溶液型微量元素预混合饲料中钙、镁元素的测定探讨

本文就溶液型微量元素预混合饲料中钙、镁元素的测定作一探讨,利用EDTA-2Na与金属离子形成络合物的络合滴定法,在pH=10的条件下,用铬黑T为指示剂测出钙镁总量;在pH=12的条件下,用紫脲酸铵为指示剂测出钙含量;以总量减分量法计算出镁含量。     

羟基蛋氨酸钙含量测定方法比较研究

本文对测定饲料添加剂羟基蛋氨酸钙含量的3种方法:专属指示剂法、自身指示剂法和电位滴定法进行了比较研究。结果表明,专属指示剂法和电位滴定法重现性比较好,测定结果分别略高于标准值0.08%～0.27%和0.11%～0.30%,而自身指示剂法的重复测定间变异比较大,测定结果比标准值低0.25%～0.45%。     

羟基蛋氨酸钴螯合物稳定常数测定及其质量评价

羟基蛋氨酸微量元素螯合物的稳定常数是影响其生物学利用率的重要指标。羟基蛋氨酸微量元素螯合物中羟基蛋氨酸的含量及其纯度是评价产品质量的重要依据。本文采用分光光度法测定了实验室自制的羟基蛋氨酸钴螯合物样品的配位数和稳定常数,采用自动电位滴定法测定了样品中羟基蛋氨酸和羟基蛋氨酸钴的质量百分含量,对其质量进行了评价。研究结果证明,实验室前期自制的羟基蛋氨酸钴样品的表观稳定常数为4.71×105.46;样品中羟基蛋氨酸的含量为83.20%,羟基蛋氨酸钴的含量为98.97%。这不仅说明自制的羟基蛋氨酸钴样品纯度高,质量好;同时也说明结合分光光度法和自动电位滴定法对羟基蛋氨酸盐进行质量评价,方法简单、操作方便、数据可靠,能够满足同类产品生产企业日常质量检验需求。     

微波辅助消解-原子吸收光谱法测定猪饲料中铜、锌元素的含量

目的:测定猪饲料中铜、锌的含量。方法:采集猪饲料0.200 0 g,采用微波消解、火焰原子吸收法检测饲料中铜、锌的含量。结果:饲料中铜、锌含量分别为106.3、245.6μg/g,加样回收率分别为107.0%、95.2%,相对标准偏差(RSD)分别为2.937%、0.577%。结论:饲料中铜、锌的含量均符合国家标准;该法具有检出限低、灵敏度高、快速、准确的特点,用于实际样品测定的结果令人满意。     

羟基蛋氨酸螯合铜对断奶仔猪和育肥猪生长性能及组织铜含量的影响

文章旨在评估日粮添加有机铜(羟基蛋氨酸铜)及不同铜源和添加水平对仔猪和育肥猪生长性能及组织铜含量的影响。本研究共分为3个试验,试验1评估日粮添加6和170 mg/kg硫酸铜及170 mg/kg羟基蛋氨酸铜对1~42 d断奶仔猪生长性能和组织铜含量的影响。试验2评估日粮不同铜源对1~21 d仔猪生长性能和肝脏微量元素含量的影响。试验3评估日粮不同铜源对育肥猪屠宰性能的影响。与对照组和硫酸铜组相比,羟基蛋氨酸铜组仔猪末重均提高6%(P0.05)。与硫酸铜组相比,羟基蛋氨酸铜组1~14 d仔猪日增重和日采食量分别提高了22.9%和8.6%(P0.05),同时显著降低了料比(P0.05)。硫酸铜组肝脏铜含量较对照组提高了2.7倍(P0.05),较羟基蛋氨酸铜组提高了4.5倍(P0.05)。羟基蛋氨酸铜组较对照组和碱铜组显著提高了肝脏铜含量(P0.05)。80 mg/kg羟基蛋氨酸铜组较对照组和160 mg/kg硫酸铜组显著提高了育肥猪屠体重(P0.05)。80和160 mg/kg羟基蛋氨酸铜较160 mg/kg硫酸铜和对照组显著提高了眼肌深度(P0.05)。综上所述,羟基蛋氨酸铜可以提高仔猪的生长性能和肝脏铜含量,但对仔猪促生长作用所需的添加量较硫酸铜小。80 mg/kg羟基蛋氨酸铜可以提高育肥猪生长性能和眼肌深度。     

不同饲料铜源体外溶解度的研究

选取硫酸铜、富铜酵母、赖氨酸铜、蛋氨酸铜和包被铜作为牛的饲料铜源,选用去离子水、稀酸溶液和缓冲液分别模拟牛消化道内的不同环境,进行体外溶解性试验,试验结果表明,硫酸铜、赖氨酸铜和蛋氨酸铜在各种溶剂中均有较高的溶解度,富铜酵母在缓冲液中的溶解度低,但在稀酸中的溶解度较高。包被铜在去离子水和缓冲液中的溶解度低,但在稀酸中的溶解度高。因此,包被铜是饲料无机铜源,蛋氨酸铜、赖氨酸铜是适宜有机铜源。     

蛋氨酸铜对猪血清铜锌含量及粪铜锌排泄量的影响

为了研究饲粮中添加蛋氨酸铜与硫酸铜对生长猪生长性能、养分消化率、血清铜锌含量及粪铜辞排泄量的影响.选择体重为17.17±2.34kg(P＞0.05)的二元杂交(长×大)生长阉公猪30头进行试验,试猪按完全随机区组设计,依体重和窝别随机分为5个处理,每个处理3个重复,每个重复2头猪,分别饲喂10、150、250mg/kg蛋氨酸铜和150、250mg/kg硫酸铜,试验期30 d.结果表明:饲喂蛋氨酸铜组ADG、F/G及表观养分消化率具有明显的优势;血清铜含量随饲粮铜水平的提高而发生显著变化,而高铜组组问血清锌差异不显著;蛋氨酸组粪铜排泄量比硫酸铜组粪铜排泄量显著降低.说明:添加中等水平的有机蛋氨酸铜吸收利用率比高剂量硫酸铜高,且可减少粪铜、锌的排泄.     

羟基蛋氨酸螯合物在动物生产中的应用

羟基蛋氨酸螯合物是由蛋氨酸羟基类似物(2—羟基4—甲琉基丁酸)与微量元素金属离子在一定的pH值、压力和反应温度等外界条件作用下,按1:1摩尔比螯合而成的呈五元环状结构的产品,羟基蛋氨酸螯合铁、铜、锌、锰,产品中金属元素含量12%,含羟基蛋氨酸30%～35%。     

蛋氨酸铜对猪血清铜锌含量及粪铜锌排泄量的影响

为了研究饲粮中添加蛋氨酸铜与硫酸铜对生长猪生长性能、养分消化率、血清铜锌含量及粪铜锌排泄量的影响。选择体重为17．17±2．34kg（P〉0．05）的二元杂交（长×大）生长阉公猪30头进行试验,试猪按完全随机区组设计,依体重和窝别随机分为5个处理,每个处理3个重复,每个重复2头猪,分别饲喂10、150、250mg／kg蛋氨酸铜和150、250mg／kg硫酸铜,试验期30d。结果表明：饲喂蛋氨酸铜组ADG、F／G及表观养分消化率具有明显的优势;血清铜含量随饲粮铜水平的提高而发生显著变化,而高铜组组间血清锌差异不显著;蛋氨酸组粪铜排泄量比硫酸铜组粪铜排泄量显著降低。说明：添加中等水平的有机蛋氨酸铜吸收利用率比高剂量硫酸铜高,且可减少粪铜、锌的排泄。     

铜对仔猪血清微量元素水平的影响

为了探讨不同铜源对仔猪生长性能和血清微量元素含量的影响,试验选用体重20 kg左右的军牧1号断奶仔猪75头,随机分成A、B、C、D、E 5组,分别为基础日粮对照组（A组）、基础日粮＋125 mg/kg硫酸铜组（B组）、基础日粮＋250 mg/kg的硫酸铜组（C组）、基础日粮＋125 mg/kg蛋氨酸铜组（D组）、基础日粮＋250 mg/kg蛋氨酸铜组（E组）,试验期为45 d。在试验第15,30,45天晨饲前空腹采血,分离血清用于测定有关微量元素含量;测定各组猪生长性能。结果表明：日粮添加铜可显著提高血清铜、锌含量（P〈0.05）,对血清铁含量无显著影响（P〉0.05）;125 mg/kg蛋氨酸铜和125 mg/kg硫酸铜的促生长效应较显著（P〈0.05）,且有机铜优于无机铜。说明添加铜对仔猪生长有一定的意义,建议在基础日粮中添加铜125 mg/kg。     

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.