The dentition of fallow deer (Dama dama): a scoring scheme to assess age from wear of the permanent molariform teeth

The sequence of tooth wear was determined from skulls of fallow deer of known age. A system for scoring molariform tooth wear has been devised so that small but readily recognizable wear changes of the individual cusps may be recorded and used to assess the age of animals of unknown birth dates. The technique can be readily adapted for other ruminant species with the appropriate database.     

Age assessment of fallow deer (Dama dama): from a scoring scheme based on radiographs of developing permanent molariform teeth

The stages of permanent tooth development observed in radiographs of the mandible were described for known-aged fallow deer Dama dama . Ten stages were defined and, by allocating scores for these stages, the scores that may be expected for a particular age have been identified. Lastly, the predicted age was given for total molariform scores. These were obtained, with 95% prediction intervals, from a regression of age on total molariform scores. An age assessment from tooth development stages can be made up to three years, after which, no further development takes place.     

Mineralization and wear of mandibular first molars in red deer (Cervus elaphus) of known age

The degree of dental wear was measured in 41 mandibular first molars from red deer of known age (range 2–18 years). The calculated wear indices were positively correlated with age ( r = 0.780, P < 0.001). In the same sample, significant ( P < 0.001) differences in hardness (determined by microhardness testing) were observed between enamel and coronal dentine as well as between outer and inner enamel and dentine, respectively. In animals belonging to the same age group (three-year-olds, n = 11), a negative correlation ( r = -0.830, P = 0.0016) was found between wear index and maximum mean enamel hardness. In a sample of five specimens from this age group, a negative correlation ( r = -0.918, P = 0.028) between maximum calcium concentration of enamel (measured by electron microprobing) and wear index was also recorded. We concluded that the intensity of enamel mineralization had a decisive effect on the degree of dental wear. Measuring of enamel hardness and subsequent modification of wear scores or indices is therefore recommended for future studies on the relationship between age and the degree of dental attrition in deer.     

Malignant melanoma in a captive red deer (Cervus elaphus elaphus)

We report a case of malignant melanoma in a captive red deer (Cervus elaphus elaphus). The primary lesion was on the plantar aspect of the right pastern and infiltrated the surrounding skin, but not underlying tendons or bone. Diffuse metastasis to the regional lymph nodes had occurred. Histologically, lesions were characterized by large numbers of variably pigmented epithelioid cells with a high degree of nuclear atypia and many mitotic figures. This is the first reported case of this neoplasm in red deer.     

Mitochondrial DNA phylogeography of red deer (Cervus elaphus)

In order to understand the origin, phylogeny, and phylogeography of the species Cervus elaphus, we examined the DNA sequence variation of the mitochondrial cytochrome b gene of 51 populations of deer from the entire distribution area of Cervinae with an emphasis on Europe and Asia. Several methods, including maximum parsimony, maximum likelihood, and nested clade analysis, revealed that red deer originated from the area between Kyrgyzstan and Northern India. We found two distinct groups of red deer: a western group consisting of four subgroups and an eastern group consisting of three subgroups. Our mtDNA data do not support the traditional classification of red deer as only one species nor its division into numerous subspecies. The discrepancies between the geographical pattern of differentiation based on mtDNA cytochrome b and the existing specific and subspecific taxonomy based on morphology are discussed.     

Physiological effects of hunting red deer (Cervus elaphus).

When red deer (Cervus elaphus) were hunted by humans with hounds the average distance travelled was at least 19 km. This study of 64 hunted red deer provides the first empirical evidence on their state at the time of death. Blood and muscle samples obtained from hunted deer after death were compared with samples from 50 non-hunted red deer that had been cleanly shot with rifles. The effects on deer of long hunts were (i) depletion of carbohydrate resources for powering muscles, (ii) disruption of muscle tissue, and (iii) elevated secretion of beta-endorphin. High concentrations of cortisol, typically associated with extreme physiological and psychological stress, were found. Damage to red blood cells occurred early in the hunts; possible mechanisms are discussed. Taken together, the evidence suggests that red deer are not well-adapted by their evolutionary or individual history to cope with the level of activity imposed on them when hunted with hounds.     

Successful in vitro production of embryos in the red deer (Cervus elaphus) and the sika deer (Cervus nippon)

The aim of our study was to define the conditions for IVM and IVF of oocytes in 2 common deer species as models for endangered related subspecies. Immature oocytes were recovered during the breeding season from postmortem ovaries (red deer) or by repeated laparoscopic follicular aspiration (sika deer). Oocytes were cultured for 24 h in IVM medium supplemented with EGF or FSH and follicular fluid. Stag semen was collected by electroejaculation (both species) or by epididymal flushing (red deer) and cryopreserved. For IVF, oocytes were exposed to different concentrations of thawed spermatozoa in a modified Tyrode albumin lactate pyruvate medium supplemented with 20% (v/v) estrus sheep serum for 18 h. After IVF, presumptive zygotes were allowed to develop in vitro for 7 days in synthetic oviduct fluid (SOF) supplemented with fetal calf serum (10%, v/v). In both species, the presence of ovine FSH and follicular fluid improved the in vitro maturation rate. In the sika deer, the optimal sperm concentration for IVF was 10(6)/mL and some fertilized oocytes reached the early morula stage (20 to 25 cells). In the red deer, after IVF with ejaculated or epididymal spermatozoa (2.0 x 10(6)/mL), 20% of zygotes developed to the blastocyst stage (50 to 80 cells).     

Chlamydiosis: seroepidemiologic survey in a red deer (Cervus elaphus) population in Italy

Chlamydiae are obligate, intracellular, gram-negative bacteria that are responsible for important diseases in humans, other mammals, and birds. Studies have shown that chlamydiae could be present in wild ruminants, but the serodiagnostic method most commonly used did not allow identification of chlamydial species. We determined the prevalence of antibodies to Chlamydia pecorum, Chlamydia suis, Chlamydia abortus, and Chlamydia psittaci in 271 red deer (Cervus elaphus) of a central Italian population, by using the microimmunofluorescence test that shows antibody response against genus-specific and species-specific antigens. No sera had detectable antibodies to C. pecorum and C. abortus. Antibodies were detected against C. psittaci (9.6%) and C. suis (3.3%). Antibody response could be related to contact of the red deer with birds and wild boars (Sus scrofa), respectively, and confirm an extended host range of individual Chlamydia species. In view of the potential zoonotic risk related to exposition of C. psittaci, our findings suggest surveillance of wild ruminants as potential reservoirs for chlamydiae.     

Reproductive seasonality in female Iberian red deer (Cervus elaphus hispanicus)

This study characterized the seasonal pattern of luteal cyclicity in Iberian red deer (n=16), by measuring plasma progesterone concentrations in hinds (female red deer) twice per week from calving (May and June) 1996 until May 1997. In eight of these hinds we also examined plasma prolactin profiles to assess seasonal responses to photoperiod. Plasma progesterone concentration in the 16 hinds studied indicated that the reproductive pattern is seasonal, and lasts for 5.73 +/- 0.27 months. After calving, progesterone levels remained basal (no luteal activity) for several months, except in a hind that lost her calf just after calving, and thus did not have to suckle it. This hind showed two consecutive estrus cycles in the month following calving, which suggests that suckling has an inhibiting effect on the resumption of ovarian activity. These results also showed that as long as the hinds do not become pregnant, they show between 5 and 10 estrus cycles per reproductive season (8.06 +/- 0.35), ranging between 105 and 249 days from onset of the first cycle to end of the last one. Uninterrupted cycling lasted for 3.5-6.4 months (mean, 4.6 +/- 0.24). Cyclic luteal activity was found from October to February in all hinds, with a smaller, but notable proportion in September (56.25%) and March (68.8%), whereas it was negligible in the remaining period. Our results show a reproductive season similar to or longer than that recorded by other authors. Prolactin plasma concentrations showed a yearly trend following that of photoperiod, with peak concentrations from April to July, a decrease in August, minimal concentrations from September to February and a sharp increase in March.     

Artificial insemination of red deer (Cervus elaphus) with frozen-thawed wapiti semen

Semen collected from wapiti (Cervus elaphus) in Canada in 1983 was frozen in two extenders. In 1988, the semen was used to inseminate 200 red deer hinds on 2 farms in New Zealand. Oestrus was synchronized in the hinds with progesterone-impregnated intravaginal devices (CIDR); 200 iu pregnant mares' serum gonadotrophin was given to each hind on Day 11. The CIDRs were removed on Day 12 at 20/h, as the numbers of the hinds were recorded. On Day 14, 54-56 h after CIDR removal, the hinds were brought into the yards in the same batches and laparoscopically inseminated. Semen from three sires was used. The overall conception rate was 51%. Gestation length ranged from 239 to 247 days. One hind was lost at calving, 3 calves had to be hand raised and there were 2 neonatal calf deaths.     

Genetic roots of the red deer (Cervus elaphus) population in Eastern Switzerland

Overhunting of red deer (Cervus elaphus) in eastern Switzerland led to its extinction in the second half of the 17th century. Natural recolonization must have taken place later, because red deer were seen again in the canton of the Grisons (eastern Switzerland) in the 1870s. According to historical data, three different populations could have served as the source population. To determine the genetic origin of the eastern Swiss red deer population, we collected samples from five different subpopulations in the canton of the Grisons as well as from four adjacent populations in Germany, Liechtenstein, Austria, and Italy. We analyzed the samples by genotyping 18 microsatellite loci. F(ST) values, assignment tests, correspondence analysis, and fuzzy clustering clearly pointed to Liechtenstein as the most probable source population for the red deer in eastern Switzerland. In addition, our analyses revealed high gene diversity in all examined populations. Gene flow and the high genetic admixture are discussed.     

Seasonal luteal cyclicity of pubertal and adult red deer (Cervus elaphus)

Reproductive failure of rising-two-year-old (R(2)) hinds and seasonal misalignment between calving and pastoral feed production are two factors limiting reproductive productivity of farmed red deer hinds in New Zealand. This study aimed to better understand processes around female puberty and breeding seasonality by describing the potential breeding season (i.e., oestrous cyclicity) of three red deer genotypes. A total of 27 hinds born in December 2005, representing Eastern European (Cervus elaphus hippelaphus), Western European (C.e. scoticus) and F1 crossbred (C.e. hippelaphus×scoticus) red deer, were blood sampled thrice-weekly for 7-8 months (February-September/October) across two years spanning the potential breeding seasons as R(2)'s in 2007 (i.e., puberty) and as adults in 2008. Plasma progesterone profiles were used to construct breeding cycle histories for each hind. Four R(2) hinds failed to initiate oestrous cycles (i.e., puberty failure). The remaining R(2) hinds, including all F1 hinds, exhibited between two and seven oestrous cycles. F1 hinds were significantly earlier to initiate, and later to terminate, cyclic activity, resulting in a longer mean pubertal breeding season (139 days) than for Eastern (86 days) and Western hinds (86 days). However, the data for R(2) hinds are confounded by live-weight, with the F1 hinds being significantly heavier than other genotypes. There were significant correlations between live-weight and seasonality parameters in 2007. All hinds were cyclic as adults in 2008, exhibiting between four and nine oestrous cycles, and a mean breeding season duration of between 132 (Western) and 137 (F1) days. For adult hinds there were no significant genotype differences in cyclic onset and cessation timing, and no observable relationships between live-weight and any reproductive parameter. However, the mean dates for the onset of the breeding season for all genotypes in 2008 were 2-3 weeks later than normally expected for adult hinds in New Zealand. The reasons for this are unclear but may relate to chronic stress of frequent animal handling. The study has demonstrated that puberty in red deer hinds is associated with a shorter potential breeding season than for adult hinds, and that perturbation of breeding activity appears to be quite common, leading to incidences of puberty failure and possibly other aberrant cyclic events. Live-weight×genotype interactions may influence puberty but do not appear to be strongly expressed in adults. However, the relatively late onset of oestrous cyclicity in the adult hinds may be an artefact of the study that has masked genetic influences on seasonal breeding patterns.     

Nocturnal hypometabolism as an overwintering strategy of red deer (Cervus elaphus)

Herbivores of temperate and arctic zones are confronted during winter with harsh climatic conditions and nutritional shortness. It is still not fully understood how large ungulates cope with this twofold challenge. We found that red deer, similar to many other northern ungulates, show large seasonal fluctuations of metabolic rate, as indicated by heart rate, with a 60% reduction at the winter nadir compared with the summer peak. A previously unknown mechanism of energy conservation, i.e., nocturnal hypometabolism associated with peripheral cooling, contributed significantly to lower energy expenditure during winter. Predominantly during late winter night and early morning hours, subcutaneous temperature could decrease substantially. Importantly, during these episodes of peripheral cooling, heart rate was not maintained at a constant level, as to be expected from classical models of thermoregulation in the thermoneutral zone, but continuously decreased with subcutaneous temperature, both during locomotor activity and at rest. This indicates that the circadian minimum of basal metabolic rate and of the set-point of body temperature regulation varied and dropped to particularly low levels during late winter. Our results suggest, together with accumulating evidence from other species, that reducing endogenous heat production is not restricted to hibernators and daily heterotherms but is a common and well-regulated physiological response of endothermic organisms to energetically challenging situations. Whether the temperature of all tissues is affected, or the body shell only, may simply be a result of the duration and degree of hypometabolism and its interaction with body size-dependent heat loss.