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Signs of clinical copper deficiency in ruminant animals include infertility. Blood copper concentrations alone are not an adequate indicator of copper status, as they take no account of the thiomolybdate challenge to the animal. The use of the ratio of caeruloplasmin activity to plasma copper concentration should provide a better indicator of molybdenum induced copper problems. The objectives of this study were to obtain veterinary feedback on the University of Leeds Trace Element Laboratory's (ULTEL) assessment of copper status and responses to any recommended supplementation. Blood samples from 713 female cattle from 114 herds were assessed for copper status, including plasma copper concentrations, serum caeruloplasmin activities and the ratio between the caeruloplasmin and plasma copper (CP/PlCu ratio). On the basis of only plasma copper analysis 95.0 % of the cattle were classified as being of normal copper status using Veterinary Laboratory Agency reference ranges. However, when the CP/PlCu ratio was also considered only 35.6 % of the cattle would be classed as having normal copper status. Appropriate copper supplementation would be required by 30.7 % of the cattle and a further 27.8 % could also benefit from additional copper. Veterinary responses to a questionnaire (80 % returned) indicated that infertility was a major problem in their clients’ herds. Where copper supplementation was recommended and administered an increase infertility was observed. In herds showing poor or lack ofoestrous behaviour/ later embryo loss (signs of clinical copper deficiency), 91.7 % reported that these signs were reduced by copper supplementation. The relevance of the CP/PlCu ratio as a diagnostic aid in the identification of copper responsive infertility has been supported by the responses of the veterinary surgeons.

The soluble glass bolus was more effective at 16 weeks after administration than the copper oxide needles. However, the treatments were similar at 20 weeks in supplying extra copper to red deer at pasture. The bolus also provided effective selenium supplementation. The equivocal vitamin B12 results indicate caution in using this parameter to assess cobalt status in this species until further evaluated.

Over the 10-week duration of the trial, the bolus gave the best maintenance of copper status and correction of clinical copper deficiency by preventing uptake of free tetrathiomolybdate into the sheep. The needles and injection also corrected the clinical copper deficiency, with the injection increasing the plasma copper and caeruloplasmin more, whilst the needles were better when the CP/PlCu ratio and TCA insoluble copper were assessed. The chelate was better than the drench for copper status although neither could sustain the correction of the clinical deficiency.

SIR, — We refer to the short communication by [Laven and others (2006)][1]. This reinterprets the data of [Scaletti and others (2003)][2] and questions why copper supplementation did not affect the caeruloplasmin:plasma copper ratios. However, there is an alternative interpretation of this data

Secondary copper deficiency in ruminant animals is induced by high dietary levels of molybdenum (Mo), iron (Fe) or sulphur (S). Within the rumen, sulphur reacts with Mo to form a series of thiomolybdate molecules (TM) which may chelate copper. This reduces copper absorption or if TM is absorbed, inhibits copper metallo-enzyme activities. Parental administration of TM has resulted in an increase in Cu to the brain and an increase in Mo to the pituitaries (Haywood et al., 1998). This redistribution may alter neurological, endocrine and reproductive function. However, there are no reports on effects of endogenously produced TM on brain or pituitary trace element accumulation. The objective of this study was to determine the effect of dietary Mo or Fe on copper status and mineral retention in the pituitary gland and ovary of growing lambs.

Clinical copper deficiency is the second most common mineral deficiency in the world, the main cause being high dietary levels of molybdenum, sulphur and iron. Phillippo et al, (1987) reported that clinical signs of deficiency resulted from high dietary Mo and S. However, Fe and S resulted in hypocupraemia but did not induce clinical signs of deficiency. Therefore is was concluded that clinical copper deficiency was due to a direct effect of dietary Mo and S on copper metabolism in ruminants. Mackenzie et al. (1997) reported that plasma copper levels were not an accurate indicator of copper status and unlikely to predict animals requiring copper supplementation. Caeruloplasmin is large copper enzyme and accounts for 88% of plasma copper and Mackenzie et al. (1997) proposed that a caeruloplasmin to plasma copper ratio may provide a more accurate biochemical indicator of copper status. This trial was designed to investigate the effect of dietary Mo, S and Fe on the copper status of the lambs.

Many sheep in the United Kingdom are grazed on pastures deficient in cobalt and selenium. Proprietary products for selenium and cobalt supplementation often contain copper, which in certain breeds can induce copper toxicity. A soluble glass bolus has been manufactured to supply long term sustained release of cobalt and selenium similar to the commercially available Cosecure, but with the copper content being replaced by zinc. Sub clinical zinc deficiency has been suggested to be involved in disease conditions such as broken mouth periodontitis, footrot and mastitis. Therefore a long term continuous supply of zinc may be beneficial in these situations. This trial was designed to examine the effect of administering a zinc, cobalt and selenium soluble glass bolus on trace element status of over-wintered ewe lambs.

Increasing importance of home grown proteins has resulted in a renewed interest in grass-clover mixed swards. The objective of this experiment was to asses the effect of wilting on effluent production levels, polluting potential of the silage effluent, and silage quality in grass and grass-clover mixed swards.Perennial rye grass (G) and a grass clover mixed sward (0.75 perennial ryegrass, 0.25 white clover, GC) was cut in mid may. The G and GC was then precision chopped and ensiled in experimental silos at 0, 24 and 48 hours following cutting, with 5 replicate silos of each silage being made at each time period. The silage effluent was collected, the quantity produced was recorded and the biochemical oxygen demand and the chemical oxygen demand was measured. The silage was allowed to ferment followed by which the silage was sub-samples and composite samples 3 of each silage were analyzed for dry matter content, crude protein levels, neutral detergent fibre, water soluble carbohydrate, pH, lactic acid, acetic acid, proprionc acid, butyric acid, total volatile acid levels. The data were analyzed using the general linear model ANOVA in Minitab.

The commercial rearing of llamas in the UK is of increasing interest but there is little information on their trace element status especially regarding copper metabolism. Previous work on a closely related species, the Alpaca (Lama pacos) has shown them to utilise copper less efficiently than sheep (Grace et al., 1994). As llamas are grazed on marginal or improved pastures they may become susceptible to copper deficiency (thiomolybdate toxicity). However, evidence also shows that llamas can suffer from copper toxicity (Junge and Thornburg, 1989). Therefore diagnosis of trace element status is needed prior to nutritional supplementation.

A progesterone binding protein was characterized in the cytosol of human myometrium. The receptor sedimented in the 4S region on sucrose gradients and had an equilibrium dissociation constant of 3.7 times 10-9M. Synthetic progestagens had an affinity equivalent to that of progesterone while cortisol had low affinity for the binding protein. These same progestagens showed very low binding to human CBG. In normally cycling women, the total levels of cytosol receptor were higher during the follicular phase than during the luteal phase. Subjects taking oral contraceptives and those who were pregnant had the lowest concentration of myometrial progesterone receptor. Postmenopausal women had levels of myometrial receptor lower than those of the secretory phase of the cycle. Estrogen therapy increased the receptor concentrations of the menopausal myometrium to those of the proliferative phase. The estradiol receptor levels of myometrial cytosol revealed similar changes in cycling women. When both binding proteins were measured concurrently in the same specimen, there was a significant positive correlation.

The effects of trace element deficiencies in lambs, particularly zinc, copper, cobalt and selenium, include decreased growth rates and increased mortality. However, trace element supplementation of sheep reared under extensive conditions has several logistical problems.Two trials were designed to investigate the effect of a zinc, cobalt and selenium soluble glass bolus on the trace element status of out-wintered ewe lambs. In trial 1 600 8-month-old ewe lambs (500 Scottish Blackface and 100 North Country Cheviots) were allocated to two treatment groups; 300 were treated with a zinc, cobalt and selenium soluble glass bolus (zinc) and 300 were untreated (control). In trial 2, 315 8-month-old Scottish Blackface ewe lambs were allocated to three treatments: 105 were treated with the zinc, cobalt and selenium soluble glass bolus (zinc), 105 were treated with a copper, cobalt and selenium soluble glass bolus (copper) and the remaining 105 were untreated (control). Blood samples were collected immediately prior to giving boluses and again after approximately 4 months. These were assessed for zinc (plasma zinc concentration), cobalt (serum vitamin B12concentration), selenium (erythrocyte glutathione peroxidase activity) and copper status (plasma copper concentration, caeruloplasmin, amine oxidase and superoxide dismutase activity and calculation of the ratio between the caeruloplasmin and plasma copper).The zinc bolus in both trials significantly increased the plasma zinc concentrations (P< 0·001 andP< 0·01 respectively), erythrocyte glutathione peroxidase activities (P< 0·001) and serum vitamin B12concentrations (P< 0·001). The copper bolus also significantly increased the erythrocyte glutathione peroxidase activities (P< 0·001) and serum vitamin B12concentrations (P< 0·001) when compared with the controls but were not significantly different from the zinc group. The copper bolus significantly increased all of the copper status indicators (P< 0·01) when compared with the control and zinc groups. However, in trial 1 when only the zinc and control groups were compared, the zinc bolus significantly increased the ratio (P< 0·001) and serum caeruloplasmin (P< 0·001) and erythrocyte superoxide dismutase (P< 0·01) activities. These responses were not observed in trial 2 with the erythrocyte superoxide dismutase being significantly reduced in the zinc group when compared with the control group (P< 0·001).The zinc, cobalt and selenium soluble glass bolus increased the status of all three trace elements consistently for a period of at least 100 days. The increases of cobalt and selenium status were similar to those achieved using the copper, cobalt and selenium bolus, which also increased the copper status of the sheep.