Effect of age on nutritional properties of Iberian wild red deer meat.

BACKGROUND: This study assessed the effect of age (L, less than 27 months old; M, from 27 to 42 months old; H, 43 months and older) on the fatty acid profile, cholesterol content, amino acid composition and mineral content of 150 Iberian wild red deer meat samples. RESULTS: Intramuscular fat content increased (P < 0.05) with age (0.05 vs 0.12 vs 0.34% for L, M and H groups respectively), while cholesterol content decreased (P < 0.05) as the slaughter age increased (52.78 vs 48.72 vs 45.34 mg per 100 g meat for L, M and H groups respectively). The slaughter age showed differences among groups for saturated fatty acids, with the highest content in older animals (30.41 vs 34.55 vs 38.21% for L, M and H groups respectively), whereas younger deer displayed the highest polyunsaturated fatty acid levels (50.05 vs 45.24 vs 37.55% for L, M and H groups respectively). The n-6/n-3 ratio was more favorable (P < 0.05) for young and medium ages compared with that for older animals. In contrast, amino acid profile and mineral content were only slightly affected by age. CONCLUSION: As a general conclusion, wild red deer meat could be considered a good alternative to red meats for human consumption. © 2018 Society of Chemical Industry.

Carcass and meat quality characteristics from Iberian wild red deer (Cervus elaphus) hunted at different ages.

BACKGROUND: Deer-meat consumption is increasing in several countries based on claims that it is a healthy red meat. This study assessed the effect of slaughter age (low - 26 months and younger; medium - from 27 months to younger than 42 months; and high - 42 months and older) on carcass characteristics and meat physicochemical properties of 150 Iberian wild red deer. RESULTS: Whole carcass yields of neck, backbone and flank increased (P < 0.001) with age, while yields of shoulder, tenderloin and leg decreased (P < 0.05) with age. The pH measured at 48 h post mortem at 9th rib level was not affected by age, while pH measured at 72 h post mortem at the longissimus thoracis et lumborum muscle decreased (P < 0.05) with age. Meat chemical composition was not affected by slaughter age, except for intramuscular fat (IMF), which increased (P < 0.05) with slaughter age. Finally, cooking loss and shear force were higher (P < 0.05) in meat from older deer. CONCLUSION: Most characteristics of meat from wild red deer depend on age at slaughter. The greater IMF of meat from older animals may render it more palatable. However, meat shear force also increased with age. Additional studies testing palatability seem to be necessary to evaluate the effects of slaughter age on the sensorial quality of meat from Iberian wild red deer. © 2018 Society of Chemical Industry.

The bony horncore of the common eland (Taurotragus oryx): composition and mechanical properties of a spiral fighting structure.

Horns are permanent structures projecting from the head of bovids, consisting of a bony horncore covered with a layer of skin and then a sheath of keratinous material showing variability of growth intensity based on nutrition. From the point of view of the horn's mechanical properties, the keratin sheath has been widely studied, but only a few studies have considered the complete structure of the horn and fewer studies have focused on the bony horncore and its characteristics. The latter showed the important role of the bony core, when cranial appendages are subject to mechanical stress (as happens during fighting). The mechanical properties of bone material, along with its mineral profile, are also important, because they can show effects of different factors, such as nutrition and mineral deficiencies in diet. For this reason, eight horncores of captive common eland male were sampled at four positions along the vertical axis of the horn. The main aim was to study variation in mechanical properties and the mineral content along the vertical axis of the horncores. We further analysed whether the spiral bony ridge present on eland horncores differs in any of the studied properties from adjacent parts of the horncore. In other antelopes, spiral ridges on the horns have been proposed to increase grip during wrestling between males. Cross-sections of the horncores were performed at four positions along the longitudinal axis and, for each position, two bone bars were extracted to be tested in impact and bending. Moreover, in the first sampling position (the closest position to the base) two bars were extracted from the spiralled bony area. The resulting fragments were used to measure ash content, bone density and mineral content. Results showed that horn bone decreased along the vertical axis, in ash (-36%), density (-32%), and in impact work 'U' (marginally significant but large effect: -48%). The concentration of several minerals decreased significantly (Mg, Cr, Mn and Tl by -33%, -25%, -31%, -43%, respectively) between the basal and the uppermost sampling site. The bone tissue of the horncore spiral compared with non-spiral bone of the same position showed a lower ash content (53% vs. 57%), Mg and Mn; in addition to showing approximately half values in work to peak force 'W', bending strength 'BS' and 'U', but not in Young's modulus of elasticity 'E'. In conclusion, similarly to the results in a totally different fighting bony structure, the antlers, the horncore of eland shows advantageous parameters in bone tissue of the base in respect to the tip, with higher values for mechanical properties, density and mineral profile. Moreover, the spiral bone tissue showed lower material mechanical properties. Probably the spiral tissue of the horn may have a role in deflecting potential cross-sectional fractures during wrestling. In addition, it may serve to improve the grip during wrestling, and we propose that it may also prevent risk of rotation of sheath with respect to internal bone not only in this, but also in other straight bovid horns.

The Many Axes of Deer Lactation.

In undomesticated animals information about the production and composition of milk over time is still scarce. In general, for most mammals it is known that milk composition changes across lactation, is different for male and female offspring, and even that marsupials, such as kangaroos, can simultaneously produce milk of different compositions for young of different ages. Such parallel milk production of differing compositions has not yet been studied in single-offspring placental mammals, but may help to explain behavioural processes like allosuckling (feeding the young of other adults) and lateralized suckling preferences. In this study we analysed the production and composition of milk in red deer throughout the lactation period and now confirm for the first time that there are axial differences present. The front teats, which are the favoured suckling positions of the deer's offspring, produce milk with a greater protein-to-fat ratio. Also, from the beginning of lactation the yield is greater on the left side, the side preferred by calves in all of the studied species, both at population and individual level. The links between milk production and calf behaviour in deer deserve further study.

The power of oral and nasal calls to discriminate individual mothers and offspring in red deer, Cervus elaphus.

BACKGROUND: In most species, acoustical cues are crucial for mother-offspring recognition. Studies of a few species of ungulates showed that potential for individual recognition may differ between nasal and oral contact calls. RESULTS: Vocalizations of 28 hinds and 31 calves of farmed Iberian red deer (Cervus elaphus hispanicus) were examined with discriminant function analyses (DFA) to determine whether acoustic structure of their oral and nasal contact calls encodes information about the caller's identity. Contact calls were elicited by brief separation of individually identified animals by a distance over 10 m or by a bar fence. Both oral and nasal calls of both hinds and calves showed high potential to discriminate individuals. In hinds, individuality was significantly higher in the oral than in the nasal calls, whereas in calves, individuality was equally well expressed in both oral and nasal calls. For calves, the maximum fundamental frequency was higher and the duration was longer in oral calls than in nasal calls. For hinds, the maximum fundamental frequency and the duration were indistinguishable between oral and nasal calls. Compared to the pooled sample of oral and nasal calls, separate oral or nasal call samples provided better classifying accuracy to individual in either hinds or calves. Nevertheless, in both hinds and calves, even in the pooled sample of oral and nasal calls, the degree of individual identity was 2-3 times greater than expected by chance. For hinds that provided calls in both years, cross-validation of calls collected in 2012 with discriminant functions created with calls from 2011 showed a strong decrease of classifying accuracy to individual. CONCLUSIONS: These results suggest different potentials of nasal and oral calls to allow the discrimination of individuals among hinds, but not among red deer calves. The high potential of individual recognition even with the pooled sample of oral and nasal calls allows mother and young to remember only one set of acoustic variables for mutual vocal recognition. Poor between-year stability of individual characteristics of hind oral and nasal calls would require updating keys to individual recognition each calving season.

Can Iberian red deer (Cervus elaphus hispanicus) discriminate among essential minerals in their diet?

Optimal foraging predicts that animals should be able to assess the content of important nutrients in food. Ungulates discriminate salt and P, but discrimination of other minerals is controversial even though they are also essential and often limiting. Animal scientists have explained this taste through palatability, which predicts the same pattern of discrimination for calves and hinds and greater consumption by the latter. Social learning may also be involved, predicting a correlation between mother and calf and less consumption by the latter. The present study examines the consumption behaviour of free-choice supplemented minerals by hinds and calves of Iberian red deer (Cervus elaphus hispanicus) to discern between these hypotheses. Behavioural indices of intake correlated with actual mineral consumption (P < 0.001). Mother and calf behavioural indices correlated only for salt-mixed minerals. Calves showed overall behavioural indices of consumption greater than hinds (P < 0.01 and P < 0.001), and also for all single supplements except NaCl, as expected from growth needs and in contrast to the palatability hypothesis. Calves showed a greater consumption of CuSO(4) and lower of Na(2)SeO(3) than pure salt. Hinds showed a different pattern, ingesting lower amounts of all minerals except CuSO(4) and salt. Additional analyses also showed discrimination between minerals unmixed with salt, such as CaHPO(4) and CaCO(3) (P = 0.012 and P = 0.020). The greater intake of growing calves and the different consumption patterns for hinds and calves suggest that deer can discriminate among minerals, and that they do not consume minerals for their palatability or driven by social learning. Therefore, deer may be selecting minerals according to nutritional requirements.

Direct versus indirect effects of social rank, maternal weight, body condition and age on milk production in Iberian red deer ( Cervus elaphus hispanicus).

Social rank in cervids and other mammals is not entirely predicted by body weight, but in most cases influences access to food directly. Milk provisioning depends on maternal weight and on daily food intake. Usually, body weight, body condition, age and social rank are inter-correlated making it very difficult to discern the relative importance of each variable to milk production. This study used path analysis to assess direct versus indirect effects of these variables on milk production of 62 Iberian red deer hinds (Cervus elaphus hispanicus). Once the known direct effects of body weight and body condition were set as fixed, hind age and social rank did not affect milk production directly. In contrast, they exerted an indirect influence through the correlation both with hind body weight and body condition. Body weight exerted an effect on milk production nearly twice as great as that of body condition. This study shows, for the first time in a wild mammal, the relative importance of social rank, body weight, body condition and age in affecting milk production ability.

Roe deer as a bioindicator: preliminary data on the impact of the geothermal power plants on the mineral profile in internal and bone tissues in Tuscany (Italy).

The European roe deer (Capreolus capreolus) is one of the most abundant ungulate species in Europe. Many studies have investigated its distribution, behavior, and ecology, but few have focused on its role as bioindicators for pollutants, particularly regarding antlers, which has been shown to indicate also deer physiology. The presence of geothermal power plants can induce accumulation of potentially polluting elements (such as Tl, S, and Pb). Thus, we collected roe deer samples from areas of Tuscany (Italy) where power plants are present. They were divided according to whether their home range included areas close or far from geothermal power plants. We analyzed the body measurements and the profile of the minerals in the liver and antlers tissues using the ICP-OES technique. Results showed that livers from roe deer close to power plant accumulated higher quantity of Bi, Co, Ni, Tl, and S compared to controls. Males culled close to geothermal power plants had significantly lower values for weight and chest circumference, and also, the antlers showed higher values for Li and Sr in the first sampling position. Thus, despite the small sample size in this preliminary study, antlers and livers of roe deer seem to be a bioindicator of industrial impact on the environment.

Parenteral Cu Supplementation of Late-Gestating and Lactating Iberian Red Deer Hinds Fed a Balanced Diet Reduces Somatic Cell Count and Modifies Mineral Profile of Milk.

: This study describes the effects that Cu supplementation of late-gestating and lactating females (hinds) of Iberian red deer fed a balanced diet have on milk production, composition, and somatic cell count (SCC). Experimental hinds (n = 9) were subcutaneously injected every 42 days with Cu (0.83 mg Cu/kg body weight) from day 202 of gestation until the end of lactation (week 18). Control hinds (n = 8) were injected with a physiological saline solution with the same volume and at the same frequency as the experimental group. Copper supplementation decreased the SCC from 1.64 to 1.36 log 10/mL (p = 0.003) and modified the milk mineral profile. In particular, milk from hinds supplemented with Cu had more Ca (p = 0.02), Mg (p = 0.06), and K (p = 0.03) than milk from control hinds. However, Cu supplementation did not influence the Cu content of milk. Therefore, it can be concluded that Cu supplementation of hinds fed a balanced diet from late-gestation to the end of lactation could be a good strategy to reduce SCC and modify the mineral profile of milk increasing its Ca content.

Quality of main types of hunted red deer meat obtained in Spain compared to farmed venison from New Zealand.

Deer venison is increasingly valued as a natural meat. This study examines the three main sources of venison: farmed venison from New Zealand (NZ), the world's leading producer, and wild deer from Spain (SP), the second largest producer, which mainly supplies venison from traditional autumn-winter driven hunts (monteria), involving packs of dogs, and a smaller proportion culled through summer selective stalking. Meat from NZ contained more protein, lower shear force and lower n-6/n-3 ratio (P < 0.01). Spanish meat had a greater content of total, essential and non-essential amino acids (P < 0.01). Meat from deer culled in winter had lower intramuscular fat and saturated fatty acids (FA) but higher polyunsaturated FA (P < 0.01) and pH (P < 0.001) than meat from summer stalked deer. Therefore, venison presents differences by country of origin for composition, FA and texture that are likely to affect its health characteristics. Anomalies observed in meat between the winter driven hunt and non-stressful summer stalking may be attributed to the level of death stress in the case of variables such as pH. However, the effect on fat and mineral composition seems to be seasonal, depending respectively on wild diet or cyclic osteoporosis in males.

Different maternal investment strategies for male and female calves in a polygynous mammal.

Maternal effects occur when the phenotype of the mother influences that of the young to the detriment of her survival, growth or fitness. The investment of the mother can be affected by maternal body condition and/or experience. Trivers-Willard Hypothesis (TWH) and Local Resource Competition Hypothesis (LRCH) are the main hypotheses used to explain bias in birth sex-ratios in mammals, as well as for sex-biased maternal investment. Both hypotheses suggest that a different amount of investment must be expected according to the sex of the young. However, recent studies suggest that these differences are not in quantity but in the strategies: mechanisms and objectives may differ for each sex. We studied how maternal characteristics (age, body mass, body condition, and dominance status) influence relevant aspects of the birth and early growth of the calf (birth date, birth body mass, body mass at weaning, and body condition at weaning) separately for each sex; and how that investment is mediated by milk production and composition (lactose, fat, and protein). One hundred eighty-eight newborns from 75 captive red deer hinds aged from 2 to 19 years were analyzed. The main differential investment observed was related to birth date: when producing a female, hinds give birth earlier in the season only if they have a good body condition; however, when gestating a male it is the older hinds those which deliver earlier. Subsequently, milk production and composition are correlated with birth body mass in female calves, but to weaning body mass in males. Thus, only hind body mass affects the weaning body mass of female calves, compared with age and hind body mass in males. These results suggest that while TWH fits the maternal investment strategy found for male calves, it is LRCH which correlates with the maternal investment patterns observed for females.

Social rank affects the haematologic profile in red deer hinds.

We studied the effects of social rank on the haematologic profile in a herd of 24 female Iberian red deer hinds. Social rank hierarchy was determined and blood samples were taken and analysed. After adjusting for age and body mass, dominance ranking showed a significant negative effect (ie, lower values in dominant hinds) on white blood cell (WBC) count, haemoglobin and haematocrit. Our results are similar to those reported for stressed individuals due to physical immobilisation, but do not support the predicted enhanced erythropoiesis due to higher levels of androgens. The results for WBC numbers may also reflect that subordinate hinds must allocate a higher amount of resources to immunity as a result of injuries incurred from dominant hinds, while simultaneously facing restricted access to food sources. For red blood cell (RBC) counts, the results may be due to subordinate hinds likely needing increased haematocrit and haemoglobin levels for fast flight responses. Our data show that social rank influences haematologic profile, and thus it should be considered when correctly interpreting blood analyses in social cervid species.

Between-year vocal aging in female red deer (Cervus elaphus).

OBJECTIVES: Studying animal vocal aging has potential implication in the field of animal welfare and for modeling human voice aging. The objective was to examine, using a repeated measures approach, the between-year changes of weight, social discomfort score (bites of other hinds on hind pelt), body condition score (fat reserves) and acoustic variables of the nasal (closed-mouth) and the oral (open-mouth) contact calls produced by farmed red deer hinds (Cervus elaphus) toward their young. RESULTS: Repeated measures ANOVA revealed that with an increase of hind age for 1 year, the acoustic variables of their nasal contact calls (the beginning and maximum fundamental frequencies, the depth of frequency modulation and the peak frequency) decreased, whereas in their oral contact calls only the end fundamental frequency decreased. Duration and power quartiles did not change in any call type. Body weight and body condition score increased between years, whereas discomfort score decreased. Results of this study revealed directly the short-term effects of aging on the acoustics of the nasal contact calls in the same hinds. This study also confirmed that elevated emotional arousal during emission of the oral contact masks the effects of aging on vocalization in female red deer.

Effect of advancing births on testosterone until 2.5 years of age and puberty in Iberian red deer (Cervus elaphus hispanicus).

This study aimed to determine the age of attainment of puberty, as well as the pattern of reproductive seasonality in males of Iberian red deer and the relationship of these factors with antler development. A second aim was to examine the effect of the advance of births on the variables mentioned. Fourteen males of Iberian deer were used, five of them born 2.5 months before the others (early group). Male deer were blood sampled from birth until 2.5 years of age to assess the time course of plasma testosterone. The study also included measurements of testicular and neck circumference. As in most cervids, concentration of plasma testosterone was associated to the phases of antler development. Early development affected testosterone titres, since the most precocious males in antler growth also showed higher levels of testosterone during the first and second year of age. In the same way, results suggested that the advance of calving may result in puberty attainment in the first autumn of its life. However, this would require an advance of calving greater than the one we induced since puberty in the Iberian deer is usually attained during second autumn of life at 15-16 months of age. Finally, calving advance also affected antler development. Thus, two of the five males whose birth was advanced, showed two antler cycles in their first year of life.

Avoiding toxic levels of essential minerals: a forgotten factor in deer diet preferences.

Ungulates select diets with high energy, protein, and sodium contents. However, it is scarcely known the influence of essential minerals other than Na in diet preferences. Moreover, almost no information is available about the possible influence of toxic levels of essential minerals on avoidance of certain plant species. The aim of this research was to test the relative importance of mineral content of plants in diet selection by red deer (Cervus elaphus) in an annual basis. We determined mineral, protein and ash content in 35 common Mediterranean plant species (the most common ones in the study area). These plant species were previously classified as preferred and non-preferred. We found that deer preferred plants with low contents of Ca, Mg, K, P, S, Cu, Sr and Zn. The model obtained was greatly accurate identifying the preferred plant species (91.3% of correct assignments). After a detailed analysis of these minerals (considering deficiencies and toxicity levels both in preferred and non-preferred plants) we suggest that the avoidance of excessive sulphur in diet (i.e., selection for plants with low sulphur content) seems to override the maximization for other nutrients. Low sulphur content seems to be a forgotten factor with certain relevance for explaining diet selection in deer. Recent studies in livestock support this conclusion, which is highlighted here for the first time in diet selection by a wild large herbivore. Our results suggest that future studies should also take into account the toxicity levels of minerals as potential drivers of preferences.

Manganese Supplementation in Deer under Balanced Diet Increases Impact Energy and Contents in Minerals of Antler Bone Tissue.

Bone ash, collagen, Ca and P composition, are considered the main factors affecting mechanical properties in bones. However, a series of studies in bone and antler have shown that some trace minerals, such as manganese, may play a role whose importance exceeds what may be expected considering their low content. A previous study showed that a reduction in manganese in antlers during a year of late winter frosts led to generalized antler breakage in Spain, which included a reduction of 30% of cortical thickness, 27% reduction in impact energy, and 10% reduction in work to peak force. Starting for this observation, we experimentally studied the effects of manganese supplementation in adults and yearling (yearlings) red deer under a balanced diet. Subjects were 29 deer of different age classes (adult n = 19, yearlings n = 10) that were divided in a manganese injected group (n = 14) and a control group (n = 15). Antler content in ashes and minerals, intrinsic mechanical properties and cross section structure were examined at 4 points along the antler beam. A one way ANOVA (mean per antler) showed that in yearlings, manganese supplementation only increased its content and that of Fe. However, in adults, Mn supplementation increased the mean content per antler of Ca, Na, P, B, Co, Cu, K, Mn, Ni, Se (while Si content was reduced), and impact work but not Young's modulus of elasticity, bending strength or work to peak force. A GLM series on characteristics in the uppermost part examined in the antler, often showing physiological exhaustion and depletion of body stores, showed also a 16% increase in work to peak force in the antlers of the treated group. Thus, manganese supplementation altered mineral composition of antler and improved structure and some mechanical properties despite animals having a balanced diet.

Subspecies and body size allometry affect milk production and composition, and calf growth in red deer: comparison of Cervus elaphus hispanicus and Cervus elaphus scoticus.

Studies comparing lactation in wild mammals have shown that maternal weight scales with offspring weight, milk production, or its energy. However, no study appears to have scaled milk composition with maternal or offspring weight. Although diet affects milk composition and production, their effects in biological studies have almost never seemed to be controlled. In this study, we compare two subspecies of red deer, Scottish deer, Cervus elaphus scoticus (10 lactations), and Iberian deer, Cervus elaphus hispanicus (14 lactations), kept under the same diet and housing to assess differences in hind and calf weights and their trends, milk production and composition, and their allometric relationships. Scottish hinds were heavier, and calf weight and gains were greater than Iberian ones, with greater milk production and milk protein content, but they did not differ in fat or lactose content. Calf birth weight, milk production, and protein content showed significant allometric relationships with maternal weight, but no relationship was found for fat, lactose, or any of these variables with calf birth weight. Protein content correlated with calf birth weight, and calf weight trend depended on milk protein production rather than on that of fat or lactose. Protein may be the most important milk component to explain growth and milk composition differences between closely related mammals.

Why do cervids feed on aquatic vegetation?

Consumption of aquatic plants is rare among cervids, despite the common occurrence of this form of vegetation. However, the paucity of literature reporting on this feeding behaviour suggests that Na (but also other minerals), protein, and the ubiquitous availability of aquatic vegetation may play a role in its consumption. We present results quantifying those factors that regulate the consumption of aquatic plants in the Iberian red deer. We focussed our study primarily on two questions: (i) what nutritional values are red deer seeking in the aquatic plants?; and (ii) why do red deer primarily use aquatic plants during the summer? A comparison of the seasonal variations in Na content between terrestrial vs. aquatic vegetation did not fully support the hypothesis that aquatic plants are being consumed more in summer because of any seasonal variation in Na availability. The Na content in the aquatic vegetation was adequate all the year-round; whereas, the Na content in the terrestrial vegetation was consistently deficient. However, a greater summer content of essential minerals and protein in the aquatic vegetation may be the cause for their consumption exclusively during the summer. We suggest that seasonal variations in the consumption of aquatic vegetation by cervids is primarily driven by temporal variations in the nutrient content, combined with seasonal variations in the physiological demands for these nutrients.

Effects of feed supplementation on mineral composition, mechanical properties and structure in femurs of Iberian red deer hinds (Cervus elaphus hispanicus).

Few studies in wild animals have assessed changes in mineral profile in long bones and their implications for mechanical properties. We examined the effect of two diets differing in mineral content on the composition and mechanical properties of femora from two groups each with 13 free-ranging red deer hinds. Contents of Ca, P, Mg, K, Na, S, Cu, Fe, Mn, Se, Zn, B and Sr, Young's modulus of elasticity (E), bending strength and work of fracture were assessed in the proximal part of the diaphysis (PD) and the mid-diaphysis (MD). Whole body measures were also recorded on the hinds. Compared to animals on control diets, those on supplemented diets increased live weight by 6.5 kg and their kidney fat index (KFI), but not carcass weight, body or organ size, femur size or cortical thickness. Supplemental feeding increased Mn content of bone by 23%, Cu by 9% and Zn by 6%. These differences showed a mean fourfold greater content of these minerals in supplemental diet, whereas femora did not reflect a 5.4 times greater content of major minerals (Na and P) in the diet. Lower content of B and Sr in supplemented diet also reduced femur B by 14% and Sr by 5%. There was a subtle effect of diet only on E and none on other mechanical properties. Thus, greater availability of microminerals but not major minerals in the diet is reflected in bone composition even before marked body effects, bone macro-structure or its mechanical properties are affected.

A review of factors affecting antler composition and mechanics.

Antlers constitute the only mammal model for limb regeneration. A number of factors affect antler regeneration. In this review, we examine such factors and the potential consequences for organ regeneration. As body mineral stores are depleted to grow antlers, physiological exhaustion is shown in the mineral composition, mechanical performance and, according to preliminary studies, porosity of the antler bone material. Nutrition plays an important role in antler characteristics. Thus, antler composition can be used as a diagnostic tool to assess mineral deficiencies in deer. Studies on ecological effects of exceptional weather in plants suggest that minor minerals, particularly Mn, may play disproportionately roles in mechanical performance of bone material. This suggests that Mn (and perhaps other minerals) is essential to incorporate Ca and P from resorbed skeleton material in antlers. Apart from implications for game management, some effects may have applications for medicine.