Estimate and production of milk energy in two subspecies of red deer: Cervus elaphus hispanicus and C. e. scoticus

This study estimates the caloric value of red deer milk as assessed relating bomb calorimetry data with the main milk nutrients. The study also examines milk energy estimates and lactation variables to compare Iberian red deer hinds (Cervus elaphus hispanicus) and the most studied Scottish red deer (C. e. scoticus). The final model predicted energy value (Ecal) in kcal/g of fresh milk from fat (F) and protein (P) content of milk, but not lactose: Ecal = 0.345 + 8.332 F + 5.403 P. Energy content per gram of milk increased with lactation stage but there was no difference between subspecies. However, subspecies differed in the daily and total energy production. Although milk energy values appeared to differ with estimates following the most used model developed from livestock, milk energy of deer estimated by both methods showed a very high correlation with each other, and both yielded also similar correlation coefficients with the remaining lactation variables. Calf gains showed a greater correlation with mean protein content and total protein yield, than with total energy yield or other milk nutrients. Milk protein appears to be more relevant to calf growth than gross energy yield.     

Lactation under induced five-month delay reproduction in Iberian red deer (Cervus elaphus hispanicus)

In Iberian deer, calf birth date affects both milk production and composition, as well as the weight change of hind during lactation and calf growth. This study examines a five-month induced delay in calving (autumn group) in a group of 19 Iberian hinds compared to a group of 13 standard calving hinds (spring group). Fertility in the autumn group was half that of the spring one. From the former, a further two calves out of six died before or soon after birth. Successfully lactating hinds showed a greater concentration in protein, fat and lactose (P < 0.001), but did not differ from spring group in total milk yield, calf gain or weight change of hinds during lactation. However, after correcting for the greater calf or hind body weight at calving of the autumn group, this group showed lower values for these variables than the spring group. Results show that at least in Iberian deer, counter-season reproduction is possible, and that the effects on lactation variables are similar to those of a natural delay in calving.     

Effect of reproductive rest on the subsequent breeding in Iberian red deer hinds (Cervus elaphus hispanicus)

The objective of this study was to examine the effects of reproductive rest during the preceding year on subsequent breeding in captive Iberian hinds. To achieve this, influences were assessed on hind weight at mating, precalving and postcalving weight, hind body condition at mating, hind weight gain during gestation, hind weight loss at calving, total milk yield and calf birth weight during the following breeding season. Sex ratio was examined according to hind age class (sub-adults or adults), precise age, body condition and weight at mating, and reproductive rest. One hundred and twenty seven gestations and their subsequent lactations were analyzed in pluriparous Iberian red deer (Cervus elaphus hispanicus) kept in captivity for two years. Sixty four of these gestations (50.4%) took place after no gestation during the preceding year.Hinds that did not gestate the preceding year were heavier at mating and after calving, gained less weight during gestation, and their body condition at mating was better than those hinds that had gestated. Also, calves from hinds that had reproductive rest the preceding year were heavier at birth than the others. Nevertheless, the probability of bearing a male was greater with increasing age, but not with reproductive rest or any other variable. Total milk yield was positively affected by hind postcalving weight and hind age at mating, but not by reproductive rest.In conclusion, reproductive effort during the preceding breeding influenced the subsequent gestation, having an effect on the following variables: hind weight and body condition at mating, hind weight gain during gestation, postcalving weight, and calf birth weight.     

Age-related body weight constraints on prenatal and milk provisioning in Iberian red deer (Cervus elaphus hispanicus) affect allocation of maternal resources

Maternal phenotypic characteristics can influence key life history variables of their offspring through maternal effects. In this study, we examined how body size constraints on maternal weight in yearling and subadult compared to adult hinds (age class effects) affected prenatal (calf birth weight, calf to hind weight ratio) and postnatal (milk) provisioning of Iberian red deer calves. Age correlated with all prenatal and postnatal investment traits except calf gains, although correlations were weaker than those with maternal weight. Once the effect of linear increase in weight with age was removed from models, yearlings showed additional reductions in calf birth weight, calf gains, and milk provisioning. The low-calf birth weight might increase the risk of calf mortality during lactation, as this occurs primarily during the first day of life and is strongly related to birth weight. Yearlings showed a greater prenatal allocation of resources in terms of greater calf to hind weight ratio probably as an extra effort by yearling mothers to balance calf neonatal mortality. It might compensate young mothers to produce low-quality calves while still growing rather than waiting for the uncertain possibility of surviving to the next reproductive season.     

Antler mineral composition of Iberian red deer <Emphasis Type="Italic">Cervus elaphus hispanicus</Emphasis> is related to mineral profile of diet

Previous studies have suggested that antlers are costly bone structures whose mineral composition may change depending on physiological and other factors. This study examined whether nutrition variation associated with deer management influences antler mineral composition and structural characteristics of whole antler. Mineral distribution and bone structure were examined in antlers from two groups of adult Iberian red deer Cervus elaphus hispanicus Hilzheimer, 1909. They were kept under different feeding regimes at an experimental deer farm and a game estate in southeastern Spain. Protein and mineral contents differed between the diet of captive deer and that of deer in the wild. Significant differences were found for Na, Mg, K and protein. Antler composition seems to reflect the diet, as antlers of deer differed in protein, Na, Mg and K, but not in total mineral content, Ca, Fe or Zn. Thus, management conditions related to nutrition are reflected on antler composition.     

Growth of the first antler in Iberian red deer (<Emphasis Type="Italic">Cervus elaphus hispanicus</Emphasis>)

In this study, we describe the process of pedicle and first antler growth in Iberian red deer (Cervus elaphus hispanicus) and document relationships among body development, maternal milk supply and composition, and maternal weight on the length of first antlers. Antler length of 53 males of Iberian red deer was measured every 2 weeks from birth to 20 months of age. Deer weight, age, and the date of occurrence of the major events during the antler growth cycle were also recorded. The first evidence of pedicle development occurred when the animals were 38.0 ± 0.6 weeks old and weighed 60.7 ± 0.9 kg. Antler cleaning took place at a mean age of 63.8 ± 0.7 weeks and a mean weight of 91.5 ± 1.8 kg. The antler growth period lasted 16.7 ± 0.4 weeks, and the cleaning period lasted 5.1 ± 0.4 weeks. First antler growth followed a sigmoid curve, reaching a final length of 38.3 ± 1.0 cm. Antler length was positively correlated with body weight during the antler growth cycle. Additionally, the final length of the first antler was related to total milk yield, date of antler growth initiation, body weight at 6 months of age, and the antler growth time interval.     

Compensatory extension of gestation length with advance of conception in red deer (Cervus elaphus)

Calving date in many mammals is matched to the time of greatest food availability. Out of season calving results in heavy penalties in terms of own and offspring survival or body condition. This study examined whether gestation length is affected by advancing fertilisation. Thirty-six red deer hinds (of the Iberian and Scottish subspecies) were subjected to a synchronisation treatment of oestrus, ovulation, and artificial insemination on three dates, with remaining non-pregnant females mated with an intact male in a last group. Gestation was longer the more the fertilisation was advanced; gestation lasted 241.5+/-1.3 days (d) in the first group, 237.4+/-1.2 d in the second, 235.1+/-1.3 d in the third, and 231.2+/-1.6 d in the last. Mean gestation lasted 234.2+/-0.7 d. Hinds gained less weight during gestation the more the fertilisation was advanced. The difference was due at least in part to net body weight of the hind after calving compared to that at mating, and calves did not differ in birth weight. As early born calves suffer greater mortality in the field, this enlargening of gestation might be a compensatory response of the hinds to match calving with food availability. Under natural conditions, similar small modifications of gestation length may help hinds to overcome short-term adverse conditions for calving. Because calf mortality is correlated with birth weight, hinds may have kept calf birth weight constant at the expense of greater body weight loss.     

The effect of conception date on gestation length of red deer (Cervus elaphus)

Recent studies have demonstrated that gestation length of red deer (Cervus elaphus) is highly variable and influenced by various environmental factors, and this may confer survival advantages for neonates. The current study investigated the relationship between conception date and gestation length to test the hypothesis that within-herd synchrony of red deer births is facilitated by a 'push/pull' control over gestation length, such that hinds conceiving early and late in the breeding season have longer and shorter gestation periods, respectively. In Study 1, data on conception and calving dates were obtained for 393 naturally cycling hinds across two herds. In Study 2, conception and calving dates were obtained from 91 hinds in which oestrus/conception were artificially synchronised across a 4-week range of dates spanning the natural rut. Gestation length for each population was analysed by linear regression, fitting conception day followed by terms for the fixed effect which included hind age (pubertal vs. adult), hind genotype (Cervus elaphus scoticus vs. Cervus elaphus hippelaphus and their crossbreds), calf sex, sire genotype (Study 1 only), birth weight and year. In Study 1, both populations of naturally cycling hinds exhibited highly significant (P<0.001) negative slopes (-0.36, -0.49) for the regression of gestation length against conception date, with indications of a significant hind genotype effect favouring shorter overall gestation lengths for crossbred hinds. Other effects for hind age, calf sex, birth weight, sire genotype and year were not significant. In Study 2, in which conception dates were artificially induced, there was a highly significant negative slope (-0.19), with a notable but non-significant effect of hind age favouring shorter overall gestation length for primiparous (pubertal) hinds (P>0.05). Other effects for hind live weight, calf sex and calf birth weight were not significant. All data sets support the hypothesis, and indicate that for every 10 days difference in conception date there was a change in gestation length of 1.9-4.9 days. This hints at the adaptive importance of optimisation of birth date in wild populations of red deer but the precise physiological mechanisms remain to be resolved. It is postulated that variation in fetal age during the latter stages of pregnancy, when feed quality and voluntary feed intake cycles are in a state of flux, may drive differential growth trajectories for early and late conceived fetuses, leading to nutritional control over fetal maturation and induction of parturition. However, consideration is also given to a putative direct effect of prevailing photoperiod on control of parturition processes in red deer.     

Milk intake and production curves and allosuckling in captive Iberian red deer, Cervus elaphus hispanicus

In two experiments, we compared milk intake (assessed by weighing calves before and after suckling) and milk production (by hand milking hinds) in Iberian red deer both when calves sucked their mothers together (group-suckling experiment) and when mother and offspring were isolated (isolation-suckling experiment). In both experiments, the general lactation curve for calves increased to a peak and then decreased (type I, standard lactation curve in mammals), whereas the curve for hinds decreased from the start (type II). However, in the experiment on group suckling, calves ingested 17.2% more milk than that produced by their mothers from weeks 6 to 20. In both isolation- and group-suckling experiments, hinds showed an overproduction of milk decreasing from weeks 1 to 5. This decreasing overproduction coincides with a similar trend in calf mortality reported in the literature and might thus be aimed at ensuring calves have sufficient nutrients when mortality is highest. In addition, allosuckling observations in the group-suckling experiment showed an inverse relationship between milk production and percentage of allosucking attempts. Allosucking attempts were also more frequent after the milk overproduction period. Both findings suggest that allosuckling is a response to compensate for a reduced maternal milk supply. Copyright 2000 The Association for the Study of Animal Behaviour.     

Prostaglandin (PGF2 alpha)-induced parturition in red deer (Cervus elaphus L.)

Prostaglandin PGF2 alpha seems to act satisfactorily as a birth inducing agent in red deer (Cervus elaphus). The progress of actual delivery and lactation in the experiments of induced parturition corresponds with observations from natural conditions. The pattern of response time to the birth inducing agent agrees with experience from domesticated species, being longest in females with the least developed fetuses. Complications such as those reported from practice with induced parturition in domestic species were not experienced in the three experiments on red deer. Applications of prostaglandin PGF2 alpha prior to approximately 18-20 days preterm probably reduce chances for the offspring to survive. This seemingly being due to ontogenetical immaturity in the fetus, and deficient hormonal development in the mother, necessary for normal lactogenesis.     

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.     

A genetic study of sika (Cervus nippon) in the New Forest and in the Purbeck region, southern England: is there evidence of recent or past hybridization with red deer (Cervus elaphus)?

Sika Cervus nippon are native to Japan and East Asia but are now naturalized in many parks of the world, including Britain. In contrast to the substantial body of research on the extent of hybridization between sika and red deer Cervus elaphus in Scottish populations, there has been little genetic analysis of the English populations of sika. Sika in England still have a patchy and discontinuous distribution; populations are thus still genetically isolated and may be expected to show higher variability in genetic type. The current paper uses DNA-based techniques to explore the genetic composition of sika in the New Forest (Hampshire) and that of sika from the largest population in England, in the Purbeck region (Dorset). The study aims were to determine whether New Forest sika show signs of recent interbreeding with New Forest red deer populations, whether New Forest sika are genetically distinct from Purbeck sika, and whether New Forest and Purbeck sika show evidence of past hybridization or whether they are pure (non-hybrid) strains. Microsatellite analysis was used to compare the genetic profiles of individual deer. Results showed that sika and red deer in the New Forest were genetically distinct, indicating that there is no large-scale in situ hybridization occurring between these feral populations. In terms of overall genetic composition, there was no significant difference between the sika in the New Forest and Purbeck. However, a more detailed analysis found that New Forest sika showed a lower level of introgression with red deer compared with the Purbeck sika. We conclude that, overall, the New Forest sika deer do appear to be more genetically pure bred than the Purbeck sika.     

Changes in the yield, and carbohydrate, lipid and protein content of milk during lactation in the rat

The milk yield and composition was studied during the first three lactations of a group of rats. Milk yield increased steadily throughout the three lactations, but was somewhat lower during the first than subsequent lactations. Protein concentration was similar during all three lactations and varied little with stage of lactation. In contrast the lactose concentration, which was reasonably constant for the first 8 days post partum, increased thereafter two-fold by the end of the period studied in all three lactations. However, the N-acetyl-neuraminyl lactose concentration showed somewhat reciprocal changes. Considerable variations in the triacylglycerol concentration was found during the first lactation but few changes were observed during subsequent lactations. The free fatty acid concentration was at all times low and showed no significant changes during or between lactations. At most stages of lactation in raw milk, the major fatty acids are palmitate, oleate and linoleate. However, as lactation progresses there is an increase in the proportion of medium-chain saturated fatty acids and a corresponding decrease in the proportion of long chain unsaturated fatty acids in milk fat. Clearly the composition of milk is not invariable but changes both during and between lactations. Such changes may be expected to have some influence on the metabolism of the offspring.     

Some properties of Red deer (Cervus elaphus) at exceptionally high population-density in Scotland

This paper records some features of Red deer ( Cervus elaphus L.) at very high population density on a Scottish island. About half the total population was shot-out in autumn 1974, and half the remainder in autumn 1975, with special searches for deer which had died of natural causes during the intervening year. In all, the animals examined amounted to 80% of the original population, and from the data gathered it was possible to (i) assess the structure and reproductive features of the original population; (ii) examine the level of animal performance at this exceptionally high population-density; and (iii) check for any changes in performance arising from the initial reduction in density.
The sex-ratio of adults in the original population showed a small excess of hinds, stags being apparently subject to a higher mortality rate than hinds after about six years of age. In performance, these deer were much the same as those living elsewhere on Scottish hill-land at relatively high population-density, i.e. with delayed puberty and poor breeding rates in hinds, and with much smaller adults than in woodland habitats. But, contrary to expectation, the general level of performance was not unusually low for Red deer on Scottish hill-land, and there was no evidence of transmissible diseases or excessive parasitism. It was also surprising that the animals showed no improvements in performance following their first reduction; if anything, they were slightly poorer after one year at reduced density. This may have been a temporary consequence of the severe disruption of existing behaviour patterns brought about by the sudden loss of many groups of deer.     

Transfer of bovine microsatellites to the cervine (Cervus elaphus)

Bovine microsatellites were used to amplify DNA of red deer ( Cervus elaphus ). Fourteen of 27 bovine systems (52%) displayed polymorphism, while no (CA)_n-repeat was detected in seven systems and six systems gave no amplificates in red deer. The allele number ranged from 2 to 7, the polymorphism information content between 0.24 and 0.76. The results demonstrate that transfer of microsatellite systems between families of the same order (artiodactyla) is possible. Molecular genetic research will help to clarify the differentiation and ecology of wild animals and will contribute to define criteria needed for the preservation of endangered species.     

Testing for genetic trade-offs between early- and late-life reproduction in a wild red deer population

The antagonistic pleiotropy (AP) theory of ageing predicts genetically based trade-offs between investment in reproduction in early life and survival and performance in later life. Laboratory-based research has shown that such genetic trade-offs exist, but little is currently known about their prevalence in natural populations. We used random regression 'animal model' techniques to test the genetic basis of trade-offs between early-life fecundity (ELF) and maternal performance in late life in a wild population of red deer (Cervus elaphus) on the Isle of Rum, Scotland. Significant genetic variation for both ageing rates in a key maternal performance measure (offspring birth weight) and ELF was present in this population. We found some evidence for a negative genetic covariance between the rate of ageing in offspring birth weight and ELF, and also for a negative environmental covariance. Our results suggest rare support for the AP theory of ageing from a wild population.     

Seasonal coat changes in grazing Red deer (Cervus elaphus)

Seasonal change in the coat of four male and four female Red deer (Cervus elaphus) was studied in coat and skin samples taken monthly for two years. Changes in coat length were measured, the times of moult recorded, and the cycle of follicle activity determined from histological preparations.     

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.