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Uwe Kierdorf - One of the best experts on this subject based on the ideXlab platform.
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multiple osteochondromas of the Antlers and cranium in a free ranging white tailed deer odocoileus virginianus
PLOS ONE, 2017Co-Authors: Uwe Kierdorf, Santiago Gomez, Karl V Miller, Stefan Flohr, Horst KierdorfAbstract:This paper reports a case of multiple osteochondromas affecting the Antlers and the left zygomatic bone of a free-ranging adult white-tailed buck (Odocoileus virginianus) from Georgia, USA. Along with a few postcranial bones, the Antlered cranium of the individual was found in a severely weathered condition and devoid of any soft tissue. The Antlers exhibited five pedunculated exostoses that were composed of cancellous bone and, in their peripheral portions, also mineralized cartilage. The largest of the exostoses, located on the right Antler, had a maximum circumference of 55 cm. The exostosis arising from the zygomatic bone was broad-based and much smaller than the exophytic outgrowths on the Antlers. Diagnosis of the exostoses as osteochondromas was based on their overall morphology, the normal bone structure in their stalk regions, and the continuity of their spongiosa and cortex with the respective components of the parent bones. Antleromas, i.e., pathological outgrowths developing on Antlers as a result of insufficient androgen production, were excluded in the differential diagnosis, based on (1) the apparent maturity and, except for the tumors, normal shape of the Antlers and (2) the fact that exostosis formation had also affected the zygomatic bone. Previously only a single case of solitary osteochondroma of an Antler has been described in the scientific literature. The case presented here is the first report of multiple osteochondromas in a deer. As Antlers are regularly collected as trophies, and huge numbers of them are critically inspected each year, the fact that thus far only two cases of Antler osteochondromas have been reported suggests that these tumors are very rare.
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element concentrations and element ratios in Antler and pedicle bone of yearling red deer cervus elaphus stags a quantitative x ray fluorescence study
Biological Trace Element Research, 2014Co-Authors: Uwe Kierdorf, Dieter Stoffels, Horst KierdorfAbstract:The present study compared the concentrations of different elements (Ca, P, Mg, Sr, Ba, K, S, Zn, Mn) as well as Ca/P, Ca/Mg, Sr/Ca, and Ba/Ca ratios in hard Antler and pedicle bone of yearling red deer stags (n = 11). Pedicles showed higher concentrations of calcium and phosphorus and a higher Ca/Mg ratio than Antlers, while Antlers exhibited higher concentrations of potassium, sulfur, and manganese as well as higher Ca/P, Sr/Ca, and Ba/Ca ratios. The findings indicate that Antlers are less mineralized and show less maturation of their bone mineral than pedicles. Antlers also showed a higher intrasample variation of mineralization than pedicles, which can be related to the shorter life span of the (deciduous) Antlers compared to the (permanent) pedicles. It is suggested that Antler bone formation is stopped before the theoretically possible degree of mineralization and mineral maturation is reached, resulting in Antler biomechanical properties (high bending strength and work to fracture) that are well suited for their role in intraspecific fighting. It is further suggested that the differences in Sr/Ca and Ba/Ca ratios of Antlers and pedicles are related to the dietary shift from milk to vegetation in combination with an increasing intestinal discrimination against Sr and Ba with age, resulting in a less marked difference in these ratios than would be expected based on the dietary shift alone. The findings of our study underscore the suitability of Antlers and pedicles as models of bone mineralization and the influence of different animal-related and/or external factors on this process.
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the structure of pedicle and hard Antler bone in the european roe deer capreolus capreolus a light microscope and backscattered electron imaging study
Journal of Anatomy, 2013Co-Authors: Uwe Kierdorf, Tomas Landetecastillejos, Santiago Gomez, Stefan Flohr, Horst KierdorfAbstract:Deer Antlers are deciduous bony structures that develop from permanent frontal outgrowths, the pedicles. While growth and bone architecture of Antlers have been studied in greater detail, information on pedicle formation and structure is scarce. The present study provides information on the structure of pedicle and hard Antler bone in the European roe deer. A pronounced seasonal variation in pedicle architecture was observed, with high porosity around Antler casting and a very compact bone structure during the hard Antler stage. These observations suggest a corresponding marked variation also in the biomechanical properties of the pedicles. The seasonally alternating extensive resorption and formation processes make the pedicles of older deer heavily remodeled structures. Pedicles increase in thickness by apposition of primary bone that subsequently becomes replaced by secondary osteons. The Antler cortex of roe deer is largely composed of a tubular framework of woven bone trabeculae with some remnants of mineralized cartilage, and primary osteons that have filled in the intertrabecular spaces. Secondary osteons are scarce, denoting little remodeling in Antlers, which can be related to their short lifespan. The occurrence of cement lines around primary osteons indicates resorption on the trabecular scaffold prior to infilling of the intertrabecular spaces. The outer cortex showed a higher autofluorescence and a more immature structure than the main cortex, suggesting that it was secondarily formed by periosteal activity. Pedicles and Antlers constitute a functional entity, and future histological and/or biomechanical studies should therefore consider both components of the cranial appendages.
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labeling studies on cortical bone formation in the Antlers of red deer cervus elaphus
Bone, 2013Co-Authors: Santiago Gomez, Andrés J. Garcia, Laureano Gallego, Uwe Kierdorf, Horst Kierdorf, Tomas Landetecastillejos, Salvador LunaAbstract:The formation and mineralization process of Antlers, which constitute the fastest growing bones in vertebrates, is still not fully understood. We used oxytetracycline injections to label different stages of bone formation in Antlers of 14 red deer between days 28 and 156 of Antler growth. Results show that initially a trabecular scaffold of woven bone is formed which largely replaces a pre-existing scaffold of mineralized cartilage. Lamellar bone is then deposited and from about day 70 onwards, primary osteons fill in the longitudinal tubes lined by the scaffold in a proximal to distal sequence. Mineral apposition rate (MAR) in early stages of primary osteon formation is very high (average 2.15 μm/d). Lower MARs were recorded for later stages of primary osteon formation (1.56 μm/d) and for the smaller secondary osteons (0.89 μm/d). Results suggest a peak in mineral demand around day 100 when the extent of mineralizing surfaces is maximal. A few secondary osteons were formed in a process of Antler modeling rather than remodeling, as it occurred simultaneously with formation of primary osteons. The degree of cortical porosity reflects a reduction in MAR during later stages of osteonal growth, whereas cortical thickness is determined earlier. Injections given when the Antlers were largely or completely clean from velvet produced no labels in Antler bone, strongly suggesting that Antlers are dead after velvet shedding. The rapidity of Antler mineralization and the short lifespan of Antlers make them an extraordinary model to assess the effects of chemicals impairing or promoting bone mineralization.
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deer Antlers a model of mammalian appendage regeneration an extensive review
Gerontology, 2011Co-Authors: Uwe Kierdorf, Horst KierdorfAbstract:Background: Compared with other vertebrate taxa, mammals possess a very limited capacity for appendage regeneration. The Antlers of deer are an exception in that they are periodically lost and fully regenerated throughout the life of an individual. Objective: In this paper we compare certain aspects of Antler regeneration with regenerative processes in other vertebrates. Methods: Review of the literature. Results: Recent studies suggest that Antler regeneration is a stem cell-based process and that these stem cells are located in the pedicle periosteum. There is evidence that signaling pathways known to operate during appendage regeneration in other vertebrates are also activated during Antler regeneration. There are, however, also differences between Antlers and other systems of epimorphic regeneration. Thus, contrary to amphibian limb regeneration, signaling from the wound epidermis appears not to be of crucial importance for Antler regeneration. Healing of the casting wound typically involves no or only minor scarring, making Antlers interesting subjects for researchers attempting to reduce scar formation during wound healing in humans. The fact that despite their enormous growth rate the Antlers of intact and castrated deer appear to be resistant to malignant transformation furthermore offers research opportunities for cancer biology. Conclusions: Studying Antler renewal as an example of mammalian appendage regeneration may provide crucial information for regenerative medicine to achieve its ultimate goal of stimulating limb regeneration in humans. A deeper understanding of the developmental mechanisms involved in Antler renewal can also be useful for controlling induced regeneration processes in mammals.
Horst Kierdorf - One of the best experts on this subject based on the ideXlab platform.
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multiple osteochondromas of the Antlers and cranium in a free ranging white tailed deer odocoileus virginianus
PLOS ONE, 2017Co-Authors: Uwe Kierdorf, Santiago Gomez, Karl V Miller, Stefan Flohr, Horst KierdorfAbstract:This paper reports a case of multiple osteochondromas affecting the Antlers and the left zygomatic bone of a free-ranging adult white-tailed buck (Odocoileus virginianus) from Georgia, USA. Along with a few postcranial bones, the Antlered cranium of the individual was found in a severely weathered condition and devoid of any soft tissue. The Antlers exhibited five pedunculated exostoses that were composed of cancellous bone and, in their peripheral portions, also mineralized cartilage. The largest of the exostoses, located on the right Antler, had a maximum circumference of 55 cm. The exostosis arising from the zygomatic bone was broad-based and much smaller than the exophytic outgrowths on the Antlers. Diagnosis of the exostoses as osteochondromas was based on their overall morphology, the normal bone structure in their stalk regions, and the continuity of their spongiosa and cortex with the respective components of the parent bones. Antleromas, i.e., pathological outgrowths developing on Antlers as a result of insufficient androgen production, were excluded in the differential diagnosis, based on (1) the apparent maturity and, except for the tumors, normal shape of the Antlers and (2) the fact that exostosis formation had also affected the zygomatic bone. Previously only a single case of solitary osteochondroma of an Antler has been described in the scientific literature. The case presented here is the first report of multiple osteochondromas in a deer. As Antlers are regularly collected as trophies, and huge numbers of them are critically inspected each year, the fact that thus far only two cases of Antler osteochondromas have been reported suggests that these tumors are very rare.
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element concentrations and element ratios in Antler and pedicle bone of yearling red deer cervus elaphus stags a quantitative x ray fluorescence study
Biological Trace Element Research, 2014Co-Authors: Uwe Kierdorf, Dieter Stoffels, Horst KierdorfAbstract:The present study compared the concentrations of different elements (Ca, P, Mg, Sr, Ba, K, S, Zn, Mn) as well as Ca/P, Ca/Mg, Sr/Ca, and Ba/Ca ratios in hard Antler and pedicle bone of yearling red deer stags (n = 11). Pedicles showed higher concentrations of calcium and phosphorus and a higher Ca/Mg ratio than Antlers, while Antlers exhibited higher concentrations of potassium, sulfur, and manganese as well as higher Ca/P, Sr/Ca, and Ba/Ca ratios. The findings indicate that Antlers are less mineralized and show less maturation of their bone mineral than pedicles. Antlers also showed a higher intrasample variation of mineralization than pedicles, which can be related to the shorter life span of the (deciduous) Antlers compared to the (permanent) pedicles. It is suggested that Antler bone formation is stopped before the theoretically possible degree of mineralization and mineral maturation is reached, resulting in Antler biomechanical properties (high bending strength and work to fracture) that are well suited for their role in intraspecific fighting. It is further suggested that the differences in Sr/Ca and Ba/Ca ratios of Antlers and pedicles are related to the dietary shift from milk to vegetation in combination with an increasing intestinal discrimination against Sr and Ba with age, resulting in a less marked difference in these ratios than would be expected based on the dietary shift alone. The findings of our study underscore the suitability of Antlers and pedicles as models of bone mineralization and the influence of different animal-related and/or external factors on this process.
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the structure of pedicle and hard Antler bone in the european roe deer capreolus capreolus a light microscope and backscattered electron imaging study
Journal of Anatomy, 2013Co-Authors: Uwe Kierdorf, Tomas Landetecastillejos, Santiago Gomez, Stefan Flohr, Horst KierdorfAbstract:Deer Antlers are deciduous bony structures that develop from permanent frontal outgrowths, the pedicles. While growth and bone architecture of Antlers have been studied in greater detail, information on pedicle formation and structure is scarce. The present study provides information on the structure of pedicle and hard Antler bone in the European roe deer. A pronounced seasonal variation in pedicle architecture was observed, with high porosity around Antler casting and a very compact bone structure during the hard Antler stage. These observations suggest a corresponding marked variation also in the biomechanical properties of the pedicles. The seasonally alternating extensive resorption and formation processes make the pedicles of older deer heavily remodeled structures. Pedicles increase in thickness by apposition of primary bone that subsequently becomes replaced by secondary osteons. The Antler cortex of roe deer is largely composed of a tubular framework of woven bone trabeculae with some remnants of mineralized cartilage, and primary osteons that have filled in the intertrabecular spaces. Secondary osteons are scarce, denoting little remodeling in Antlers, which can be related to their short lifespan. The occurrence of cement lines around primary osteons indicates resorption on the trabecular scaffold prior to infilling of the intertrabecular spaces. The outer cortex showed a higher autofluorescence and a more immature structure than the main cortex, suggesting that it was secondarily formed by periosteal activity. Pedicles and Antlers constitute a functional entity, and future histological and/or biomechanical studies should therefore consider both components of the cranial appendages.
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labeling studies on cortical bone formation in the Antlers of red deer cervus elaphus
Bone, 2013Co-Authors: Santiago Gomez, Andrés J. Garcia, Laureano Gallego, Uwe Kierdorf, Horst Kierdorf, Tomas Landetecastillejos, Salvador LunaAbstract:The formation and mineralization process of Antlers, which constitute the fastest growing bones in vertebrates, is still not fully understood. We used oxytetracycline injections to label different stages of bone formation in Antlers of 14 red deer between days 28 and 156 of Antler growth. Results show that initially a trabecular scaffold of woven bone is formed which largely replaces a pre-existing scaffold of mineralized cartilage. Lamellar bone is then deposited and from about day 70 onwards, primary osteons fill in the longitudinal tubes lined by the scaffold in a proximal to distal sequence. Mineral apposition rate (MAR) in early stages of primary osteon formation is very high (average 2.15 μm/d). Lower MARs were recorded for later stages of primary osteon formation (1.56 μm/d) and for the smaller secondary osteons (0.89 μm/d). Results suggest a peak in mineral demand around day 100 when the extent of mineralizing surfaces is maximal. A few secondary osteons were formed in a process of Antler modeling rather than remodeling, as it occurred simultaneously with formation of primary osteons. The degree of cortical porosity reflects a reduction in MAR during later stages of osteonal growth, whereas cortical thickness is determined earlier. Injections given when the Antlers were largely or completely clean from velvet produced no labels in Antler bone, strongly suggesting that Antlers are dead after velvet shedding. The rapidity of Antler mineralization and the short lifespan of Antlers make them an extraordinary model to assess the effects of chemicals impairing or promoting bone mineralization.
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deer Antlers a model of mammalian appendage regeneration an extensive review
Gerontology, 2011Co-Authors: Uwe Kierdorf, Horst KierdorfAbstract:Background: Compared with other vertebrate taxa, mammals possess a very limited capacity for appendage regeneration. The Antlers of deer are an exception in that they are periodically lost and fully regenerated throughout the life of an individual. Objective: In this paper we compare certain aspects of Antler regeneration with regenerative processes in other vertebrates. Methods: Review of the literature. Results: Recent studies suggest that Antler regeneration is a stem cell-based process and that these stem cells are located in the pedicle periosteum. There is evidence that signaling pathways known to operate during appendage regeneration in other vertebrates are also activated during Antler regeneration. There are, however, also differences between Antlers and other systems of epimorphic regeneration. Thus, contrary to amphibian limb regeneration, signaling from the wound epidermis appears not to be of crucial importance for Antler regeneration. Healing of the casting wound typically involves no or only minor scarring, making Antlers interesting subjects for researchers attempting to reduce scar formation during wound healing in humans. The fact that despite their enormous growth rate the Antlers of intact and castrated deer appear to be resistant to malignant transformation furthermore offers research opportunities for cancer biology. Conclusions: Studying Antler renewal as an example of mammalian appendage regeneration may provide crucial information for regenerative medicine to achieve its ultimate goal of stimulating limb regeneration in humans. A deeper understanding of the developmental mechanisms involved in Antler renewal can also be useful for controlling induced regeneration processes in mammals.
Tomas Landetecastillejos - One of the best experts on this subject based on the ideXlab platform.
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the structure of pedicle and hard Antler bone in the european roe deer capreolus capreolus a light microscope and backscattered electron imaging study
Journal of Anatomy, 2013Co-Authors: Uwe Kierdorf, Tomas Landetecastillejos, Santiago Gomez, Stefan Flohr, Horst KierdorfAbstract:Deer Antlers are deciduous bony structures that develop from permanent frontal outgrowths, the pedicles. While growth and bone architecture of Antlers have been studied in greater detail, information on pedicle formation and structure is scarce. The present study provides information on the structure of pedicle and hard Antler bone in the European roe deer. A pronounced seasonal variation in pedicle architecture was observed, with high porosity around Antler casting and a very compact bone structure during the hard Antler stage. These observations suggest a corresponding marked variation also in the biomechanical properties of the pedicles. The seasonally alternating extensive resorption and formation processes make the pedicles of older deer heavily remodeled structures. Pedicles increase in thickness by apposition of primary bone that subsequently becomes replaced by secondary osteons. The Antler cortex of roe deer is largely composed of a tubular framework of woven bone trabeculae with some remnants of mineralized cartilage, and primary osteons that have filled in the intertrabecular spaces. Secondary osteons are scarce, denoting little remodeling in Antlers, which can be related to their short lifespan. The occurrence of cement lines around primary osteons indicates resorption on the trabecular scaffold prior to infilling of the intertrabecular spaces. The outer cortex showed a higher autofluorescence and a more immature structure than the main cortex, suggesting that it was secondarily formed by periosteal activity. Pedicles and Antlers constitute a functional entity, and future histological and/or biomechanical studies should therefore consider both components of the cranial appendages.
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labeling studies on cortical bone formation in the Antlers of red deer cervus elaphus
Bone, 2013Co-Authors: Santiago Gomez, Andrés J. Garcia, Laureano Gallego, Uwe Kierdorf, Horst Kierdorf, Tomas Landetecastillejos, Salvador LunaAbstract:The formation and mineralization process of Antlers, which constitute the fastest growing bones in vertebrates, is still not fully understood. We used oxytetracycline injections to label different stages of bone formation in Antlers of 14 red deer between days 28 and 156 of Antler growth. Results show that initially a trabecular scaffold of woven bone is formed which largely replaces a pre-existing scaffold of mineralized cartilage. Lamellar bone is then deposited and from about day 70 onwards, primary osteons fill in the longitudinal tubes lined by the scaffold in a proximal to distal sequence. Mineral apposition rate (MAR) in early stages of primary osteon formation is very high (average 2.15 μm/d). Lower MARs were recorded for later stages of primary osteon formation (1.56 μm/d) and for the smaller secondary osteons (0.89 μm/d). Results suggest a peak in mineral demand around day 100 when the extent of mineralizing surfaces is maximal. A few secondary osteons were formed in a process of Antler modeling rather than remodeling, as it occurred simultaneously with formation of primary osteons. The degree of cortical porosity reflects a reduction in MAR during later stages of osteonal growth, whereas cortical thickness is determined earlier. Injections given when the Antlers were largely or completely clean from velvet produced no labels in Antler bone, strongly suggesting that Antlers are dead after velvet shedding. The rapidity of Antler mineralization and the short lifespan of Antlers make them an extraordinary model to assess the effects of chemicals impairing or promoting bone mineralization.
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do drastic weather effects on diet influence changes in chemical composition mechanical properties and structure in deer Antlers
Bone, 2010Co-Authors: Francisco Ceacero, Andrés J. Garcia, Yolanda Fierro, Tomas Landetecastillejos, J A Estevez, J D Currey, A CalatayudAbstract:We attempted to determine why after an exceptionally hard winter deer Antlers fractured more often than usual. We assessed mechanical properties, structural variables and mineral composition of deer Antlers grown in a game estate (LM) after freezing temperatures (late winter frosts, LWF), which resulted in high incidence of Antler fractures despite being grown later in the year, and those grown after a standard winter (SW). Within each year, specimens from broken and intact Antlers were assessed. LWF was associated with reduced impact energy (U) and somewhat reduced work to peak force (W), Young's modulus (E) and physical density, as well as cortical thickness. LWF was associated with considerably increased Si and reduced Na. In each year, broken Antlers had lower Mn, P and physical density, and they had more Na and B than unbroken Antlers. Because no such effect was found in farmed deer fed whole meal, and because freezing in plants usually produces an increase in Si content, which in turn reduces Mn, it is likely that LWF produced a diet rich in Si and low in Mn. Because Antlers are grown transferring calcium phosphate from the own skeleton and Ca/P levels were slightly reduced, it seems likely that Mn reduction may have increased Antler fractures. A comparison between farm deer and those in another game estate (LI) also shows a link between lower Mn content and lower W. Thus, small changes in minor bone minerals, probably induced by diet, may have marked effects in mechanical properties of bone.
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biometrics testosterone cortisol and Antler growth cycle in iberian red deer stags cervus elaphus hispanicus
Reproduction in Domestic Animals, 2010Co-Authors: E Gasparlopez, Francisco Ceacero, Laureano Gallego, Tomas Landetecastillejos, J A Estevez, Andrés J. GarciaAbstract:Contents In this article, we aimed to describe the changes related to mating season in red deer, especially those related to Antler growth, body condition score, testosterone and cortisol. Antler growth was studied in 17 Iberian red deer males, including body weight, Antler length, biometric measures and testosterone and cortisol determination during 15 months. Body weight, body condition score, thoracic perimeter (TP), neck perimeter (NL) and testicular diameter (TD) showed the highest values immediately before mating season (autumn), decreased during it and remained constant at winter. Antler growth lasted 158 days and produced Antlers with a final length of 80.8 ± 2.0 cm. Testosterone and cortisol showed seasonal changes with maximum values at September and May, respectively. Final Antler size was related positively to cranial longitude, TP, NL, TD and body weight at casting time. No relationship between weight loss during precedent mating season and current Antler size was found, but spring recovery weight was positively related to final Antler size. Final length was related to the descent in testosterone values during previous mating season and to body weight before it. Spring recovery weight was related to relative weight loss during previous mating season. These results suggest that there is no relationship between the reproductive effort performed during one season and the next year size of the Antler. In contrast, Antler size was positively related to spring recovery weight, in the sense that those deer that recover a higher percentage of body weight at the early stages of Antler growth develop higher Antlers.
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the mechanical properties of red deer Antler bone when used in fighting
The Journal of Experimental Biology, 2009Co-Authors: J D Currey, Francisco Ceacero, Andrés J. Garcia, Tomas Landetecastillejos, J A Estevez, Augusto Olguin, Laureano GallegoAbstract:We assessed the hydration state of Antlers and its effect on Antler mechanical properties compared with wet femur. Red deer Antlers were removed from the head at various times, from a few days after velvet shedding till late in the season, and weighed weekly until after casting time. Antlers cut just after losing their velvet lost weight rapidly in the first few weeks, then settled down and changed weight very little, the latter changes correlating with air relative humidity. Antlers cut later showed little weight change at any time. The water content of cortical and trabecular parts of the contralateral Antler was assessed after cutting. Most of the weight loss was from the cancellous, not the cortical, part of the Antler. Wet and dry specimens from the Antlers, and wet specimens from deer femora, were tested mechanically. Compared with wet bone, wet Antler had a much lower modulus of elasticity and bending strength, but a higher work to fracture. Compared with wet bone, dry Antler showed a somewhat lower Young's modulus, but a considerably higher bending strength and a much higher work to fracture. The impact energy absorption of dry Antler was much greater than that of wet bone. In red deer, the Antler is effectively dry during its use in fights, at least in southern Spain. In addition, dry Antler, compared with ordinary bone, shows mechanical properties that suit it admirably for its fighting function.
Andrés J. Garcia - One of the best experts on this subject based on the ideXlab platform.
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labeling studies on cortical bone formation in the Antlers of red deer cervus elaphus
Bone, 2013Co-Authors: Santiago Gomez, Andrés J. Garcia, Laureano Gallego, Uwe Kierdorf, Horst Kierdorf, Tomas Landetecastillejos, Salvador LunaAbstract:The formation and mineralization process of Antlers, which constitute the fastest growing bones in vertebrates, is still not fully understood. We used oxytetracycline injections to label different stages of bone formation in Antlers of 14 red deer between days 28 and 156 of Antler growth. Results show that initially a trabecular scaffold of woven bone is formed which largely replaces a pre-existing scaffold of mineralized cartilage. Lamellar bone is then deposited and from about day 70 onwards, primary osteons fill in the longitudinal tubes lined by the scaffold in a proximal to distal sequence. Mineral apposition rate (MAR) in early stages of primary osteon formation is very high (average 2.15 μm/d). Lower MARs were recorded for later stages of primary osteon formation (1.56 μm/d) and for the smaller secondary osteons (0.89 μm/d). Results suggest a peak in mineral demand around day 100 when the extent of mineralizing surfaces is maximal. A few secondary osteons were formed in a process of Antler modeling rather than remodeling, as it occurred simultaneously with formation of primary osteons. The degree of cortical porosity reflects a reduction in MAR during later stages of osteonal growth, whereas cortical thickness is determined earlier. Injections given when the Antlers were largely or completely clean from velvet produced no labels in Antler bone, strongly suggesting that Antlers are dead after velvet shedding. The rapidity of Antler mineralization and the short lifespan of Antlers make them an extraordinary model to assess the effects of chemicals impairing or promoting bone mineralization.
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do drastic weather effects on diet influence changes in chemical composition mechanical properties and structure in deer Antlers
Bone, 2010Co-Authors: Francisco Ceacero, Andrés J. Garcia, Yolanda Fierro, Tomas Landetecastillejos, J A Estevez, J D Currey, A CalatayudAbstract:We attempted to determine why after an exceptionally hard winter deer Antlers fractured more often than usual. We assessed mechanical properties, structural variables and mineral composition of deer Antlers grown in a game estate (LM) after freezing temperatures (late winter frosts, LWF), which resulted in high incidence of Antler fractures despite being grown later in the year, and those grown after a standard winter (SW). Within each year, specimens from broken and intact Antlers were assessed. LWF was associated with reduced impact energy (U) and somewhat reduced work to peak force (W), Young's modulus (E) and physical density, as well as cortical thickness. LWF was associated with considerably increased Si and reduced Na. In each year, broken Antlers had lower Mn, P and physical density, and they had more Na and B than unbroken Antlers. Because no such effect was found in farmed deer fed whole meal, and because freezing in plants usually produces an increase in Si content, which in turn reduces Mn, it is likely that LWF produced a diet rich in Si and low in Mn. Because Antlers are grown transferring calcium phosphate from the own skeleton and Ca/P levels were slightly reduced, it seems likely that Mn reduction may have increased Antler fractures. A comparison between farm deer and those in another game estate (LI) also shows a link between lower Mn content and lower W. Thus, small changes in minor bone minerals, probably induced by diet, may have marked effects in mechanical properties of bone.
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biometrics testosterone cortisol and Antler growth cycle in iberian red deer stags cervus elaphus hispanicus
Reproduction in Domestic Animals, 2010Co-Authors: E Gasparlopez, Francisco Ceacero, Laureano Gallego, Tomas Landetecastillejos, J A Estevez, Andrés J. GarciaAbstract:Contents In this article, we aimed to describe the changes related to mating season in red deer, especially those related to Antler growth, body condition score, testosterone and cortisol. Antler growth was studied in 17 Iberian red deer males, including body weight, Antler length, biometric measures and testosterone and cortisol determination during 15 months. Body weight, body condition score, thoracic perimeter (TP), neck perimeter (NL) and testicular diameter (TD) showed the highest values immediately before mating season (autumn), decreased during it and remained constant at winter. Antler growth lasted 158 days and produced Antlers with a final length of 80.8 ± 2.0 cm. Testosterone and cortisol showed seasonal changes with maximum values at September and May, respectively. Final Antler size was related positively to cranial longitude, TP, NL, TD and body weight at casting time. No relationship between weight loss during precedent mating season and current Antler size was found, but spring recovery weight was positively related to final Antler size. Final length was related to the descent in testosterone values during previous mating season and to body weight before it. Spring recovery weight was related to relative weight loss during previous mating season. These results suggest that there is no relationship between the reproductive effort performed during one season and the next year size of the Antler. In contrast, Antler size was positively related to spring recovery weight, in the sense that those deer that recover a higher percentage of body weight at the early stages of Antler growth develop higher Antlers.
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the mechanical properties of red deer Antler bone when used in fighting
The Journal of Experimental Biology, 2009Co-Authors: J D Currey, Francisco Ceacero, Andrés J. Garcia, Tomas Landetecastillejos, J A Estevez, Augusto Olguin, Laureano GallegoAbstract:We assessed the hydration state of Antlers and its effect on Antler mechanical properties compared with wet femur. Red deer Antlers were removed from the head at various times, from a few days after velvet shedding till late in the season, and weighed weekly until after casting time. Antlers cut just after losing their velvet lost weight rapidly in the first few weeks, then settled down and changed weight very little, the latter changes correlating with air relative humidity. Antlers cut later showed little weight change at any time. The water content of cortical and trabecular parts of the contralateral Antler was assessed after cutting. Most of the weight loss was from the cancellous, not the cortical, part of the Antler. Wet and dry specimens from the Antlers, and wet specimens from deer femora, were tested mechanically. Compared with wet bone, wet Antler had a much lower modulus of elasticity and bending strength, but a higher work to fracture. Compared with wet bone, dry Antler showed a somewhat lower Young's modulus, but a considerably higher bending strength and a much higher work to fracture. The impact energy absorption of dry Antler was much greater than that of wet bone. In red deer, the Antler is effectively dry during its use in fights, at least in southern Spain. In addition, dry Antler, compared with ordinary bone, shows mechanical properties that suit it admirably for its fighting function.
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seasonal changes in plasma leptin concentration related to Antler cycle in iberian red deer stags
Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 2009Co-Authors: E Gasparlopez, Laureano Gallego, Tomas Landetecastillejos, J A Estevez, J Casabiell, L F De La Cruz, Andrés J. GarciaAbstract:The aim of this study is to describe the leptin cycle in male Iberian red deer (Cervus elaphus hispanicus) and relate it to Antler and testosterone cycles. An additional aim is to assess the relationship between the plasma leptin concentration during Antlers’ growth and their final size. Therefore, blood from 21 Iberian red deer males was sampled monthly to analyse leptin and testosterone. At the same time the deer were weighed and their body condition was assessed. The length of Antlers was measured every 2 weeks and, after casting, their final length and perimeters were taken. Leptin showed a seasonal cycle, with a peak in June that decreased as testosterone increased. Low values were observed in autumn, winter and early spring. The relationship observed between leptin and body mass or body condition score was different in spring, when plasma testosterone concentration is low, than in autumn, when testosterone increases. Leptin peak amplitude was positively related to final Antler size. In conclusion, the relationship between leptin and body mass and body condition score changes through the year, possibly due to the influence of androgens and photoperiod. There was a positive relationship between plasma concentration of leptin during Antler growth and final Antler length.
Laureano Gallego - One of the best experts on this subject based on the ideXlab platform.
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labeling studies on cortical bone formation in the Antlers of red deer cervus elaphus
Bone, 2013Co-Authors: Santiago Gomez, Andrés J. Garcia, Laureano Gallego, Uwe Kierdorf, Horst Kierdorf, Tomas Landetecastillejos, Salvador LunaAbstract:The formation and mineralization process of Antlers, which constitute the fastest growing bones in vertebrates, is still not fully understood. We used oxytetracycline injections to label different stages of bone formation in Antlers of 14 red deer between days 28 and 156 of Antler growth. Results show that initially a trabecular scaffold of woven bone is formed which largely replaces a pre-existing scaffold of mineralized cartilage. Lamellar bone is then deposited and from about day 70 onwards, primary osteons fill in the longitudinal tubes lined by the scaffold in a proximal to distal sequence. Mineral apposition rate (MAR) in early stages of primary osteon formation is very high (average 2.15 μm/d). Lower MARs were recorded for later stages of primary osteon formation (1.56 μm/d) and for the smaller secondary osteons (0.89 μm/d). Results suggest a peak in mineral demand around day 100 when the extent of mineralizing surfaces is maximal. A few secondary osteons were formed in a process of Antler modeling rather than remodeling, as it occurred simultaneously with formation of primary osteons. The degree of cortical porosity reflects a reduction in MAR during later stages of osteonal growth, whereas cortical thickness is determined earlier. Injections given when the Antlers were largely or completely clean from velvet produced no labels in Antler bone, strongly suggesting that Antlers are dead after velvet shedding. The rapidity of Antler mineralization and the short lifespan of Antlers make them an extraordinary model to assess the effects of chemicals impairing or promoting bone mineralization.
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biometrics testosterone cortisol and Antler growth cycle in iberian red deer stags cervus elaphus hispanicus
Reproduction in Domestic Animals, 2010Co-Authors: E Gasparlopez, Francisco Ceacero, Laureano Gallego, Tomas Landetecastillejos, J A Estevez, Andrés J. GarciaAbstract:Contents In this article, we aimed to describe the changes related to mating season in red deer, especially those related to Antler growth, body condition score, testosterone and cortisol. Antler growth was studied in 17 Iberian red deer males, including body weight, Antler length, biometric measures and testosterone and cortisol determination during 15 months. Body weight, body condition score, thoracic perimeter (TP), neck perimeter (NL) and testicular diameter (TD) showed the highest values immediately before mating season (autumn), decreased during it and remained constant at winter. Antler growth lasted 158 days and produced Antlers with a final length of 80.8 ± 2.0 cm. Testosterone and cortisol showed seasonal changes with maximum values at September and May, respectively. Final Antler size was related positively to cranial longitude, TP, NL, TD and body weight at casting time. No relationship between weight loss during precedent mating season and current Antler size was found, but spring recovery weight was positively related to final Antler size. Final length was related to the descent in testosterone values during previous mating season and to body weight before it. Spring recovery weight was related to relative weight loss during previous mating season. These results suggest that there is no relationship between the reproductive effort performed during one season and the next year size of the Antler. In contrast, Antler size was positively related to spring recovery weight, in the sense that those deer that recover a higher percentage of body weight at the early stages of Antler growth develop higher Antlers.
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the mechanical properties of red deer Antler bone when used in fighting
The Journal of Experimental Biology, 2009Co-Authors: J D Currey, Francisco Ceacero, Andrés J. Garcia, Tomas Landetecastillejos, J A Estevez, Augusto Olguin, Laureano GallegoAbstract:We assessed the hydration state of Antlers and its effect on Antler mechanical properties compared with wet femur. Red deer Antlers were removed from the head at various times, from a few days after velvet shedding till late in the season, and weighed weekly until after casting time. Antlers cut just after losing their velvet lost weight rapidly in the first few weeks, then settled down and changed weight very little, the latter changes correlating with air relative humidity. Antlers cut later showed little weight change at any time. The water content of cortical and trabecular parts of the contralateral Antler was assessed after cutting. Most of the weight loss was from the cancellous, not the cortical, part of the Antler. Wet and dry specimens from the Antlers, and wet specimens from deer femora, were tested mechanically. Compared with wet bone, wet Antler had a much lower modulus of elasticity and bending strength, but a higher work to fracture. Compared with wet bone, dry Antler showed a somewhat lower Young's modulus, but a considerably higher bending strength and a much higher work to fracture. The impact energy absorption of dry Antler was much greater than that of wet bone. In red deer, the Antler is effectively dry during its use in fights, at least in southern Spain. In addition, dry Antler, compared with ordinary bone, shows mechanical properties that suit it admirably for its fighting function.
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seasonal changes in plasma leptin concentration related to Antler cycle in iberian red deer stags
Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 2009Co-Authors: E Gasparlopez, Laureano Gallego, Tomas Landetecastillejos, J A Estevez, J Casabiell, L F De La Cruz, Andrés J. GarciaAbstract:The aim of this study is to describe the leptin cycle in male Iberian red deer (Cervus elaphus hispanicus) and relate it to Antler and testosterone cycles. An additional aim is to assess the relationship between the plasma leptin concentration during Antlers’ growth and their final size. Therefore, blood from 21 Iberian red deer males was sampled monthly to analyse leptin and testosterone. At the same time the deer were weighed and their body condition was assessed. The length of Antlers was measured every 2 weeks and, after casting, their final length and perimeters were taken. Leptin showed a seasonal cycle, with a peak in June that decreased as testosterone increased. Low values were observed in autumn, winter and early spring. The relationship observed between leptin and body mass or body condition score was different in spring, when plasma testosterone concentration is low, than in autumn, when testosterone increases. Leptin peak amplitude was positively related to final Antler size. In conclusion, the relationship between leptin and body mass and body condition score changes through the year, possibly due to the influence of androgens and photoperiod. There was a positive relationship between plasma concentration of leptin during Antler growth and final Antler length.
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population management and bone structural effects in composition and radio opacity of iberian red deer cervus elaphus hispanicus Antlers
European Journal of Wildlife Research, 2008Co-Authors: Francisco Ceacero, Andrés J. Garcia, Tomas Landetecastillejos, J A Estevez, Laureano GallegoAbstract:Antlers are costly bone structures whose size and external characteristics are influenced by nutrition, climatic variability, and other factors. In this study, we examined the effects of a well-managed captive population vs unmanaged free-ranging herds (greatly differing in food availability and energetic and immunological expenditures) on Antler structural characteristics of Iberian red deer. We assessed the effect of management and sample position in the Antler on cortical bone depth, bone mineral and protein content, and radiographic bone opacity. Cortical bone depth and mineral percent was greater in captive animals on greater food availability and lower energetic and immunological expenditures. After removing the inverse relationship with mineral content in the model, protein percent was also higher in Antlers from captive than in those from free-ranging deer. Management system also influenced radio-opacity indirectly as interaction with other factors and cortical bone depth effects. Structural properties also differed between Antler points that are very close in the Antler and seem to differ only in the role they play. In conclusion, captive management can affect Antler structure and composition, possibly as a result of different availability of food and immunological costs.