羟基蛋氨酸铜中铜含量的测定

分别用PAN、二甲酚橙、紫脲酸铵作为指示剂,研究了EDTA配位滴定法测定羟基蛋氨酸铜螯合物中铜含量的方法,标准偏差均小于0.2%,相对标准偏差小于0.6%。结果表明,EDTA配位滴定法测定羟基蛋氨酸铜中铜含量,操作过程简单、方便,分析结果重现性好、准确度高,且三种指示剂均可用于铜的测定,其中紫脲酸铵最好,终点变色敏锐。本法可用于不同工艺所合成的羟基蛋氨酸铜中铜含量的测定。     

Copper status of ewes fed increasing amounts of copper from copper sulfate or copper proteinate

The Cu status of mature, crossbred ewes fed two sources (CuSO4 vs. Cu proteinate) and three levels (10, 20, or 30 mg/kg) of dietary Cu was determined in a 73-d feeding trial. Ewes (n = 30) were fed a basal diet containing rice meal feed, cottonseed hulls, cottonseed meal, meat and bone meal, cracked corn, and vitamin-mineral supplements at 2.5% of BW to meet NRC requirements for protein, energy, macrominerals, and microminerals, excluding Cu. The basal diet contained 5 mg/kg Cu, 113 mg/kg Fe, .1 mg/kg Mo, and .17% S. Copper sulfate or Cu proteinate was added to the basal diet to supply 10, 20, or 30 mg/kg of dietary copper in a 2x3 factorial arrangement of treatments. Ewes were housed in 3.7- x 9.1-m pens in an open-sided barn. Blood samples were collected on d 28 and 73. Ewes were slaughtered on d 74, and liver and other tissues were collected to determine Cu concentrations. An interaction (P = .08) occurred between source and level for liver Cu. The interaction existed due to an increase in liver Cu concentrations when ewes were fed increasing dietary Cu from CuSO4 but not when fed Cu proteinate diets. There was no source x level interaction (P>.10) for the blood constituents measured. On d 73, plasma ceruloplasmin activity was greater (P<.05) in ewes fed Cu proteinate than in those fed CuSO4 (33.1 vs. 26.8 microM x min(-1) x L(-1)). Increasing the concentration of dietary Cu did not affect (P>.10) plasma ceruloplasmin. Packed cell volume (PCV), red blood cell count (RBC), white blood cell count, whole blood hemoglobin (wHb), plasma hemoglobin, and plasma Cu were similar between sources of Cu. Ewes fed 20 mg/kg Cu had lower (P<.05) PCV, RBC, and wHb than those fed 10 or 30 mg/kg Cu diets. Feeding up to 30 mg/kg Cu from these sources did not cause an observable Cu toxicity during the 73-d period.     

Predicting copper status in beef cattle using serum copper concentrations

Copper deficiency is common in pasture-fed cattle in New Zealand⁽¹⁾. In general, the diagnosis of copper deficiency in a herd of cattle is based on a combination of history, examination of animals, examination of the environment, chemical analysis of blood, liver or pasture, and treatment response trials. The laboratory diagnosis of copper deficiency is currently based on liver and either plasma or serum concentrations of copper. Ellison⁽²⁾ reviewed the copper reference range for cattle used by the animal health laboratories in New Zealand and concluded that there is strong agreement in the literature that serum copper concentrations greater than 7.9 𝛍mol/l and liver copper concentrations greater than 95 𝛍mol/kg are adequate for young cattle. Furthermore, it has been reported that if copper concentrations in the liver are greater than 150–200 𝛍mol/kg wet weight, there is a negligible increase in serum copper as liver concentrations increase further⁽²⁾, with individual animal variation accounting for the range of values in serum copper at this point (7.9–18 𝛍mol/l).     

Iatrogenic copper deficiency associated with long-term copper chelation for treatment of copper storage disease in a Bedlington Terrier

A 9-year-old Bedlington Terrier was evaluated because of weight loss, inappetence, and hematemesis. Copper storage disease had been diagnosed previously on the basis of high hepatic copper concentration. Treatment had included dietary copper restriction and administration of trientine for chelation of copper. A CBC revealed microcytic hypochromic anemia. High serum activities of liver enzymes, high bile acid concentrations, and low BUN and albumin concentrations were detected. Vomiting resolved temporarily with treatment, but the clinicopathologic abnormalities persisted. Results of transcolonic portal scintigraphy suggested an abnormal shunt fraction. Results of liver biopsy and copper quantification revealed glycogen accumulation and extremely low hepatic copper concentration. Serum and hair copper concentrations were also low. Chelation and dietary copper restriction were tapered and discontinued. Clinical signs and all clinicopathologic abnormalities improved during a period of several months.     

Effects of copper oxide bolus administration or high-level copper supplementation on forage utilization and copper status in beef cattle

Two experiments were conducted to study effects of high-level Cu supplementation on measures of Cu status and forage utilization in beef cattle. In Exp. 1, eight steers randomly received an intraruminal bolus containing 12.5 g of CuO needles (n = 4) or no bolus (n = 4). Steers were individually offered free-choice ground limpograss (Hemarthria altissima) hay. On d 12 (Period 1) and d 33 (Period 2) steers were placed in metabolism crates, and total forage refused and feces produced were collected for 7 d. Daily samples of forage offered and refused and of feces excreted for each steer within period were analyzed for DM, ash, NDF, ADF, and CP. Liver biopsies were collected on d 0, 12, and 33. Copper oxide bolus administration resulted in greater (P < 0.03) liver Cu (DM basis) accumulation in Period 1 (556 vs. 296 mg/kg) and Period 2 (640 vs. 327 ppm). Apparent digestibilities of NDF and CP were greater (P < 0.04) for steers receiving no bolus in Period 2 (62.2 vs. 57.1% and 50.2 vs. 43.4% for NDF and CP digestibility, respectively). In Exp. 2, 24 crossbred heifers were assigned to individual pens and received a molasses-cottonseed meal supplement fortified with 0, 15, 60, or 120 ppm of supplemental Cu (Cu sulfate; six pens per treatment). All heifers were offered free-choice access to ground stargrass (Cynodon spp.) hay. Heifer BW and liver biopsies were collected on d 0, 42, and 84. Forage refusal was determined daily, and diet DM digestibility was estimated over a 21-d period beginning on d 42. Heifers consuming 120 ppm of supplemental Cu gained less (P < 0.05; 0.04 kg/d) than heifers consuming 15 (0.19 kg/d) and 60 ppm of Cu (0.22 kg/d), but their ADG did not differ from that by heifers consuming no supplemental Cu (0.14 kg/d; pooled SEM = 0.07). Heifers supplemented with 15 ppm of Cu had greater (P < 0.05) liver Cu concentrations on d 84 than those on the 0-ppm treatment and the high-Cu treatments (60 and 120 ppm). Forage intake was less (P = 0.07) by heifers receiving no supplemental Cu than by heifers on all other treatments (6.6 vs. 5.8 +/- 0.37 kg/d). Apparent forage digestibility was not affected by Cu treatment. These data suggest that high rates of Cu supplementation (Cu sulfate; > 60 ppm of total Cu) resulted in less liver Cu accumulation by beef heifers compared with heifers consuming diets supplemented with moderate dietary Cu concentrations (i.e., 15 ppm). As well, the administration of CuO boluses might depress the digestibility of forage nutrient fractions in steers.     

Comparison of copper heptonate with copper oxide wire particles as copper supplements for sheep on pasture of high molybdenum content

OBJECTIVE: To assess the effectiveness of intramuscular injection of copper heptonate (CuHep) and an oral dose of copper oxide wire particles (COWP) in preventing Cu inadequacy in adult and young sheep on pasture of high Mo content. DESIGN: Field experiments with flocks of mature Merino wethers and crossbred weaners. PROCEDURE: Adult wethers were given 25 or 37.5 mg Cu as CuHep, 2.5 g COWP or no Cu treatment. The weaners were given 12.5 or 25 mg Cu as CuHep, 1.25 g COWP or no Cu treatment. At intervals over the next 12 (adults) or 8 (weaners) months the sheep were weighed and samples of blood and liver were collected for trace element assay. Wool samples collected from the adults at the end of the experiment were assessed for physical characteristics. RESULTS: The higher dosage of CuHep raised liver Cu above control group values for at least 9 months in adults and 3 months in weaners. The lower dosage of CuHep was similarly effective for 3 months in adults but was without effect in weaners. In adults the response to COWP matched that to the higher dosage of CuHep; in weaners it was greater, lasting at least 5 months. No changes indicative of Cu deficiency, apart from a depressed body weight in adults, were seen. CONCLUSIONS: In sheep on pasture of high Mo content a single intramuscular injection of CuHep providing 37.5 mg Cu to adults or 25 mg Cu to weaners will raise liver Cu reserves for at least 9 and 3 months respectively and may be an acceptable alternative to COWP for preventing seasonal Cu deficiency in sheep in southern Australia.     

Pathobiology of copper toxicity

A review is presented of various aspects of copper (Cu) metabolism. The Cu absorption from the gastrointestinal tract in monogastric animals differs from that in ruminants. This is influenced by Cu binding compounds, sulphide production in the rumen, and molybdenum and zinc concentrations of the diet. Moreover, the valence of the Cu ions may influence the availability of Cu in the intestine. Metallothionein and lysosomes are involved in the accumulation of copper in the liver. The different findings in various Cu storage diseases may reflect different mechanisms of disease. Cu-induced liver cell damage and haemolysis may be the result of lipid peroxidation.     

Comparative metabolism of copper

Copper is required in trace amounts for many body functions. The prominent effects of Cu deficiency or Cu toxicosis differs greatly between animal species. Along with iron, Cu is necessary for the transfer of O2 via a cascade of enzymes so that energy may be available for vital body functions without overheating of the tissues through rapid oxidation. As a part of lysyl oxidase, Cu has an obligate function in the maturation of all connective tissue (including elastic tissue and bone) maintaining the form and integrity of all body organs. As a constituent of tyrosinase, Cu is involved in the formation of melanin, thus preventing albinism. Copper also is involved in the myelination of nerve fibers and the production of neutrophils, enkephalins, lipoproteins, and cholesterol. Copper must be properly sequestered to prevent toxicosis. Copper is stored primarily as metallothioneins and as superoxide dismutase and is transported primarily as ceruloplasmin or as low molecular weight proteins, peptides, and amino acids.     

Effects of concurrent copper deficiency and gastro-intestinal nematodiasis on circulating copper and protein levels, liver copper and bodyweight in sheep

Sheep were rendered hypocupraemic using parenteral ammonium tetrathiomolybdate (ATM). Fifteen thousand third stage larvae of Trichostrongylus axei and T. colubriformis in the ratio 1:1 were administered three times per week for six weeks, starting four weeks after cessation of ATM treatment. The changes in liver and plasma copper (Cu), caeruloplasmin activity, serum proteins, faecal nematode egg counts and total nematode counts were measured in the sheep for 10 weeks after infection. Decreases in liver Cu, plasma Cu and caeruloplasmin activities were detected soon after infection. There was a significant (P less than 0.05) interaction of the effects of Cu deficiency and nematode infection on these changes. Hypoproteinaemia, attributed to serum albumin loss, was demonstrated seven weeks after infection, but this was not associated with the interaction of Cu deficiency and nematode infection. No changes in serum globulins were detected. Although the results support the contention that gastro-intestinal nematodiasis can significantly exacerbate an existing Cu deficiency in sheep, there was no evidence that hypocuprosis would predispose sheep to higher nematode burdens.     

Use of orally administered oxidised copper wire particles for copper therapy in cattle

Oxidised copper wire particles (OCWP) were given per os to cattle as an alternative to subcutaneous copper glycinate injections. OCWP were recovered from the stomachs of cattle slaughtered 3 months after treatment. OCWP (50g) treatment resulted in sustained higher plasma copper concentrations than subcutaneous injections of copper glycinate. OCWP given at high doses (300g) raised liver copper concentrations to 16 mmol/kg without clinical effects. It is concluded that OCWP could be a practical alternative to current injection methods of copper therapy.     

蛋氨酸铜对绵羊增重及体内代谢的影响

26只晋中绵羊随机分为试验组(添加蛋氨酸铜)和对照组(添加硫酸铜),供试日粮及营养水平完全相同,试验时间60d。结果表明,试验组比对照组绵羊平均日增重提高34.22%(P<0.05);平均日粮干物质采食量、肝脏铜和血浆铜含量明显提高(P<0.05)。