The effect of molybdenum, iron and sulphur on copper metabolism and physiology of sheep

Four experiments were carried out to investigate the effects of the dietary antagonists molybdenum (Mo) or iron (Fe) on copper (Cu) metabolism and physiology of sheep. In experiment 1, dietary Mo or Fe was provided in diets of Charollais cross growing lambs to investigate the effects on Cu status and performance. Dietary Mo or Fe had no effect on lamb performance but there were significant effects on Cu status. Plasma copper (Pl-Cu) concentrations were significantly higher in lambs that received dietary Mo (P<0.001) and ceruloplasmin (CP) activities were significantly lower (P<0.01) in lambs that received dietary Mo. Dietary Mo significantly altered the CP:Pl-Cu ratio in addition to significantly reducing liver Cu concentrations. No clinical symptoms were observed. In experiment 2, the effect of dietary Mo or Fe on immune responses of Charollais cross growing lambs were investigated. Cell mediated and humoral immunity were not affected by dietary treatment despite liver Cu concentrations being significantly lower (P<0.001) in lambs fed dietary Mo. In experiment 3, dietary Mo or Fe was provided in diets to Charollais cross growing lambs to investigate the effects on Cu status and trace element accumulation in the pituitary, ovary, cerebellum and liver. In addition, effects on pituitary function and ovary morphology were investigated. Dietary Mo significantly (P<0.001) reduced Cu concentrations in the liver in addition to significantly increasing (P<0.001) Mo concentration in the liver and ovary. Dietary Mo was found to significantly increase retention of ACTH in the pituitary gland. There were no conclusive effects of dietary treatment on pituitary or ovary histology. In experiment 4, dietary Mo or Fe was provided in the diets of Scottish Blackface wethers to determine the effects on Cu status and hepatic CP mRNA expression. CP mRNA expression was found to be unaffected by dietary treatment. These studies confirmed that dietary Mo was a more potent antagonist on Cu metabolism and physiology in sheep than dietary Fe

Dairy cow copper status in molybdenum rich areas

Koppar (Cu) är ett essentiellt spårämne med flertalet funktioner hos idisslare men både över- och underutfodring kan ha negativa effekter på djurets hälsa och produktion. Utöver det interagerar Cu med andra mineraler i våmmen vilket minskar tillgängligheten av Cu i tunntarmen. En av de mest avgörande antagonisterna för kopparupptag är molybden (Mo) som tillsammans med svavel (S) binder till Cu och bildar olösliga komplex. Molybden överförs från jord till gräs vilket resulterar i höga molybdenkoncentrationer i foder som är skördat från molybdenrika jordar. Högplatåerna kring Falköping är ett sådant område och för att motverka den inhiberande effekten av Mo tillförs extra Cu till mjölkkofoderstater i området. Idag är leverprover den vanligaste metoden för att utvärdera kopparstatus, antingen från leverbiopsi eller från slaktade djur. En metod för att utvärdera Cu status som kan implementeras i rutinskötsel av mjölkkor i områden med molybdenrika jordar hade varit ett viktigt verktyg för att säkerställa korrekt utfodring av Cu. Målet med denna studie var därför att utvärdera och jämföra kopparstatus på mjölkbesättningar i Falköpingsområdet med höga och låga molybdenkoncentrationer i fodret. Fokus i detta masterarbete var på Cu som utsöndras via träck, urin och mjölk då dessa metoder skulle vara möjligt att genomföra som del av rutinskötsel i mjölkkobesättningar. 10 mjölkgårdar i Västra Götaland valdes ut för att delta i studien baserat på molybdenkoncentrationen i hemodlat grovfoder. 5 av gårdarna hade högt (HI) molybdeninnehåll (≥ 5 mg Mo/kg ts) och 5 av gårdarna hade lågt (LO) molybdeninnehåll (≤ 1.2 mg Mo/kg ts) i grovfodret. På varje gård provtogs 5 kor på träck, urin och mjölk. Proverna analyserades för kopparkoncentration. Utöver detta provtogs även allt hemodlat foder för mineralinnehåll och en endagars foderstatskontroll genomfördes för att skatta dagligt foderintag, inklusive mineraler. Kopparkoncentrationen i proverna jämfördes med intag samt analyserades för korrelationer. Kopparkoncentrationen i både träck (FCu) och urin (UCu) påverkades av intaget av Cu, dock inte av molybdenintaget. Kopparkoncentrationen i mjölk (MCu) påverkades varken av koppar- eller molybdenintag. Inga prover visade någon skillnad mellan gårdar som var HI eller LO, troligen till följd av lägre kopparutfodring än förväntat. Träckprov har i denna studie visat sig har störst potential för att användas som ett verktyg att utvärdera kopparupptag hos mjölkkor men vidare forskning är nödvändig för att bekräfta dess korrelationer med kopparstatus.Copper (Cu) is an essential trace mineral with several important functions in ruminants, but both under- and over feeding of Cu can have negative effects on the animals health and production. In addition, Cu interacts with other mineral elements in the rumen, which decrease the Cu availability in the small intestine. One of the major antagonists of Cu uptake is molybdenum (Mo) which together with sulphur (S) binds to Cu, forming insoluble complexes. Molybdenum is transferred from soil to crops which results in high Mo concentrations in feed harvested from Mo rich soils. The high plateaus around Falköping, Sweden, is an area with high Mo soils. To compensate for the inhibitory effect of Mo, extra supplementary Cu is included in the rations to dairy cows in the area. At present, the most common method for assessing Cu status is analysis of liver samples, either as liver biopsy or from slaughtered animals. A method for monitoring Cu status which could be implemented into routine management of dairy herds in high Mo areas would be an important tool to ensure correct supplementation of Cu. The objective of this study was therefore to evaluate and compare Cu status in dairy herds located in the area around Falköping, Sweden, with high or low Mo concentrations in the feed. Focus in this master thesis was on Cu excreted in faeces, urine and milk as these methods could be relatively easy to implement in routine management of dairy herds. 10 dairy farms in Västra Götaland, Sweden, were chosen for the study based on the Mo levels in their home grown forage. 5 farms had high (HI) levels of Mo (≥ 5 mg Mo/kg DM) and 5 farms had low (LO) levels of Mo (≤ 1.2 mg Mo/kg DM) in their forage. On each farm 5 lactating cows were sampled for faeces, urine and milk and the samples were analysed for Cu concentration. In addition, feedstuffs produced on the farm were analysed for mineral content and a one day feeding control was performed to estimate daily feed intake, including mineral intake. Sample Cu concentrations were compared with intake and analysed for correlations. Both faecal (FCu) and urine (UCu) Cu concentration was affected by intake of Cu but not intake of Mo. Milk Cu concentration (MCu) was not affected by intake of either Cu or Mo. In none of the samples a difference between HI or LO farms could be observed, probably because of lower Cu supplementation than expected on HI farms. Faecal samples had the highest potential for being a useful tool in monitoring of Cu status but further research is needed to confirm its correlations with Cu status

Detection and Treatment of Mineral Nutrition Problems in Grazing Sheep

Livestock Production/Industries,

The effect of excessive dietary calcium upon the absorption and utilization of selenium-75, molybdenum-99, copper-64 and iron-59 in swine

The objectives of this study were: 1. To determine the absorption and utilization of Selenium-75, Molybdenum-99, Copper-6H and Iron-59 when feeding excessive calcium to growing swine. 2. To further determine the distribution of the radioactive elements in the tissues of these animals. 3. To determine growth rate, feed consumption and feed efficiency when feeding excessive levels of calcium. These isotopes were selected for this study because of their properties, which made it possible to employ the multiple dosing technique . Se-75 and Mo-99 were used together because both are gamma emitters and Se-75 has a half-life of 120 days whereas Ho-99 has a halflife of 2.8 days. Likewise copper and iron were used simultaneously since Fe-59 has a half-life of 45.1 days and Cu-64 has a half-life of 12.8 hours and both are gamma emitters. Each of the samples could be counted twice and the short half-life isotope corrected for decay and determined by difference

Added dietary sulfur and molybdenum has a greater influence on hepatic copper concentration, intake, and performance in Holstein-Friesian dairy cows offered a grass silage- rather than corn silage-based diet

To test the hypothesis that the metabolism of Cu in dairy cows is affected by basal forage and added S and Mo, 56 dairy cows that were 35 (standard error ± 2.2) days postcalving and yielding 38.9 kg of milk/d (standard error ± 0.91) were offered 1 of 4 diets in a 2 × 2 factorial design for a 14-wk period. The 4 diets contained approximately 20 mg of Cu/kg of dry matter (DM), and had a corn silage-to-grass silage ratio of 0.75:0.25 (C) or 0.25:0.75 (G) and were either unsupplemented (−) or supplemented (+) with an additional 2 g of S/kg of DM and 6.5 mg of Mo/kg of DM. We found an interaction between forage source and added S and Mo on DM intake, with cows offered G+ having a 2.1 kg of DM lower intake than those offered G−, but no effect on the corn silage-based diets. Mean milk yield was 38.9 kg/d and we observed an interaction between basal forage and added S and Mo, with yield being decreased in cows offered G+ but increased on C+. No effect of dietary treatment on milk composition or live weight was noted, but body condition was lower in cows fed added S and Mo irrespective of forage source. We found an interaction between forage source and added S and Mo on milk somatic cell count, which was higher in cows offered G+ compared with G−, but not in cows fed the corn silage-based diets, although all values were low (mean values of 1.72, 1.50, 1.39, and 1.67 log10/mL for C−, C+, G−, and G+, respectively). Mean plasma Cu, Fe, and Mn concentrations were 13.8, 41.3, and 0.25 µmol/L, respectively, and were not affected by dietary treatment, whereas plasma Mo was 0.2 µmol/L higher in cows receiving added S and Mo. The addition of dietary S and Mo decreased liver Cu balance over the study period in cows fed either basal forage, but the decrease was considerably greater in cows receiving the grass silage-based diet. Similarly, hepatic Fe decreased more in cows receiving G than C when S and Mo were included in the diet. We concluded that added S and Mo reduces hepatic Cu reserves irrespective of basal forage source, but this decrease is considerably more pronounced in cows receiving grass silage- than corn silage-based rations and is associated with a decrease in intake and milk performance and an increase in milk somatic cell count

Copper poisoning, a deadly hazard for sheep

Copper (Cu) is an essential microelement for animals. However, sheep are particularly susceptible to Cu intoxication, a deadly disease reported worldwide. The risk of developing this poisoning is higher in vulnerable breeds and in intensively managed lambs or milk sheep. Two types of Cu intoxication can occur depending on the chronic or acute exposure to Cu. In chronic Cu poisoning (CCP), the most common form, Cu is accumulated in the liver during a subclinical period. A low intake of Cu antagonists (molybdenum, sulphur, iron, or zinc) favours Cu accumulation. The sudden release of Cu into the blood causes acute haemolysis with anaemia, haemoglobinuria, jaundice and death within 1–2 days. Acute Cu poisoning is related to the accidental administration or ingestion of toxic amounts of Cu. Acute oral exposure to Cu causes severe gastroenteritis, shock and death. Collapse and death occur shortly after parenteral administration. The diagnosis is based on history, clinical, gross pathological, histological and toxicological findings. Treatment of sheep with severe clinical signs often has poor success but is very effective during the Cu accumulation phase. Different therapies, based on either chelating agents or Cu antagonists, have been used to treat and prevent CCP

Copper metabolism in farm animals

hen a group of sheep were fed 1 gramme of copper sulphate daily there was no demonstrable effect on their blood copper levels. Three out of six may have shown a premonitary sign of poisoning in a form of photosensitisation. It was sixteen weeks before one died with the typical signs and. 'nost-mortem findings of copper poisoning, but this was followed by another in two weeks. Blood analyses indicated that there was a considerable rise of loosely- bound copper in the plasma in the terminal crisis.When two of the survivors were given 54 mg. molybdenum daily by mouth, their blood copper level rose while that of controls remained t7-! same. This increase was accounted for mainly in the plasma fraction but, in contrast to the findings in the haemolytic crisis of copper poisoning, the proportions of globulin-bound and loosely-bound copper remained approximately the same. The animals were not clinically affected and at the end of the period there was some evidence that their liver copper had been reduced. The distribution of copper within the liver was found to be different, in animals which had not died from copper poisoning, from that in animals which had.In a further experiment, five sheep were kept on a constant diet and their intake and output of copper was measured. 54 mg. molybdenum per day, given by mouth, was found to raise serum copper levels, depress urine copper and raise faecal copper output. The effect of 2.0 g. sulphate per day was to enhance these effects, but sulphate alone did not produce the same results. Post-mortem examination of the kidneys of two of these animals revealed tubular reabsorption of copper and damage to tubular epitheluim