition of uptake of both elements isobserved. Two possible explanations are suggested (1) Co²⁺ andCa²⁺ are both transported through the gills via the sametransport system or (2) the calcium transport system is not the only systeminvolved in the transport of Co²⁺.     

^60Coγ射线对水仙鳞茎的影响

＾６０Ｃｏγ射线能显著降低水仙鲜重的增加，抑制根，叶生长，但对根粗，叶片宽及工影响甚小。叶片维管束细胞受辐射损伤较大，用２－６Ｇｙ剂量处理均能提高水仙花单花寿命，延迟始花期，其根系长度与鲜重增量和叶长间呈显著线性正相关。     

施钴对冬小麦产量品质的影响

在潮土上采用田间小区试验,研究了钴元素对小麦产量和品质的影响。结果表明:施用适量的钴可以显著提高冬小麦的产量,改善冬小麦的品质。各施钴处理较对照增产7.4%～20.3%。施钴量在1.05kg.hm2以内,随着施钴量的增加,增产效应提高,当施钴量超过1.05kg.hm2时,随着施钴量的增加,冬小麦的产量增加,但增产效应下降。各施钴处理子粒蛋白质含量与蛋白质产量均有不同程度的提高,以Co2处理最高。此外,低浓度的钴(施钴量0.45～0.75kg.hm2)可以提高冬小麦子粒面粉的沉降值、总评价值和湿、干面筋含量,而高浓度的钴(施钴量大于1.35kg.hm2)则降低冬小麦子粒面粉沉降值、总评价值和湿、干面筋含量。土壤有效钴含量与施钴量呈极显著正相关,小麦籽粒中钴含量与施钴量呈显著正相关,地下部的钴含量显著大于地上部。     

Trace Metal Contamination During Grinding of Plant Samples

Inductively coupled plasma-mass spectroscopic (ICP-MS) analysis of leaves from 22 cabbage crops in the Sa P? and B?c Hà districts of Láo Cai Province, North-Western Vi?t Nam, revealed unexpectedly high concentrations of chromium (Cr) and nickel (Ni). The concentrations were strongly linearly related (r² = 0.94), indicating sample contamination during grinding through a stainless-steel hammer mill. We tested this hypothesis in two ways. First, brown rice ground through the same mill was contaminated not only by Cr and Ni, but also cobalt (Co), iron (Fe) and molybdenum (Mo). Second, scanning electron microscopy/energy dispersive analysis of x-rays (SEM/EDS) of the ground samples revealed small fragments with co-located Fe, Cr and Ni, consistent with stainless steel wear fragments. Other grinders may perform differently and we suggest that quality assurance protocols for trace metal analysis of plants should include testing for grinder wear metals. Lastly, brown rice appears to be convenient for investigating contamination of plant tissues during grinding.     

钴的动物营养学功能

钴作为动物体内一种必需的微量元素,虽然动物对其需要量并不大,但钴对动物的造血机能、免疫机能、生长发育及繁殖,特别是对反刍动物瘤胃微生物合成VB12等起着重要的作用,钴与其他微量元素合用会有更加明显的效果。钴缺乏会引起动物生产性能的下降,易给畜牧业带来很大经济损失,因此,随着科学研究的深入,钴的重要营养作用也逐渐被发现并受到人们的重视。就钴的生物学作用、钴的营养学作用机制、钴缺乏的发病机制、与其他营养素之间的关系及其在动物营养中的重要作用进行了阐述。     

高亲和性镍钴转运系统的研究进展

镍作为生物体必需的微量元素,存在于一些与能量和氮代谢相关的金属酶中。钴主要参与维生素B12的合成,再进一步被含维生素B12的酶利用。由于环境中只存在微量的镍和钴,生物体为满足其对镍和钴的需求,形成了高亲和性的镍钴吸收系统。目前对微生物的研究中发现,高亲和性镍和钴的吸收主要依赖于ABC(ATP-binding cassette)转运家族和其他一些次级转运蛋白(secondary transport-ers)。文中对这两方面的研究进展进行了综述,并对其末来研究发展进行了展望。     

Cobalt reduces the Δ⁹-desaturase index of sow milk

The main objective of this study was to examine if cobalt (Co) reduces Δ(9) -desaturase indices in milk and blood lipids in sows. The experimental design consisted of a repeated measurement consisting of a pre-treatment period of a minimum of 9 days, a treatment period of 5 days and a post-treatment period of 6 days. Experimental animals consisted of 10 lactating sows; five sows had an intramuscular injection of 59 mg Co diluted in 5 ml 0.9% saline solution twice a day, whereas the other five had an intramuscular injection of 5 ml 0.9% saline solution twice a day as a control. Milk Δ(9) -desaturase indices for cis-9 18:1, cis-9 16:1 and cis-9 14:1 were significantly reduced (p < 0.0001) as a result of the Co-treatment, contrasting with the plasma Δ(9) -desaturase indices, which were unaffected. Potential mechanisms explaining how Co might reduce milk Δ(9) -desaturase indices are discussed. Moreover, the toxicological level of Co and potential implications of using Co-ethylenediaminetetraacetic acid as a liquid marker in digestibility experiments are addressed.     

SOIL APPLIED COBALT AND COPPER ALTER THE RHIZOBIUM SYMBIOSIS AND GROWTH STATUS OF LABLAB PURPUREUS (L.) SWEET

A pot experiment was performed to investigate the effect of cobalt (Co) and copper (Cu) nutrition on nodulation, nodule activity and growth of Lablab purpureus plants growing in sandy clay loam soil collected from Toshka region in south of Egypt. The pots were given nutrient solution only once with addition of increasing levels of cobalt and copper (50, 100, 150 and 200 μg) as cobalt or copper sulfate solution. The present study has provided a new insight into the effect of cobalt and copper on nodulation and nodule physiology of Lablab purpureus (L.) Sweet (kashrangeeg) that has not yet been examined. Thus, the present work suggest that Co and Cu application is essential for the enhancement of nodulation, nodule activity and growth of Lablab purpureus plants growing in sandy clay loam soil deficient for theses microelements.