Influences of different dietary contents of macrominerals on the availability of trace elements in horses

In this study, influences of a reduced macromineral intake on the trace element metabolism in horses at maintenance were investigated. Background of this study is the revised recommendation on the macromineral supply for horses (GfE 2014 ). Balance studies on three adult pony geldings with body weights of 405 / 348 / 384 kg were performed to obtain data on apparent digestibility (aD), retention and serum concentrations of different trace elements (Cu, Zn, Se) at different dietary macromineral levels. A mineral supplement or a complementary feed—with a reduced macromineral content—was added to a hay‐based diet (daily 5.5 kg hay per animal, split in three servings a day), beside distilled water was offered. The diets were offered one after the other in a way that all ponies had the same sequence of treatments. The native macromineral contents of the daily offered amount of hay already surpassed the new recommendations whereas dietary trace elements needed to be supplemented. There were no statistically significant differences (p ≤ .05) concerning the aD of copper, zinc and selenium comparing the diets with and without macromineral supplementation. Serum levels of these three trace elements were not affected by the different macromineral content of the diet. Results of this study, based on a 22‐day feeding period for each treatment, indicate that a macromineral supplementation of a hay‐based diet for adult horses at maintenance was not necessary. However, no negative effects of added macrominerals on the trace element metabolism occurred in this study.     

饲粮铜水平对冬毛期雌性蓝狐生长性能、营养物质消化率、血清生化指标及毛皮品质的影响

本试验旨在研究饲粮铜水平对冬毛期雌性蓝狐生长性能、营养物质消化率、血清生化指标及毛皮品质的影响。试验选取115日龄左右的健康雌性蓝狐50只,随机分成5组,每组10个重复,每个重复1只。以五水硫酸铜(Cu SO_4·5H_2O)为铜源,在基础饲粮中分别添加0、12.22、32.22、72.22、152.22 mg/kg的铜配成5种试验饲粮,5种试验饲粮铜水平分别为7.78(Ⅰ组,作为对照组)、20(Ⅱ组)、40(Ⅲ组)、80(Ⅳ组)、160 mg/kg(Ⅴ组)。预试期为7 d,正试期为60 d。结果表明:1)Ⅲ、Ⅳ和Ⅴ组蓝狐的平均日增重显著高于对照组(P0.05),料重比显著低于对照组(P0.05);各组蓝狐的终末体重及平均日采食量差异不显著(P0.05)。2)各组蓝狐的干物质消化率、蛋白质消化率及氮沉积差异不显著(P0.05);Ⅲ、Ⅳ组蓝狐的脂肪消化率显著高于对照组(P0.05),其他各组间差异不显著(P0.05);铜排出量随着饲粮铜水平的升高极显著的增加(P0.01)。3)Ⅴ组蓝狐血清总蛋白和白蛋白含量显著高于对照组和Ⅱ组(P0.05);Ⅴ组蓝狐血清尿素氮含量显著高于Ⅱ组(P0.05);各组蓝狐血清铜蓝蛋白活性差异不显著(P0.05),Ⅳ组蓝狐血清铜锌超氧化物歧化酶活性显著高于对照组及Ⅱ和Ⅲ组(P0.05)。4)Ⅴ组蓝狐肝脏铜含量显著高于对照组(P0.05),血清铜、锌、铁含量各组间差异不显著(P0.05)。5)饲粮铜水平并未显著影响蓝狐的体长和干皮长(P0.05);Ⅲ和Ⅴ组蓝狐针毛长和绒毛长显著大于Ⅱ和Ⅳ组(P0.05);Ⅴ组蓝狐皮张颜色显著深于对照组(P0.05)。由此可见,在饲粮中添加32.22 mg/kg铜即铜水平为40.00 mg/kg时,冬毛期雌性蓝狐可获得较好的生长性能、营养物质消化率及毛皮品质,同时铜的排放量较低。     

Changes in liver copper concentration of thoroughbred foals from birth to 160 days of age and the effect of prenatal copper supplementation of their dams

OBJECTIVES: To monitor the change in liver copper concentration of Thoroughbred foals from birth to 160 days of age and to determine the effects of supplementation by two injections of copper edetate given to dams in late gestation on the liver copper concentration of their foals at birth. PROCEDURE: Ten mares pregnant to the same stallion were randomised into two groups on the basis of age, liver copper concentration and expected foaling date. The treatment group mares were given 100 mg and 250 mg copper edetate intramuscularly during the ninth and tenth months of gestation respectively. Foals had liver biopsies taken weekly in the first month of life, then monthly for four months. Foals were euthanased at 160 days of age; liver samples were taken and the copper concentrations were determined. RESULTS: Two distinct patterns of age dependent decline in liver copper concentration were evident. The mean (+/- SD) liver copper concentration of the foals was high at birth (374 +/- 130 mg/kg DM), and for seven it declined to adult values by 160 days of age (21 +/- 6 mg/kg DM). In three foals the decline was at a slower rate than in the other seven and at 160 days of age the mean concentration was 162 +/- 32 mg/kg DM. Repeated measures analysis showed significant differences between each biopsy (P < 0.01) and between 'normal' and 'accumulator' foals (P < 0.002). Copper injections given to mares in late pregnancy had no effect on the liver copper concentration of foals at birth. CONCLUSIONS: The significance of the two patterns of age dependant decline in liver copper concentration is unknown. Parenteral copper supplementation of the dam in late gestation had no effect on the liver copper concentration of the foal at birth.     

Nucleotide Sequence and Organization of Copper Resistance Genes from Pseudomonas syringae pv. actinidiae

Copper-containing bactericides have been used to control bacterial canker of kiwifruit, caused by Pseudomonas syringae pv. actinidiae. However, the efficacy of copper has been reduced by the occurrence of copper-resistant strains. Analysis of the DNA sequence of a cluster region containing the copper-resistance genes from P. syringae pv. actinidiae suggested the presence of three possible different systems for copper resistance: copper-trapping, copper-efflux and copper-transport systems. Transposon insertional inactivation analysis indicated that the copper-trapping system was essential for copper resistance.     

日粮锰对肉仔鸡组织器官锰、铜、锌沉积的影响

选用 1日龄艾维茵肉仔鸡 ,采用单因子多水平随机化试验设计 ,随机分成 6组 ,每组 3个重复 ,每个重复 8只鸡。在玉米 豆粕型基础日粮中分别添加锰 (MnSO4 ·H2 O) 0 ,40 ,80 ,1 2 0 ,1 60 ,2 0 0mg/kg ,研究日粮锰对肉仔鸡组织器官锰、铜、锌沉积的影响。结果表明 :在肉仔鸡日粮中添加 40 2 0 0mg/kg的锰 ,对胫骨锰、肝脏锰和肾脏锰的沉积有显著的影响 (P <0 0 5) ;日粮锰的添加对肝铜和肾铜沉积无明显影响 (P >0 0 5) ,但日粮锰添加量超过 1 2 0mg/kg时 ,能够减少胫骨铜的沉积 (P <0 0 5) ;对胫骨、肝和肾中锌的沉积无明显影响(P >0 0 5)。     

包头某铜厂周边土壤重金属分布特征及来源分析

通过测定包头某铜厂周边4方向不同水平距离及深度处64个土壤样品中Cu、Cd、Pb、Zn、Mn、Cr 6种重金属含量,探讨其空间分布特征及可能来源。结果表明,铜厂周边土壤中6种重金属均已呈现不同程度的富集,其中Cu、Cd、Pb污染普遍且严重,且Cu受人为活动干扰最为强烈。6种重金属含量分布主要取决于其所在位置距铜厂的水平距离和土层深度,其中:0~20 cm表层土壤中重金属含量随水平距离增加呈现先增大后减小的规律,Pb、Cr和Cu、Zn、Mn分别在100 m和300 m处达到峰值;在距铜厂不同水平距离的样品中,各重金属含量均随土层深度增加而减小,但相距50 m处减小缓慢,100 m、300 m处减小迅速。土壤重金属来源解析表明,铜厂周边土壤中Cr、Cd、Cu来自复合污染源,Pb、Zn的外源污染主要来自交通源,Mn主要来自自然源。     

Fractions of Copper in Soil and Their Contribution to Copper Availability in Rice–Wheat Cropping System under Long-Term Integrated Nutrient Management in an Acid Alfisol

Long-term effects of integrated application of organics and chemical fertilizers on transformation of copper (Cu) into various chemical pools and their availability under rice (Oryza sativa L.)–wheat (Triticum aestivum L.) cropping system were investigated in the ongoing long-term fertilizer experiment initiated in 1991 kharif season (May–October) at the research farm of Chaudhary Sarwan Kumar Himachal Pradesh Agricultural University on an acidic soil in the Western Himalayas of India. The continuous use of chemical fertilizers alone for 20 years brought about marked depletion in all forms of copper except organically bound Cu (Cu-PYR) compared to buffer plots. Integrated use of organics and chemical fertilizers gave higher content of Cu forms over chemically treated plots except Cu occluded by free oxides (Cu-OX). Residual Cu was the most dominant form of copper contributing about 67% of the total Cu. Soil solution and exchangeable Cu (Cu-CA) was the most important fraction of copper contributing toward DTPA (diethylene triamine pentaacetic acid) extractable Cu. Content of DTPA extractable Cu increased over control when chemical fertilizers were applied in conjunction with different organics, whereas DTPA Cu content declined over control with application of chemical fertilizers alone for the last 20 years.     

铜合金网衣在海水养殖中的应用研究进展

铜合金网衣在渔业工程领域特别是网箱和围栏网海水养殖中得到了广泛的应用,并取得良好效果。铜合金网衣具有"0"生物附着、高效低碳、健康环保等特点。本文结合国内外在海洋、环境和金属材料等领域对铜合金研究已取得的成果,探讨了铜合金网衣在海洋中的抗污、耐腐蚀机理;通过介绍几种铜合金网衣类型,描述了两种结构类型的铜合金网衣网箱的制作方法以及在网箱养殖应用中常见的问题,并分析了其结构、力学特性和抗风浪能力等作业性能的关系,对铜合金网衣网箱在渔业上的应用情况及研究进展进行了梳理,以期为铜合金网衣网箱的进一步研究和应用提供参考。     

日粮锌源和锌水平对断奶仔猪血清及组织铜、锌沉积的影响

探讨日粮锌源和锌水平对断奶仔猪血清及组织铜、锌沉积的影响.试验选用21日龄"杜×长×大"三元杂交的断奶仔猪40头,按体重和性别随机分成4组(Ⅰ～Ⅳ组),每组10头猪.分别饲喂添加氧化锌(以锌量计)Ⅰ组(对照组)100 mg/kg、Ⅱ组3 000 mg/kg和蛋氨酸锌(以锌量计)Ⅲ组100 mg/kg、Ⅳ组300 mg/...     

日粮添加高铜对幼龄水貂生长的影响

通过在幼龄水貂基础日粮中添加不同水平的铜探讨高铜日粮对水貂生长的影响.选取70只80日龄的健康水貂随机分成7组,每组10只,对照组水貂饲喂含铜5.98 mg/kg的基础日粮,6个试验组分别在基础日粮中添加210、220、240、250、260、310 mg/kg的铜,试验期60 d.饲养试验和生长速度测定分析结果表明：与对照组相比添加铜的1～4组对水貂的生长均有显著的促进作用,第4组水貂生长速度达到最大,第5组和第6组水貂生长速度减慢.由此可知：高铜日粮对幼龄水貂的生长有促进作用,日粮中添加250 mg/kg铜为幼龄水貂生长的最佳添加量,此时饲料中的总铜质量分数为255.98 mg/kg;日粮中添加过高剂量的铜会抑制水貂的生长.