Biochemical and pathological changes in tissues of Friesian cattle during the experimental induction of copper deficiency

UK ruminant farmer understanding of copper-related terminology

Copper provision is not straightforward in ruminants. Other dietary elements such as iron and molybdenum in combination with sulphur are able to interfere with copper availability, absorption and function. These complexities surrounding copper availability in cattle and sheep prevent the simple calculation of copper requirements. Previous research has established that UK farms are failing to provide copper in an effective manner, with some over-supplying and others under-supplying. Copper terminology is not consistently understood by professionals in the agricultural industry; potentially resulting in confusing or misinformation being passed on to farmers. The present work found that most (84 %) farmers felt they lacked understanding of copper related problems and their associated terminology. However, farmers who felt they had the least knowledge appeared more likely to underestimate their knowledge, and those who felt more confident in their knowledge were more likely to be overestimating it. Simple over- and under-supply of copper were only recognised by a small proportion (17 %) as causes of copper related problems while more complex issues were better recognised (27 %) as potential causal factors. However, the more specific terminology relating to the molybdenum-sulphur antagonism was poorly understood by most respondents (96 %).

Determination of dietary copper requirement by the monoamine oxidase activity in kidney of broilers from 1 to 21 d of age

The current dietary copper (Cu) requirement (8 mg/kg) of broilers is mainly based on growth, hemoglobin concentration, or hematocrit, which might not be the most sensitive indices to evaluate dietary Cu requirements of broilers. The present study was carried out to estimate dietary Cu requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 d of age using biochemical or molecular biomarkers. A total of 384 1-d-old Arbor Acres male broilers were randomly allocated to 1 of 6 treatments with 8 replicates and fed a Cu-unsupplemented corn-soybean meal basal diet containing 5.17 mg Cu/kg by analysis and the basal diet supplemented with 3, 6, 9, 12 or 15 mg Cu/kg as CuSO₄⋅5H₂O for 21 d. Regression analysis was performed to estimate the optimal dietary Cu level using the broken-line model. Dietary supplemental Cu level affected (P < 0.05) Cu contents in serum and liver and kidney monoamine oxidase (MAO) activity, but had no effects (P > 0.05) on the growth performance, Cu contents in heart, kidney, pancreas and spleen, Cu- and zinc-containing superoxide dismutase (CuZnSOD) activity and ceruloplasmin content in serum, CuZnSOD and cytochrome c oxidase (COX) activities and ceruloplasmin, CuZnSOD, MAO A, MAO B, COX4I1 and COX1 mRNA and protein expressions in the above tissues of broilers. As dietary supplemental Cu levels increased, Cu contents in serum and liver increased linearly (P < 0.05), but kidney MAO activity decreased linearly and quadratically (P < 0.05). The estimated dietary Cu requirement based on the fitted broken-line model (P = 0.035) of kidney MAO activity was 11.30 mg/kg. In conclusion, kidney MAO activity is a new and sensitive criterion to evaluate the dietary Cu requirement of broilers, and the dietary Cu requirement was 11.30 mg/kg for broilers fed the conventional corn-soybean meal diet from 1 to 21 d of age, which is higher than the current National Research Council (NRC) Cu requirement (8 mg/kg) of broilers.

Decrease lysyl oxidase activity in hearts of copper-deficient bovines

BACKGROUND

Lysyl oxidase (LOX) is a metalloenzyme that requires Cu as a cofactor and it is responsible for the formation of collagen and elastin cross-linking. The objective of this work was to measure the LOX enzyme activity in the heart of bovines with Cu deficiency induced by high molybdenum and sulfur levels in the diet.

METHODS

Eighteen myocardial samples were obtained from Cu-deficient (n = 9) and control (n = 9) Holstein bovines during two similar assays. The samples were frozen in liquid nitrogen and stored at -70 °C to measure enzymatic activity. A commercial kit was used, following producer instructions.

RESULTS

The results showed that LOX activity from the hearts of Cu-deficient bovines is 29 % lower than the ones of control bovines, being this difference statistically significant (p = 0.03).

CONCLUSION

To our knowledge, this is the first report that determined LOX enzymatic activity in bovine heart of Cu-deficient animals. The microscopic alterations found in these animals in our previous work, could be explained by a diminished LOX activity. The results are in agreement with other authors, who found a relationship between LOX activity and dietary Cu intake. The information provided by this work could help to clarify the pathogenesis of cardiac lesions in cattle with dietary Cu deficiency.

Effects of bismuth subsalicylate and encapsulated calcium-ammonium nitrate on enteric methane production, nutrient digestibility, and liver mineral concentration of beef cattle

Two randomized block designs were performed to evaluate the effects of bismuth subsalicylate (BSS) and encapsulated calcium-ammonium nitrate (eCAN) on enteric methane production, nutrient digestibility, liver mineral concentration, and performance of beef cattle consuming bahiagrass hay (Paspalum notatum; ad libitum) and sugar cane molasses [1.07 kg/d; dry matter basis]. Experiment 1, used 25 crossbred steers [335 ± 46 kg of initial body weight (BW)] with a 2 × 2 + 1 factorial arrangement of treatments for two 20 d periods. Factors were nonprotein nitrogen (NPN) source (350 mg/kg BW of nitrate or 182 mg/kg BW of urea), BSS (0 or 58.4 mg/kg BW), and a negative control (NCTRL; bahiagrass hay and molasses only). Steers were re-randomized for a second period (n = 10/treatment total). Intake, apparent total tract digestibility and enteric methane were evaluated. Experiment 2 used 75 crossbred heifers in 25 pens (3 heifers/pen; 279 ± 57 kg of initial BW), consuming the same diet and treatments as experiment 1, to determine liver mineral concentration and growth performance over 56 d. Orthogonal contrasts were used to evaluate the effects of NPN (NCTRL vs. others), source of NPN (NS; urea vs. eCAN), BSS, and NS × BSS. For experiment 1, no interactions were observed for any variables, nor were there any effects of NPN on total tract digestibility of nutrients, except for crude protein. Digestibility of all nutrients was reduced (P ≤ 0.021) for steers consuming eCAN compared with urea. There was no effect (P > 0.155) of BSS on digestibility of nutrients; however, BSS reduced (P = 0.003) apparent S retention. Enteric CH4 emission (g/kg BW0.75) was decreased (P = 0.051) by 11% with the addition of eCAN compared with urea. For experiment 2, no NS × BSS interactions (P ≥ 0.251) were observed to affect liver mineral concentration; however, the addition of BSS decreased liver concentration of Cu (P = 0.002) while increasing Fe concentration (P = 0.016). There was an NS × BSS interaction (P = 0.048) where heifers consuming eCAN and BSS had lesser final BW compared with heifers consuming urea and BSS. While eCAN may be a viable resource for mitigating enteric CH4 production of forage-fed cattle, the negative effects on digestibility should be considered. Furthermore, BSS, at the amount provided, appears to have no negative effects on digestibility of nutrients in forage-fed cattle; however, there may be deleterious impacts on performance depending upon what nitrogen source is supplied.

Biochemical and Morphological Alterations in Hearts of Copper-Deficient Bovines

Copper deficiency is an important disease of cattle that produces several clinical signs and lesions, due to alterations in copper-dependent enzymes. One of the organs affected by this deficiency is the heart (falling disease), but nevertheless, these cardiac lesions have not been extensively studied in bovines. The aim of this work was to propose a possible pathogenic mechanism for cardiac lesions in cattle affected by copper deficiency. Because of the possible existence of oxidative distress caused by low levels of copper-zinc-superoxide dismutase and cytochrome oxidase, ultrastructural and histological lesions have been evaluated in the heart of bovines in which a Cu deficiency had been induced using high molybdenum and sulfur levels in the diet. Our results indicated that copper deficiency produces significant damage in myocardium with high levels of lipid oxidation and a significant reduction in copper-zinc-superoxide dismutase activity leading to an oxidative distress situation. However, cytochrome oxidase activity was not significantly reduced. Histological observation revealed a significant increase in the amount of connective tissue, enlarged basement membranes of myocytes, and numerous Anichkov cells, in the hearts of deficient animals. Ultrastructural observation showed a significant enhancement in the mitochondrial volume density, with presence of lesions such as swelling and cristae disruption. We conclude that copper deficiency in bovines causes morphological lesions in the heart due to an oxidative damage produced by copper-dependent enzyme alterations.

Effect of Injectable Copper and Zinc Supplementation on Weight, Hematological Parameters, and Immune Response in Pre-weaning Beef Calves

Copper (Cu) and zinc (Zn) deficiency may cause poor weight gain, hematological changes, and immune failure in extensive beef cattle breeding systems. Diagnosis of the deficiency is based on plasma Cu and Zn concentrations; however, there are discrepancies regarding data interpretation. Here, plasma Cu and Zn concentrations are discussed as risk markers. We evaluated the effect of parenteral Cu and Zn supplementation on their plasma concentrations, weight gain, hematological parameters, and antibody titers to bovine herpes virus 1 (BoHV-1). Pre-weaning calves (n = 40; 99 ± 8 kg bw) from a typical breeding area of Argentina with background Cu and Zn deficiency were used. They were assigned to two homogeneous groups in a completely randomized design. Calves were subcutaneously injected with 0.3 mg/kg Cu and 1 mg/kg Zn (supplemented group), or saline solution (control), every 40 days during 120 days. Plasma Cu and Zn concentrations, hematological parameters, and weight were recorded. On days 40 and 80 of the trial, calves were vaccinated with inactivated BoHV-1. Antibody immune response was measured on days 80 and 120. Data were analyzed with a mixed model for repeated measures over time. Before treatment, plasma Cu was low and Zn was adequate in both groups. After treatment, plasma Cu increased and remained within a normal range, whereas plasma Zn remained constant. Supplemented animals had higher weight gain (p < 0.01); higher hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin levels (p < 0.05); and higher immune response to BoHV-1 (p < 0.05). Our results suggest that Cu and Zn supplementation improved daily weight gain and the immune response of pre-weaning calves.

Relative bioavailability of organic and hydroxy copper sources in growing steers fed a high antagonist diet1

To assess relative bioavailability (RBV) of hydroxy and organic Cu sources compared with CuSO4 in steers fed a high Cu antagonist diet, 84 steers were stratified by BW to pens randomly assigned to dietary treatments for 90 d. Steers received a common corn silage-based diet supplemented with Cu antagonists (diet analyzed 0.25% S; 6.8 mg Mo/kg DM). Supplemental (SUPP) Cu treatments included: control (CON; no SUPP Cu), low or high inorganic (ING5 or ING10; 5 or 10 mg Cu/kg DM from CuSO4; Old Bridge Chemical Inc., Old Bridge, NJ, USA), low or high organic (ORG5 or ORG10; 5 or 10 mg Cu/kg DM from Cu lysine; CuPlex 100, ZinPro Corp., Eden Prairie, MN), and low or high hydroxy (HYD5 or HYD10; 5 or 10 mg Cu/kg DM; IntelliBond CII, Micronutrients USA LLC, Indianapolis, IN). Body weights were recorded on days -7, -6, 28, 56, 84, and 85, and plasma samples collected on days -7, 28, 56, and 85. Liver samples were collected to start and end the trial. Data were analyzed using the mixed procedure of SAS and the model included treatment with initial liver Cu values used as a covariate in analysis of final liver Cu. Contrast statements were used to separate treatment means: 0 vs. 5 mg SUPP Cu/kg DM, 0 vs. 10 mg SUPP Cu/kg DM, 5 vs. 10 mg SUPP Cu/kg DM, HYD vs. ORG, HYD vs. ING, and ORG vs. ING. Initial liver Cu concentrations were similar across all treatment comparisons (P ≥ 0.22). Final liver Cu concentrations were lesser in CON compared with either 5 or 10 mg Cu/kg DM (P ≤ 0.001). Final liver concentrations were lesser in ORG compared with HYD and ING (P ≤ 0.009), but HYD was similar to ING (P = 0.14). There was a treatment × time interaction (P ≤ 0.001) for plasma Cu concentrations where CON exhibited a rapid decline in plasma Cu, steers receiving 5 mg SUPP Cu/kg DM were decreased to a greater extent in ORG, and steers supplemented with 10 mg Cu/kg DM did not differ at the end of the trial. Assessment of RBV was conducted for liver and plasma Cu concentrations using a slope-ratio assay in the GLM procedure. The RBV of Cu tended (P = 0.07) to be increased in HYD (112%) compared with ING (100%) for liver Cu values, but RBV was similar for all other source comparisons based on liver and plasma Cu values (P ≥ 0.22). These data suggest in steers fed high antagonist diets hydroxy Cu may be more available. Based on plasma and liver Cu concentrations, supplementation of 10 mg Cu/kg DM is needed to maintain Cu status in cattle fed diets high in S and Mo.

Copper and Zinc Nutritional Issues for Agricultural Animal Production

Livestock have presented unique requirements and toxicity issues depending on the species for the various concentrations of Cu and Zn and their interactions with other nutrients especially Fe, Se, Mo, and S. Soil concentrations of these elements and their availability to crops influence the health of the crop and the amount found in vegetative tissues and seeds. Hence, many livestock issues are a result of the soils in the area where production is occurring (Loneragan et al. 1981). While water can provide minerals to animals, the amount consumed and availability are highly variable. Many discoveries about Cu were a result of low Cu concentrations and its availability due to interactions with other nutrients in the soils. Anemia, bone disorders, cardiovascular abnormalities, defective wool and hair, and infertility are signs/symptoms of Cu deficiency. Toxicity due to excess Cu is more likely to occur in sheep than other farm species. Swine are tolerant of high concentrations of dietary Cu, and it is often used as a growth stimulant in production. There are many species and physiological stages where the animal's Cu requirement is not known. Grazing animals can exhibit Zn deficiency when soils and forages contain limited concentrations of Zn. Pastures have been observed to be Zn-deficient in many parts of the world. However, non-ruminant animals usually receive adequate Zn when fed corn and soybean meal diets if there is not excessive Ca and Fe in their diets, but this is not true for rapidly growing young animals. Characteristics of a Zn deficiency include loss of appetite, reduced growth and reproduction, and impaired health of bone and skin tissues.

Effect of trace mineral source on mineral status and performance of beef steers fed low- or high-sulfur diets

A 2 × 2 factorial assessed the effect of trace mineral (TM) sources fed within low- or high-S diets on the mineral status and performance of cattle. Angus crossbred steers ( = 48; 6/pen) were blocked by BW (316 ± 16.6 kg), assigned to low-S (0.27%; LS) or high-S (0.54%; HS; added as CaSO) diets, and supplemented TM at 10 mg Cu, 30 mg Zn, and 20 mg Mn/kg DM from hydroxy (HYD; IntelliBond; Micronutrients USA LLC, Indianapolis, IN) or inorganic (sulfates; ING) sources ( = 12 steers/treatment). Steers were fed corn silage and corn-based diets via GrowSafe bunks in the growing period (GP; 84 d) and finishing period (FP; 77 d), respectively. Plasma and liver were collected at trial initiation and end of GP and FP for mineral concentrations. End of GP and FP red blood cell lysate superoxide dismutase (SOD) and Mn-SOD activity and liver glutathione concentrations were measured. Data were used as a 2 × 2 factorial using Proc Mixed of SAS (SAS Inst. Inc., Cary, NC) with initial plasma and liver status analyzed as covariates. High S decreased ( < 0.01) liver Cu and tended ( ≤ 0.10) to decrease plasma Cu concentrations. Liver Cu concentrations were lower in HYD than ING in the FP ( < 0.01). High S decreased ( = 0.04) GP plasma Zn concentrations and tended to decrease ( = 0.10) GP liver Zn. There were GP ( = 0.05) and FP ( = 0.02) S × TM effects for liver Mn concentrations where GP LS-HYD was greater than all other treatments, whereas FP LS-HYD was lower than HS-HYD and LS-ING and FP HS-ING was less than LS-ING. Glutathione, SOD, and Mn-SOD were not different ( ≥ 0.13) in the GP, but S × TM tended to affect FP Mn-SOD ( = 0.10), where LS-HYD tended to be lower than LS-ING. Oxidized glutathione in FP tended to be lower ( = 0.06) for HYD than ING. In the GP, there were S × TM effects on performance where LS-HYD had greater ADG and G:F ( ≤ 0.05) than HS-HYD, whereas LS and HS-ING were intermediate. For FP performance S × TM effects were noted where LS-HYD and HS-ING tended ( = 0.10) to gain more than HS-HYD and HS-HYD had lower G:F ( = 0.04) than HS-ING. There were no effects of S × TM on final BW, DMI, or ADG ( ≥ 0.11); however, HS-HYD had lower G:F than other treatments overall ( = 0.05). High S decreased back fat and yield grade ( = 0.03), and rib eye area was smaller for HYD than ING ( = 0.02). In this study HS decreased markers of Cu and Zn status, and differential effects of HYD vs. ING minerals were noted across dietary phases, although all steers maintained adequate TM status.

1.1 The Physiological and Pathological Basis of Trace Element Deficiency Disease

No reliable statistics are available from which to assess the economic losses caused annually in the UK or elsewhere by trace element deficiency diseases in farm livestock. However, data such as those provided by the Veterinary Investigation Diagnosis Analysis Service or by annual FAO/WHO Reports on Animal Health clearly indicate that, in many instances, the circumstances leading to the development of trace element deficiency diseases are neither effectively recognized nor anticipated.

3.2 The Role of Dose-Response Trials in Predicting Trace Element Deficiency Disorders

The symptoms of trace element deficiency arise from the combined effects of the different lesions provoked within the animal body. Since a variety of different lesions have been described, many of which affect inter-related systems, it is not surprising that diverse symptoms may arise even from the one trace element deficiency; nor that similar symptoms may be caused by deficiencies of different trace elements. The major effects of trace element deficiencies on body functions have been outlined in Table 3.2.1 (from Underwood, 1980).

Intestinal Alterations, Basal Hematology, and Biochemical Parameters in Adolescent Rats Fed Different Sources of Dietary Copper

Copper (Cu) is required for basically all biochemical and physiological processes in the body. The aim was to evaluate the effects of different sources of dietary copper on jejunal epithelium histomorphometry in adolescent rats. Male rats at the age of 5 weeks were used in the 12-week experiment. The control group was fed with standard diet providing the required Cu level (5 mg/kg body weight (bw) per day) in an inorganic form (sulfate) covered 100 % of daily demand, and the other three groups were supplemented with Cu-glycine complex covered 50, 75, and 100 % daily demand. Basal hematological and plasma biochemical analyses as well as histomorphometric examinations of the jejunal epithelium and liver were performed. Cu given in the organic form in 100 % of daily demand depressed the muscular and submucosa layer and the crypt depth (P < 0.05) without an influence of the innervation of the jejunum. In turn, organic Cu given in 75 % of daily demand did not influence the intestinal morphology in adult rats. Dietary organic Cu given to rats covering the daily demand in 50 or 75 % appears to be less harmful with regard to the intestinal epithelium than when administered in 100 % of daily demand.

Macrominerals and Trace Element Requirements for Beef Cattle

Eighty-seven Nellore animals were utilized in this study to estimate net requirements for the maintenance and growth of beef cattle as well as the retention coefficients of 13 minerals: macrominerals (Ca, P, Mg, K, Na, and S) and trace elements (Cu, Fe, Mn, Se, Zn, Co, and Cr). The net requirements for maintenance and the true retention coefficient were estimated by using the regression between apparent retention and intake for each mineral. The net requirement for maintenance (μg/kg BW) and retention coefficients (%) were 163 and 85 for Cu, 2,097 and 53 for Fe, 32.3 and 24 for Mn, 3.72 and 48 for Se, 669 and 0.80 for Zn, 18.4 and 86 for Co, and 22.9 and 78 for Cr. The dietary requirements of macrominerals (g/kg DMI) were 5.12 for Ca, 2.38 for P, 0.96 for Mg, 2.40 for K, 0.79 for Na, and 1.47 for S. This is the first study using Nellore cattle to estimate mineral requirements; considering that Nellore cattle are the most common breed in Brazil and that Brazil is a major beef producer globally, this knowledge can help producers to improve animal performance by supplying the correct amount of minerals.

Serum copper and haematological values of sheep of different physiological stages in the dry and wet seasons of central trinidad

A study was conducted to determine serum copper (Cu) concentrations and hematological values of 174 sheep from four medium sized farms, pertaining to physiological stage, in the late dry and late wet seasons of Central Trinidad. Serum Cu was significantly lower in the dry than in the wet season (P < 0.001) with a corresponding high percentage of samples with low Cu levels in the former. 31% of dry nonpregnant sheep exhibited a nonregenerative anaemia. Also, hemoglobin and packed cell volume values varied (P < 0.001) including lymphocyte (P < 0.01) counts, among growing animals compared with other physiological stages. Significant variations also occurred among neutrophil (P < 0.05) and eosinophil (P < 0.05) values in sheep. Highest haemoglobin and packed cell volume, white blood cell counts, and lymphocyte values in growing sheep compared with other stages were probably age related.

Using sodium molybdate to treat chronic copper toxicity in dairy cows: A practical approach

Abstract

CASE HISTORY

A Jersey herd of 350 cows and 70 heifers located in the Taranaki region of New Zealand ceased milking in June 2011. Ten cows died during the subsequent 14 days. For at least 9 months, the cows had received palm kernel expeller (PKE) and molasses supplements. Additional Cu supplementation was provided through the water system. Total Cu intake was calculated to be 400 mg/day/cow.

CLINICAL AND PATHOLOGICAL FINDINGS

Half of the cows died suddenly while others presented with anorexia, depression and ataxia, which progressed to recumbency and death after 1 to 3 days. Clinical signs were mild dehydration, cyanosis and firm faeces which were covered in dark blood. Mean concentrations of Cu in liver and kidney in three of the dead cows were 3,900 and 440 µmol/kg fresh weight (FW), respectively. Haemorrhages were observed throughout the alimentary tracts and in muscles, and there were ecchymotic haemorrhages on the epi- and endocardia. The livers were swollen and the gall bladder walls were inflamed.

DIAGNOSIS

High concentrations of Cu in the liver and kidney are characteristic findings of chronic Cu toxicity.

TREATMENT

The remaining herd was fed 200 mg Mo, as sodium molybdate, per cow per day and all Cu supplements were removed including those provided by the water supply. This reduced mean concentrations of Cu in liver from 3,100 to 1,320 µmol/kg FW within 26 days in the five live animals that were biopsied. There were no further deaths.

CLINICAL RELEVANCE

In dairy herds where excessive Cu intakes have resulted in high liver Cu concentrations and caused chronic Cu toxicity, the removal of all Cu supplements and provision of high intakes of Mo (200 mg/cow/day) can markedly reduce liver Cu stores within 4 weeks.

Effect of dietary copper and breed on gene products involved in copper acquisition, distribution, and use in Angus and Simmental cows and fetuses

Copper (Cu) deficiency is a widespread problem in cattle across the United States and breed differences in Cu metabolism may contribute to this issue. Intracellular Cu is tightly regulated by transport and chaperone proteins, and to date, these mechanisms have not been elucidated to address breed differences in Cu metabolism, nor have these proteins been characterized in bovine fetal liver. Mature, pregnant Angus (n = 8) and Simmental (n = 8) cows (∼4 mo into gestation) were used in a 2 × 2 factorial arrangement of treatments. All cows were bred to Angus sires resulting in an Angus vs. Simmental × Angus comparison for fetuses. Cows were randomly assigned to corn silage-based diets that were either adequate (+Cu) or deficient (-Cu; 6.6 mg Cu/kg DM) in Cu. Diets were individually fed for 112 d. At the end of the study, cows were harvested to collect duodenal mucosa scrapes, liver samples, and fetal liver samples for mineral analysis and also for mRNA and protein analysis of Cu transport and chaperone proteins. Placentomes were also obtained for mineral analysis. Plasma Cu and liver Cu were affected by Cu, breed, and Cu × breed. Both of these Cu indices were less (P ≤ 0.05) in-Cu Simmentals (-CuS) than in-Cu Angus (- uA), but were similar among +Cu Simmental (+CuS) and +Cu Angus cows (+CuA). Duodenal Cu was less (P = 0.01) in-Cu vs. +Cu cows. Placentome Cu was less (P = 0.003) in-Cu vs. +Cu cows, and was also less (P = 0.03) in Simmentals vs. Angus. Fetal liver Cu was less (P = 0.002) in-Cu vs. +Cu fetuses, and was also less (P = 0.05) in Simmental × Angus vs. Angus. Abundance of Cu transporter1 (CTR1) protein and transcripts for Cu transporters and chaperones were not affected by Cu or breed in liver and were not affected by Cu in the intestine. Duodenal Ctr1 was less (P = 0.04) and CTR1 tended (P = 0.10) to be less in Simmentals vs. Angus. Expression of Atp7a tended (P = 0.08) to be less in Simmentals than in Angus. In fetal liver, expression of antioxidant 1 (Atox1), cytochrome c oxidase assembly protein 17 (Cox17), and Cu metabolism MURR1 domain 1 (Commd1) were up-regulated (P ≤ 0.05) in-Cu vs. +Cu fetuses. In conclusion, less expression of duodenal Ctr1 and a tendency for less CTR1 (P = 0.10) and Atp7a (P = 0.08) suggest that Simmentals have a lesser ability to absorb and utilize dietary Cu, and may explain why Simmentals are more prone to Cu deficiency than Angus. Up-regulation of fetal liver Atox1, Cox17, and Commd1 in-Cu fetuses may reflect the great Cu demand by the fetus.

Diagnostic value of copper parameters to predict growth of suckling calves grazing native range in Argentina

A study was conducted to evaluate the predictive diagnostic value of different copper (Cu) parameters as indicators of average daily gain (ADG) in growing calves. The effects in calves of cow Cu supplementation in the last one-third gestation period were also evaluated. Five supplementation trials, with a total of 300 calves, were carried out. Two groups of 30 calves were randomly assigned to each trial, one group was parenterally supplemented (SG) and the other was not supplemented (NSG). Trials began when calves were three-month-old and ended at weaning time. At each sampling calves were weighed and blood was taken to determine Cu concentrations in plasma, Whole Blood (WB), Red Cells (RC) and Packed Cell Volume (PCV). Liver samples from six animals of each group were taken both at the beginning and at the end of the trial. In two trials the mothers of the SG received Cu supplementation at the last one- third gestation period. Four of the five trials exhibited low ADG in the NSGs. In these groups, plasma Cu concentration decreased rapidly before low ADG was detected, which occurred with values remaining below 25µg/dl. The decrease of RC Cu concentration was considerably slow. WB showed an intermediate position. PCV in the SGs was higher than in the NSGs in all trials. Cow supplementation was insufficient to generate a liver storage able to last after calves reached the 3 months of age. These data could be useful to predict the risk of low ADG in grazing calves.

Studies on lambs from lines genetically selected for low and high copper status 2. Incidence of hypocuprosis on improved hill pasture

Growth rate and the concentrations of various biochemical constituents were measured in 2 years in lambs from two lines, selected on low (L) and high (H) copper (Cu) concentrations in plasma, and from two unselected pure breeds, Scottish Blackface (B) and Welsh Mountain (W). The lambs grazed improved hill pastures and half were given Cu supplements.

H lambs were always heavier and were fattened for slaughter earlier than were L lambs, differences that were not completely eliminated when supplementary Cu was given. In both years, the improvements in growth rate due to supplementary Cu varied with genetic type (average L 20·5 (s.e. 2·5); H 5·7 (s.e. 2·6); B 25·1 (s.e. 3·7); W 8·1 (s.e. 3·3) g/day). Growth rates of supplemented lambs were L 100 (s.e. 2), H 104 (s.e. 2), B 134 (s.e. 5), W 103 (s.e. 3) g/day.

At 6 weeks of age, unsupplemented lambs trom all genetic types were hypocupraemic and, at all ages, unsupplemented L and B lambs had lower concentrations of Cu in plasma and superoxide dismutase (SOD) activity than had unsupplemented H and W lambs. Supplemented lambs always had greater concentrations of Cu in plasma and SOD activities than had their unsupplemented counterparts. Supplementation increased the haemoglobin concentration for B (in year 2) and L lambs but not for H and W lambs. Cholesterol concentrations in plasma were unaffected by selection but were slightly higher in unsupplemented lambs. The concentration of total protein and the activity of aspartate transaminase were unaffected by genotype or Cu supplementation. In the liver of lambs at slaughter, the concentration of Cu was lower for unsupplemented lambs and inversely related to the concentration of iron.

It was concluded that (i) genotype was an important determinant of hypocuprosis; (ii) the degree of hypocuprosis could not be predicted from herbage analyses alone, but instead may be predicted from biochemical assessment of the lamb; and (iii) the dose of Cu supplement used was inadequate for L and B lambs and recommended levels could be increased, within limits, without risk of toxicity.

The effect of copper treatment on the performance of hypocupraemic calves

1. Seven experiments involving 191 calves and 40 cows were under- taken over a 2-year period into the effect of copper treatment of hypocupraemic calves on their subsequent performance.

2. Significant increases in mean live-weight gain of copper-treated calves ranging from 19·9 to 34·3 kg/head relative to untreated control groups were obtained in three cases.

3. The frequency of copper injection required to maintain plasma copper levels above 0·60 mg/1 varied from 6 to 12 weeks.

4. The live-weight gain and plasma copper concentration responses are discussed in relation to the pasture herbage concentrations of copper, molybdenum and sulphate.

Iron-induced copper deficiency in calves: dose-response relationships and interactions with molybdenum and sulphur

The effects of dietary supplements of iron, molybdenum and sulphur on copper metabolism in calves were examined. In one experiment, 27 castrated male pre-ruminant Friesian calves were given a milk-substitute ration containing 0·9, 4·5 or 9 mmol iron per kg dry matter for 8 weeks. The iron supplements had no effect on liver copper retention. When 24 of these calves were then given a diet based on barley grains and barley straw containing 0, 4·5, 9 or 13·5 mmols iron per kg for up to 24 weeks, liver and plasma copper concentrations were greatly reduced in all iron-supplemented animals but no clinical signs of copper deficiency developed. Reduction in the dietary sulphur concentration from 88 o t 47 mmol/kg after 12 weeks did not prevent the iron-induced reduction in liver copper concentrations n i animals given 9 or 13·5 mmol iron per kg. Plasma copper concentrations increased in all iron-treated calves given the low-sulphur diets, except in animals given 13·5 mmol iron per kg. The results indicate that iron is a potent antagonist of copper metabolism in weaned calves and that its effects are probably independent of dietary sulphur supply.

In a second experiment 20 Hereford × Friesian female calves were given diets with supplements of 2·7 mmol iron and 20 μmol molybdenum per kg, separately and together, for 41 weeks. Both supplements reduced liver and plasma copper concentrations but only in the molybdenum-treated animals were live-weight gains reduced. The rate of decline in liver and plasma copper concentrations tended to be greatest in animals given both supplements, indicating that additive action of these antagonists is possible.

High and variable copper status identified among dairy herds in the Waikato region by concentrations of Cu in liver sourced from biopsies and cull cows

AIMS

To document the Cu supplementation practices on dairy farms in the Waikato region, determine the Cu status of those herds, and compare the suitability of liver samples sourced from biopsies and cull cows for assessing Cu status.

METHODS

During spring 2008, concentrations of Cu, Mo and S were determined from pasture samples from 24 dairy farms. Feeding regimens, herd size, milksolids production, soil type, fertiliser policy and Cu supplementation practices were recorded for each property. Based on these data, 10 monitor farms were selected to represent a range of Cu intakes for herds, from 5 to 12 mg Cu/kg dry matter (DM). On each monitor farm 12 healthy lactating cows were selected for liver biopsy and collection of blood samples during the following autumn. Around the same time, livers were collected from 12 cull cows per farm when they were slaughtered, and samples of pasture were again collected from each farm. Concentrations of Cu were measured in all tissue samples.

RESULTS

Concentrations of Cu in pasture tended to be higher (mean 10.4 vs 8.2 mg/kg DM) in the autumn than spring, while concentrations of Mo were lower in the autumn (mean 0.35 vs 1.07 mg/kg DM). Most of the 24 farms used Cu supplementation in some form. Mean concentrations of Cu in liver for herds ranged from 640 (SD 544) to 2,560 (SD 474) micromol/kg fresh tissue in biopsies, and 520 (SD 235) to 2,610 (SD 945) micromol/kg in liver from cull cows. Mean concentrations of Cu in serum ranged from 7.9 to 13.4 micromol/L. The variability in concentrations of Cu for each farm was greater for liver (CV 50%) than serum (CV 21%). For individual cows, concentrations of Cu in liver, obtained by biopsy, and serum were not correlated.

CONCLUSIONS

The concentration of Cu in liver of dairy cows reflected widely differing dietary intakes of Cu between herds, although levels indicated an adequate Cu status on all farms in this study. Use of either biopsy samples or livers from cull cows were indicative of the Cu status of the herd. Wide variation in observed concentrations of Cu in liver indicated that at least 12 cows per herd should be sampled. On farms with intensive, long-term Cu supplementation programmes there is a risk of chronic Cu toxicity in some animals. Thus, the Cu status of dairy herds should be determined, and monitored, before making any recommendations regarding supplementation.

Haematolohical profile of subacute oral toxicity of molybdenum and ameliorative efficacy of copper salt in goats

Molybdenum toxicity produces a state of secondary hypocuprosis, resulting into alterations in normal hematological profile. In the present study, ammonium molybdate alone and with copper sulfate (II) pentahydrate (ameliorative agent) was administered orally for 30 consecutive days in healthy goats of group 1 and 2, respectively, to access the effect on the hematological profile on different predetermined days of dosing. Administration of ammonium molybdate alone produced significant decline in the mean values of hemoglobin (Hb), packed cell volume (PCV), total leukocyte count (TLC), total erythrocyte count (TEC), and mean corpuscular hemoglobin concentration (MCHC), with a significant increase in neutrophil level and mean corpuscular volume (MCV). However, values of erythrocyte sedimentation rate, mean corpuscular hemoglobin, and differential leukocyte count were not significantly altered. On comparing observations of ameliorative group with the group 1 goats, it is concluded that the ameliorative copper salt has beneficial effects in alleviating the alterations in the values of Hb, PCV, TLC, TEC, MCV, MCHC, and neutrophils.

The addition of high manganese to a copper-deficient diet further depresses copper status and growth of cattle

A study was conducted evaluating the effect of long-term Cu deficiency, with or without high Mn, on growth, gene expression and Cu status of beef cattle. Twenty-one Angus calves were born to cows receiving one of the following treatments: (1) 10 mg supplemental Cu/kg DM (+Cu); (2) no supplemental Cu and 2 mg Mo/kg DM ( - Cu); (3) - Cu diet plus 500 mg supplemental Mn/kg DM ( - Cu+Mn). Calves were weaned at approximately 183 d of age and individually fed throughout the growing and finishing phases. Plasma Cu was lower (P < 0.01) in - Cu calves compared with +Cu calves while high dietary Mn further depressed (P < 0.01) plasma Cu in - Cu+Mn calves v. - Cu calves. Liver Cu concentrations in +Cu calves were greater (P < 0.01) than in - Cu calves, with no differences between - Cu and - Cu+Mn calves. The daily body-weight gain of +Cu calves was greater (P < 0.01) than - Cu calves during the period from birth to weaning, but did not differ during the growing phase. - Cu+Mn calves gained less (P < 0.05) than - Cu calves during the growing phase. DM intake was lower (P < 0.01) in - Cu+Mn calves v. - Cu calves, and did not differ among +Cu and - Cu calves. The relative gene expression of cytochrome c oxidase in the liver was lower (P < 0.05) in - Cu calves compared with +Cu or - Cu+Mn calves. In conclusion, feeding a Cu - deficient diet in combination with high Mn negatively affected the growth and Cu status of beef cattle.

Copper deficiency in ruminants

Copper deficiency can reduce the productivity of livestock. The effect of copper deficiency on a number of copper enzymes and copper-dependent systems is discussed, to highlight the areas where their role needs to be clarified. Special reference is made to cytochrome c oxidase, lysyl oxidase, superoxide dismutase and endoplasmic reticulum enzymes and to their role in the expression of disease. The modification of microbiological insult by a change in superoxide dismutase activity without any other direct metabolic consequences is discussed, to introduce the concept of an external challenge being necessary before any effect of an otherwise sub-clinical copper deficiency is observed. The changes in activity of the various copper enzymes are described in clinical and experimentally induced copper deficiency in sheep and cattle, two species in which copper deficiency can have economic consequences. The diagnostic value of various blood markers, such as copper, caeruloplasmin and erythrocyte superoxide dismutase is discussed. The measured degree of hypocupraemia is related to different types of sampling (e.g. plasma or serum), physiological status (e.g. in the pre- and postpartum cow), changes that occur in the neonate, and also to the effect of the acute-phase reaction. The use of erythrocyte superoxide dismutase as a marker for the copper status of sheep and cattle is compared with more conventional markers such as plasma concentration of copper. The use of blood markers to map the extent and location of hypocupraemia (due to reduced copper intake or availability) among suckler (beef) herds in Northern Ireland is also discussed.

Anaerobic potentiation of copper toxicity and some environmental considerations

The toxicity of copper is substantially greater when the metal ions is applied to cells under conditions of anoxia than under aerobic conditions. The increase in toxicity occurs because Cu(II) is reduced to Cu(I) which is stable under anoxia and is more toxic than the oxidized species. This effect has been observed in mammalian cells in tissue culture and in bacteria. Anoxic potentiation of copper toxicity has also been observed in algal, fungal and yeast cells. The reduction of Cu(II) has been demonstrated by electron paramagnetic resonance spectrometry. The appearance of Cu(I) has been observed by means of specific colorimetric reagent. The reduction of Cu(II) to Cu(I) is not dependent upon concomitant metabolism and requires only a supply of sulphydryl groups. Microorganisms that are responsible for two anaerobic processes of economic importance to humans, the digestion of sewage sludge in effluent treatment plants and the digestion of food in ruminant animals, may be exposed to high concentrations of copper. The environmental consequences of this exposure are discussed.

Dietary sources of copper

The dietary intakes of copper by children and adults who consume free diets are often significantly lower than the recommended daily allowances of the National Academy of Sciences (USA) or the World Health Organization. These lower-than-recommended intakes of copper appear to be adequate for healthy individuals since states of copper deficiency have not been observed in the absence of an accompanying metabolic disorder. Copper deficiencies have arisen in pre-term infants of low birth weight as a result of breast-milk diets, and in children and adults as a result of fluids that are used for total parenteral nutrition. This paper describes the use of trace-metal balance studies to evaluate the adequacy of copper intake from these sources and from synthetic diets that are used in the treatment of inherited and acquired metabolic disorders.

Caeruloplasmin: a multi-functional metalloprotein of vertebrate plasma

Ceruloplasmin is a blue copper protein found in the alpha 2-globulin fraction of vertebrate plasma. It is a single-chain glycoprotein of molecular weight 132 000. It contains six copper atoms per molecule, comprising three or possibly four different types of copper. Its many functions may be related to the heterogeneous nature of these six copper atoms and to the various catalytic activities which they provide. Caeruloplasmin resembles albumin and transferrin in that all three serum proteins are regarded primarily as transport proteins. However, each has numerous other action as important as this transport function. Caeruloplasmin directly mobilizes iron into the serum and provides the major molecular link between copper and iron metabolism; it is the most prominent serum antioxidant, preventing deleterious oxidation of polyenoic acids and other substrates; it scavenges superoxide radicals; it serves as an acute-phase reactant (an endogenous modulator) of the inflammatory response; finally, caeruloplasmin may regulate the serum concentration of the biogenic amines, adrenaline (epinephrine) and serotonin (5-HT).

Metabolic interactions of copper with other trace elements

Metabolic interactions between copper and other trace elements influence not only the susceptibility of animals and humans to deficiency or toxicity of copper but also the biochemical and pathological consequences of these states. Antagonistic trace elements affect the utilization of copper by reducing its solubility within the intestinal lumen, by competing with copper during its absorption or transport, or by modifying its distribution between receptors in body tissues. The derangement of iron-dependent functions during the development of copper deficiency provides a further example of such interactions which, in this instance, arise from the involvement of copper in processes that apparently regulate the flux of iron between plasma and cellular pools. This paper deals with recent studies of the mechanisms of the interactions between copper and zinc, cadmium molybdenum and iron.

Copper, biogenic amines, and amine oxidases

Amine oxidases have been classified in the past on the basis of either (a) the structural requirements in the substrate or (b) the tissue (or species) of origin, or both. As knowledge about the chemistry of these enzymes grows, their classification on the basis of chemical structure is becoming possible. Currently, many amine oxidases can be categorized according to whether they contain riboflavin (e.g. the monoamine oxidases -- EC 1.4.3.4) or copper (e.g. the amine oxidases of plasma and the diamine oxidases EC 1.4.3.6 -- found prominently in pig kidney cortex, placenta, and pea seedlings). The copper-linked oxidases are inhibited by cyanide and by semicarbazide. The nature of the carbonyl compound(s) in the various enzyme molecules is not yet known. Nutritional deficiencies of copper and treatment of animals with copper-chelating agents are reflected in reduced activity of one or more of these enzymes. The ultimate effects of copper deficiency and copper excess on amine metabolism in vivo are described.

Therapeutic management of copper deficiency in buffalo heifers: Impact on immune function

To evaluate the magnitude of copper deficiency in Northern India and to examine the various haematobiochemicals, enzymes, vitamins and immune functions affected by copper deficiency, and to identify the parameters which can be of diagnostic importance in copper deficiency, a survey was conducted in 12 districts of Northern India. Significant deficiency of copper was observed in soil, fodder and serum samples of buffalo heifers. Fifty hypocuperaemic buffalo heifers were selected from these areas and were randomly divided into two groups, A and B. The heifers in group A were provided with mineral mixture containing copper sulphate and in group B without copper sulphate. Significant (p<0.01) improvement in serum ceruloplasmin level was observed within 30 days of treatment, while significant (p<0.01) improvement in monoamine oxidase and liver cytochrome oxidase was observed at the 60th day of treatment in group A animals. Significant improvement was observed in T(3) and T(4), in the animals of group A within 60 days of treatment. The values of vitamin A and E showed significant (p<0.01) improvement within 30 days of treatment. The phagocytic activity of neutrophils against Candida albicans significantly (p<0.01) improved in group A within 60 days of treatment. Similarly, significant improvement in superoxide dismutase activity in red blood cells was observed at the 30th day, and in total leukocytes and whole blood at the 60th day in group A animals. Significant improvement in liver copper level was observed at the 30th day of treatment, while in group B the liver copper was significantly (p<0.01) depleted at the 60th day of experimentation. Additional copper supplementation improved growth performance significantly in group A.

Impact of molybdenum on the copper status of red deer (Cervus elaphus)

AIM

To determine the effect of increasing molybdenum (Mo) intakes on serum and liver copper (Cu) concentrations and growth rates of grazing red deer (Cervus elaphus).

METHODS

Molybdenum- and Cu-amended fertilisers were applied to six 1.1-ha paddocks in a 3 x 2 design. Three levels of Mo were applied on two paddocks at each level in mid April (designated Day 1); levels were: none (control), 0.5 (medium) and 1.0 (high) kg Mo/ha as sodium molybdate. In late May (Day 39), two levels of Cu (none and 3.0 kg Cu/ha, as copper sulphate) were applied to each of the three levels of Mo-treated paddocks. Pasture Mo, Cu and sulphur (S) concentrations were measured at about fortnightly intervals. In late June (Day 74), ten 6-month-old red deer hinds were placed on the six experimental pastures, and serum and liver Cu concentrations were monitored at about monthly intervals for 102 days. The hinds were weighed on four occasions during the trial.

RESULTS

Mean pasture Mo concentrations on Day 56 were 2, 4.6 and 11.3 mg/kg dry matter (DM) for the untreated control, medium and high Mo-treated pastures, respectively. Pasture Cu concentration was 95 mg/kg DM on Day 59, 53 mg/kg DM on Day 90, and 9 mg/kg DM by Day 153. Mean S concentration in pasture was 3.3 (range 3.03-3.45) g/kg DM. Copper application to pasture had no significant effect on serum and liver Cu concentrations in deer so data were pooled within Mo treatment. Mean initial (Day 74) serum Cu concentration was 9.2 micromol/L. In the deer grazing the control Mo pasture, this increased to 10.3 micromol/L on Day 112, before decreasing to 6.4 micromol/L on Day 176. In deer grazing the medium and high Mo-treated pastures, mean serum Cu concentrations were 3.8 and 3.9 micromol/L, respectively, on Day 112, and 2.5 and 3.3 micromol/L, respectively, on Day 176. Mean initial (Day 74) liver Cu concentration was 131 micromol/kg fresh tissue. In the deer grazing the control Mo pasture, this declined to 120 and 52 micromol/kg on Days 112 and Day 176, respectively. In deer grazing the medium and high Mo-treated pastures, liver Cu concentrations decreased to 55 and 52 micromol/kg fresh tissue, respectively, on Day 112, and 21 and 20 micromol/kg fresh tissue, respectively, on Day 176. Mean serum and liver Cu concentrations were not significantly different between deer grazing the medium and high Mo-treated pastures, and were lower (serum p=0.003, liver p<0.001) in those groups than in deer grazing the untreated control pastures. No clinical signs of Cu deficiency associated with lameness were observed. Deer grazing pastures that had Mo concentrations >10 mg/kg DM had lower (p=0.002) growth rates (100 vs 130 g/day) than those on pastures containing <2.4 mg Mo/kg DM.

CONCLUSION

Increasing pasture Mo concentrations from 2 mg/kg DM to > or =4.6 mg/kg DM significantly reduced serum and liver Cu concentrations in grazing deer. Reduced growth rate was observed at pasture Mo concentrations >10 mg/kg DM.

Copper status and enzyme, hormone, vitamin and immune function in heifers

A survey was conducted in 10 districts of Northern India to record the copper deficiency in soil, fodder and serum samples. Significant deficiency of copper was observed in soil, fodder and serum samples of heifers. The copper deficient animals were listless, showed depigmentation of skin, stiff gait and were anaemic and diahorric. The purpose of the study was to evaluate the magnitude of copper deficiency in Northern India and to examine the various haematobiochemicals, enzymes, vitamin and immune function which are affected by the deficiency of copper, so as to identify the parameters which can be of diagnostic importance in copper deficiency. Forty hypocuperemic heifers were selected from these areas and were randomly divided into two groups A and B. The heifers in group A were provided with mineral mixture containing copper sulphate and in group B without copper sulphate. Significant improvement (P<0.01) was observed in the haemoglobin (Hb), total leukocyte count (TLC) and total erythrocyte count (TEC) level at the 30th day of treatment in the animals of group A. Significant (P<0.01) improvement in serum. Ceruloplasmin (Cp) level was observed within 30 days of treatment, while significant (P<0.01) improvement in monoamine oxidase and liver cytochrome oxidase was observed at the 60th day of treatment in group A animals. Regarding hormones significant improvement was observed in T(3) and T(4), in the animals of group A within 60 days of treatment. The values of vitamin A and E showed significant (P<0.01) improvement within 30th days of treatment. The phagocytic activity of neutrophils against Candida albicans significantly (P<0.01) improved in group A within 60 days of treatment. Similarly significant improvement in superoxide dismutase activity in RBC was observed at the 30th day, and WBC and whole blood at 60th day in group A animals. Significant improvement in liver Cu level was observed at the 30th day of treatment, while in group B the liver Cu was significantly (P<0.01) depleted at the 60th day of experimentation. Additional Cu supplementation improved growth performance significantly in group A.

Mortes súbitas em bovinos associadas à carência de cobre

Foi estudado um surto de morte súbita em bovinos no sul do Rio Grande do Sul. Nos animais necropsiados não foram observadas lesões macroscópicas ou microscópicas significativas. Para testar se as mortes súbitas teriam sido causadas por plantas tóxicas, 13 espécies de plantas foram coletadas e administradas a coelhos num total de 440 a 600 g/ kg de peso vivo num período de 7 dias. Os resultados foram negativos. Os teores de cobre no fígado dos bovinos foram muito baixos (3,6±1,6 ppm-base seca) sugerindo que as mortes foram causadas por deficiência de cobre. Cinco amostras de pasto, coletadas no local do surto, apresentaram teores normais de Cu (8,4±0,8 ppm-bs) e S (0,2%±0,03%-bs), mas altos teores de Fe (522±122 ppm-bs). Um grupo de 10 novilhas foi suplementado com Cu subcutâneo. Este grupo e um grupo controle foram mantidos em área similar à da ocorrência do surto. Teores séricos de Cu, S, Fe, Mo e ceruloplasmina foram determinados bimensalmente durante um ano de experimento. Os teores médios de Cu (1,76±1,06 a 10,34±3,1 µmol/l no grupo controle e 3,86±1,53 a 10,61±1,34 µmol/l para o grupo suplementado) e ceruloplamina (6,59±3,93 a 18,61±4,14 mg/l para o grupo controle e 10,35±5,48 a 32,49±6,05 mg/l para o grupo suplementado) foram significativamente maiores no grupo suplementado (P=0,0046 para o Cu e P=0,0001 para a ceruloplasmina), mas a maioria das amostras tiveram teores abaixo do normal em ambos os grupos. Houve uma correlação entre os teores de Cu e os de ceruloplasmina (r=0,67, P=0,05). Em ambos os grupos os teores séricos de Fe (40,09±5,22 a 78,48±28,23 µmol/l) estiveram acima dos teores normais. Amostras de forragens foram coletadas bimensalmente em sete pontos do campo onde ocorreu o surto para determinação de Cu, Mo, S, Fe e proteína. Os teores de Cu (1,36±0,56 a 4,76±1,15 ppm-bs) estiveram abaixo dos requerimentos. Os teores de Mo (0,17±0,06 a 0,96±0,47 ppm-bs) estiveram dentro da normalidade. Valores de S (0,21±0,04% a 0,5±0,17%) e Fe (172,92±62,64 a 437,24±205,44 ppm-bs) alcançaram, ocasionalmente, níveis tóxicos. Teores de proteína variaram de 7,77±2,6% a 13,16±3,02%. Seis amostras de água e 6 amostras de pasto submerso foram coletadas no fim do experimento quando o campo estava inundado. Altos teores de Fe (169, 23±83,49 ppm) e S (0,06±0,03%) foram encontrados na água. Os teores de Fe e S no pasto submerso foram de 469,5±218,28 ppm e 0,19±0,05%, respectivamente. Os resultados obtidos sugerem que as mortes súbitas foram causadas por deficiência de Cu. Três fatores parecem ser responsáveis pela deficiência de Cu: 1) altos teores de Fe na pastagem e na água; 2) ocasionalmente baixos teores de Cu na pastagem; e 3) ingestão de S acima dos requerimentos, devido aos teores ocasionalmente altos na pastagem e na água. O surto descrito é similar a outros surtos de morte súbita em bovinos descritos no sul do Rio Grande do Sul durante o inverno, que foram, também, associados a baixos teores de cobre no fígado. As regiões onde ocorre a enfermidade são caracterizadas por solos arenosos e ácidos com inundações freqüentes durante o inverno. Em solos ácidos periodicamente inundáveis o ferro é solubilizado e absorvido pelas plantas, diminuindo o conteúdo de Cu na forragem e aumentando os teores de Fe. Esta parece ser a maior razão para a deficiência de cobre na região.

Responses of lactating dairy cows to copper source, supplementation rate, and dietary antagonist (iron)

Forty-eight lactating Holstein cows were fed low-Cu diets with 500 mg of supplemental Fe/kg of dry matter (DM), a Cu antagonist, for a 30-d Cu-depletion period. After depletion, two Fe treatments (0 and 500 mg of Fe/kg of dietary DM) and five Cu treatments (2 x 5 factorial arrangement) were compared over 83 d. The Cu treatments were control (basal diet containing 8 mg of Cu/kg of DM) and either 15 or 30 mg of supplemental Cu/kg of dietary DM from either CuSO4 or Cu-lysine. Feeding 500 mg of supplemental Fe/kg of DM (in addition to basal dietary concentration of 140 mg Fe/kg) depressed liver Cu in the absence of Cu supplementation. Apparent Cu retention, estimated from Cu intake minus fecal Cu, was increased greatly by Cu supplementation immediately after the depletion period but declined to very low net retention by d 45 of the 83-d experiment. There were no differences detected between CuSO4 and Cu-lysine except a tendency over time for Cu-lysine to maintain higher plasma Cu, especially in the absence of the Fe antagonist.

Novel mitochondrial proteins and decreased intrinsic activity of cytochrome-c oxidase. Characteristics of swayback disease in sheep

Swayback disease (SD), a fatal neurological disorder affecting lambs and kids, is characterized by abnormal mitochondria and low cytochrome-c oxidase activity. The cytochrome-c oxidase content and activity and the protein composition of mitochondria isolated from the brains of SD lambs were investigated. Difference spectra analysis indicated that the cytochrome-c oxidase content of mitochondria from SD animals was lower than normal, and electrophoresis showed that when compared to mitochondria from normal animals, lipid-depleted mitochondria from SD lambs had a different protein composition, particularly, in the 40-55 kDa region. Polarographic studies, using cytochrome-c as substrate, confirmed low intrinsic activity of cytochrome-c oxidase within the mitochondria of SD lambs. These studies also showed that at low ionic strength, such mitochondria did not yield the expected characteristic biphasic Eadie-Hofstee plots.

Ultrastructure of hepatocytes in copper-deficient Sika deer (Cervus nippon Temminck)

The livers of 13 Sika deer (Cervus nippon Temminck) aged 4 to 9 years and suffering from copper deficiency (enzootic ataxia) were examined histologically, histochemically and by electron microscopy. In addition, the serum and liver copper concentrations, measured in three animals, were found to be low. Histologically, the hepatocytes exhibited cloudy swelling, and numerous haemosiderin deposits were seen in the hepatocytes and Kupffer cells. Staining with p-dimethyl amino-benzylidene-rhodamine revealed distinctly fewer copper granules than normal. Histochemically, 3,3'-diaminobenzidine-H2O2 staining revealed increased numbers of catalase-positive granules around nuclei. Electron microscopically, "giant" and bizarre-shaped mitochondria, irregular depression of the mitochondrial membrane, and fusion of cristae were noted. Disorders of copper-containing enzymes, including cytochrome oxidase, caeruloplasmin and monoamine oxidase, may have been responsible for the mitochondrial abnormalities.

Sudden infant death syndrome (SIDS): immunoglobulins and hypoxia

A body of opinion suggests that immunological overstimulation of the gastrointestinal and respiratory mucosa is involved in SIDS. The local stimulation of immunoglobulin concentration in the respiratory mucosa is said to be the consequence of an accentuated reaction to a trivial infection (1-4). One hypothesis is that an accentuated airways reactivity plays a key role in the events leading to SIDS and cites the final insult as oxygen lack, low oxygen stores, high oxygen usage and cardiorespiratory failure (5). We hypothesize that hypoxia and antioxidants exacerbate disorders of the paracrine interaction in the airways mucosa leading to overproduction of immunoglobulins. Administration of vitamin E above dietary needs to hypoxic chicks increased the immune response. The effects were considered synergistic in elevated production of immunoglobulins, and in their function as antioxidants (6). The oxygen lack, low oxygen stores, high oxygen usage and cardiorespiratory failure (5) are factors capable of provoking an overstimulated immune response in the respiratory mucosa. When levels of T-helper/inducer cells are maintained in AIDS patients' blood plasma, survival time is extended (7). This paper investigates the role of 1,25 (OH) 2D3 in suppression of T-helper/inducer lymphocyte activity in vitro (8,9,34,36), and the failure of activated pulmonary alveolar macrophages (PAM) to produce sufficient 1,25(OH)2D3 to inhibit beta-cell proliferation before differentiation to immunoglobulin secreting cells (4,36).

Bovine serum amine oxidase: some differences between chromatographically defined forms including sensitivity to inhibition by dithiomolybdate

1. Bovine serum amine oxidase (BSAO) forms, defined by DEAE-cellulose and hydroxyapatite chromatography, were shown to have different kinetic characteristics with p-dimethylaminobenzylamine as a substrate; there was also some variation in heat sensitivity. 2. The forms showed similar sensitivity to inhibition by aminoguanidine but there were differences with respect to dithiomolybdate. 3. The results also provided some support for the view that both subunits were active catalytically. 4. It is concluded that while the forms were interconvertible, the practice of pooling different chromatographic fractions may not be acceptable in all circumstances. 5. While inhibition by dithiomolybdate is of biochemical interest it is concluded that inhibition of BSAO by thiomolybdates is unlikely to play a role in the clinical syndromes which are common in cattle exposed to Mo in the herbage.

Season and location effects on serum and liver mineral concentrations of Senepol cattle on St Croix, Virgin Islands

Serum and liver concentrations of selected macro- and trace minerals were determined in Senepol cattle at 8 sites (4 each in a high and low rainfall region) during the dry and wet season on St Croix. At each site an average of 15 mature, lactating cows, grazing native grass/legume pastures without supplementation were blood sampled each season. Liver samples were collected (n = 51) at slaughter from mature animals originating from the same sites. A preliminary analysis indicated no differences in serum mineral concentrations between mature lactating cows and growing heifers. There were differences between sites for serum magnesium (Mg) (P < 0.001), copper (Cu) (P < 0.05) selenium (Se) (P < 0.001) and zinc (Zn) (P < 0.01) in the dry season, and for Cu (P < 0.01), iron (Fe) (P < 0.001) and Zn (P < 0.01) in the wet season. Higher (P < 0.001) serum concentrations of Mg, Cu, Fe and Zn were observed in the dry season, while Se was higher (P < 0.01) in the wet season. Liver concentrations of Cu and Fe were lower (P < 0.01) and liver molybdenum (Mo) (P < 0.001) and Se (P < 0.05) higher during the dry season. The seasonal differences in serum Cu, Se and Zn concentrations have not been observed in other studies in the Central American region. More than 50% of serum samples were deficient in phosphorus (P) regardless of season, and in Cu and Zn during the wet season. Mineral supplementation should be considered.

Trace element deficiencies in cattle

Deficiency of cobalt, copper, iron, iodine, manganese, selenium, or zinc can cause a reduction in production. Reduced production occurs most commonly when a deficiency corresponds to the phases of growth, reproduction, or lactation. Because of environmental, nutrient, disease, genetic, and drug interactions, deficiencies of single or multiple elements can occur even when the levels recommended by the National Research Council for these nutrients are being fed. Additionally, random supplementation of trace elements above National Research Council recommendations is not justified because of the negative interaction among nutrients and potential toxicosis. Evaluation of trace element status can be difficult because many disease states will alter blood analytes used to evaluate nutrient adequacy. Proper dietary and animal evaluation, as well as response to supplementation, are necessary before diagnosing a trace element deficiency.

An assessment of the copper status of dairy herds in the Waikato, Taranaki and Northland in spring and the effects of daily supplementation with copper sulphate

The copper status of dairy herds in the Waikato, Taranaki and Northland regions between 1 August and 30 September was assessed by copper determinations made on composite sera from ten cows in each herd. Comparisons were made between two major groups categorised as as received and supplemented. In the latter, the cows received 2.0-6.0 g/day of copper sulphate orally from late gestation to the end of lactation. Mean copper values were determined from pastures in Taranaki and Northland and from pastures from three soil types in the Waikato. The lowest were in Northland (134.3 micromol/kg) and the highest in Taranaki (173.3 micromol/kg). Calculated dietary available copper levels showed the lowest were from pastures grown on organic soils in the Waikato. These soils also had high molybdenum levels. Serum copper values as received were lowest in Northland (7.30 micromol/l), and were marginal for both Taranaki (9.91 micromol/l) and the Waikato (9.93 micromol/l). The levels in supplemented herds were considerably higher, i.e. from the Waikato 11.7 micromol/l and from Taranaki 11.5 micromol/l. When liver and serum copper levels from paired samples were compared there was a reasonable correlation (r = 0.64) but the standard deviation approximated the mean liver copper level, i.e. 155 +/- 141 micromol/l.

Dietary copper, simple sugars, and metabolic changes in pigs

Inadequate dietary copper is known to result in undesirable metabolic changes in rats and humans. Abnormal cardiac function, leading to sudden death, is a common finding when copper deficient rats are fed a 62% fructose diet. To further study the apparent mineral-carbohydrate relationship to cardiac physiology, 3 male and 3 female swine were randomly assigned to four groups (6 pigs per group) which were fed low copper (1.5 ppm) or copper supplemented (40 ppm) diets with 20% of calories from either fructose or glucose for 10 weeks. In agreement with results from other animal studies, copper deficient swine exhibited decreased plasma ceruloplasmin, erythrocyte superoxide dismutase and plasma lysyl oxidase activities and lowered serum copper. The copper deficient fructose group had the lowest aortic lysyl oxidase activity and hematocrit when compared to the other groups. The relative heart weight in the copper deficient fructose group was 93% greater than the other three dietary groups. The livers of copper deficient fructose fed pigs were also significantly larger. Two enzymes related to cardiac and hepatic function, aspartate and alanine aminotransferase were also measured. Copper deficiency significantly lowered alanine aminotransferase but there was no dietary effect on aspartate amino-transferase. The results of this project indicate that the pig is a sensitive model for the study of cardiovascular abnormalities which occur when fructose is consumed with a low copper diet.

Laboratory findings associated with abomasal ulcers/tympany in range calves

The etiology of abomasal ulcers/tympany was investigated in 48 animals from 36 ranches in Wyoming and Nebraska. Results indicate that subclinical trace mineral deficiencies of copper and/or selenium exist in the range cattle in west central Nebraska and Wyoming. Etiological agents most frequently incriminated by bacteriologic cultures and/or histopathic examination were Clostridium perfringens and Campylobacter species. Histopathologic evaluation of abomasums revealed 31 of 38 cases contained abundant gram-positive bacteria associated with the damaged abomasal mucosa. Campylobacter-like organisms were demonstrated in 9 of 38 cases using the modified Dieterle stain. Clostridium perfringens was isolated in 14 of 38 cases, and Campylobacter jejuni was recovered from 5 of 38 cases.

Dietary fructose exacerbates the cardiac abnormalities of copper deficiency in rats

Copper deficiency has been shown to result in severe cardiovascular lesions in several species of animals. The principal carbohydrate in the copper-deficient diet most often used with rats is sucrose, which is known to have adverse effects on carbohydrate and lipid metabolism and thus may contribute to cardiovascular disorders. These observations prompted experiments in which starch and fructose were substituted for sucrose in a copper-deficient diet, to see if the effects of the copper deficiency might be modified. In the hearts from rats fed copper-deficient diets with fructose or sucrose, there was marked, mostly ventricular hypertrophy, and mild to severe myocardial inflammation, degeneration, and fibrosis. Aneurysm of the left ventricle and pericarditis also were common. Hearts from the starch, copper-deficient groups were much less hypertrophic, and very few were affected by myocardial inflammation, degeneration, or fibrosis. Defects of elastin or other structures were not observed in the aortas or pulmonary or coronary arteries of any specimens.