Acta Veterinaria Scandinavica 2008, 50:8 http://www.actavetscand.com/content/50/1/8 sitological examination were collected quarterly throughout the years 1999–2002, each sampling includ- ing 4–8 animals from different age groups. The samples were analysed for parasite eggs and oocysts using sugar flotation, and for lungworm larvae after baermannisation. The mean serum Cu concentrations of the animals in the herd at different time points from January 2000 to Sep- tember 2002 are summarized in Table 1. The Cu concen- tration increased from a low level in January 2000 to an adequate level in March and May following the Cu-treat- ment in January and March. The mean serum Cu concen- tration, with no additional Cu treatments, again fell to a low level by September 2000. Levels returned to normal by January 2001 after Cu-treatment in September and November 2000. Following treatment in January and May 2001, and the daily feeding of Cu-enriched concentrates from May 2001, the mean serum Cu concentration of the herd appeared adequate when measured in September 2001, and in May and September 2002. In January 2000, the weights of adult hinds and calves (Table 1) were low and ultrasound scans revealed only 23% as pregnant. Following Cu treatment in January and March 2000, markedly bettered body condition and hair coat of the animals were observed. The weight gain in adult hinds and calves from January to April 2000 was 10% and 26% respectively. Another remarkable feature that occurred following this Cu treatment was that several hinds came into oestrus out of season and were covered, resulting in calving in November and December 2000. Two fully developed newborn calves were found dead in the enclosure whilst a third calf was found alive in the moribund state. The weight gain of the animals during summer 2000 was, in spite of good grazing conditions on luxuriant cultivated pasture, not satisfactory and the mean weights of calves and adult hinds in January 2001 were only 5% and 11% respectively higher than those seen in January 2000. The percentage of hinds found to be preg- nant in January 2001 was 46%. During the summers of 2001 and 2002 the weight gain in the herd was good, and the mean weights of calves and adult hinds in January 2002 and 2003 were 59% and 29% respectively above the level in January 2000. The reproductive success also improved remarkably, with 90% of hinds scanned in Jan- uary 2002 and 2003 being pregnant. Faecal parasitologi- cal examinations of the animals in the herd revealed only low to moderate counts of parasite eggs and oocysts, and of lungworm larvae. The findings in the herein reported red deer were consist- ent with unthrift related to a general Cu-deficiency in the herd, as reported in other studies [2-5]. Whether this defi- ciency was a result of an inadequate concentration of Cu in the diet (primary deficiency), or a result of dietary excess of antagonists (Mo, Fe, Zn, S), interfering with the utilization of Cu (secondary deficiency) [1], could not be determined. Specific syndromes of disease, i.e. enzootic ataxia and osteochondrosis, that have previously been reported in Cu-deficient red deer herds in Norway [9,15], were not observed. Whether the cases of diarrhoea seen in the present study were related to Cu-defiency remains an open question. However, diarrhoea of uncertain patho- genesis has been associated with Cu-deficiency in domes- tic ruminants [1]. The low rate of pregnancy observed in January 2000 was presumably an indirect effect of Cu deficiency, linked to the low body weights of hinds. No evidence of reproduc- tive failure associated with specific Cu-mechanisms has been reported in domestic ruminants [1], and good nutri- tional status of deer hinds prior to mating is essential to achieve not only high fertility but also a concentrated calv- ing season [16]. The Cu supplementation that was carried out in January and March 2000 resulted in general weight gain of hinds, and conception of several hinds in late spring, which is highly unusual. Other results of Cu sup- plementation seen in the present study included growth response in calves, and improved coat quality. These are all well known effects reported in several studies of Cu supplementation in deficient deer herds [3-5]. The liver concentrations of Se found in the red deer in the present study were above the minimum concentration considered to be adequate in domestic ruminants [1]. However, there are strong indications that both Cu and Se are trace elements of concern in Norwegian red deer farm- ing. Deficiencies or marginal concentrations of both ele- ments have been found in many farms having submitted liver samples for the control of trace element status to the National Veterinary Institute, and have also been demon- strated in fallow deer (Dama dama), moufflon (Ovis aries musimon) and moose (Alces alces) held in parks in this country (Unpublished data). In the present study, the oral treatment with CuO capsules increased the Cu concentration in serum to within ade- quate levels, but only for a relatively short time-period. Between March and September 2000, when no capsules were given, the serum Cu concentration again dropped to inadequate levels. This should also be seen in connection with the use of cultivated grass pastures during summer; rapidly-growing grass is known to be poor in Cu [17]. This drop in serum Cu concentration during the main period of growth and weight gain over the summer presumably contributed to the low body weights found in January 2001. For maintenance of adequate serum levels with a diet low in Cu, it seemed that CuO capsules need to be given at intervals of a few months. This is in accordance with observations reported in other studies [3,18,19]. The Page 3 of 4 (page number not for citation purposes)