Acta Veterinaria Hungarica 46 (3) (1998)
Ecologically sound management
Management of indigenous North American deer at the end of the XXth century in relation to large predators and primary productivity.
M. Crete and C. Daigle
Ecologically sound management: Aspects of modern sustainable deer farming systems.
A. J. Pearse and K. R. Drew
Genetics and reproduction
Genetic analysis of farmed deer hybrids.
M. L. Tate, R. M. Anderson, K. M. McEwan, G. J. Goosen and A. J. Pearse
Photoperiodmelatonin relay in deer.
G. A. Lincoln
Feeding strategies and nutrition
The influence of sexual dimorphism in body size and mouth morphology on diet selection and sexual segregation in cervids.
F. J. Pérez-Barbería and I. J. Gordon
Growth, voluntary food intake and digestion in farmed temperate and tropical deer.
T. N. Barry, P. R. Wilson and G. Semiadi
Health, disease and welfare
Deer health and disease.
C. G. Mackintosh
The welfare of deer.
P. J. Goddard
Acta Veterinaria Hungarica 46 (3), p. 313 (1998)
MANAGEMENT OF INDIGENOUS NORTH AMERICAN DEER AT THE END OF THE XXTH CENTURY IN RELATION TO LARGE PREDATORS AND PRIMARY PRODUCTIVITY
M. Crete1, 2 and C. Daigle1
1Ministere de l’Environnement et de la Faune, Service de la Faune Terrestre, 150 Boul. René-Lévesque Est, Québec, Qc G1R 4Y1 Canada; 2Université Laval, Département de Biologie, Sainte-Foy, Qc G1K 7P4, Canada
Five deer species occupy North America: caribou (3.6 × 106 individuals), moose (1.1 × 106), white-tailed deer (28.5 × 106), mule deer (5.0 × 106) and wapiti (1.1 × 106). Caribou characterise the north of the boreal forest and the tundra, whereas moose dominate in coniferous and mixed forests growing further south. White-tailed deer are typical of the deciduous forests of the east while mule deer replace them in the mountainous terrain of the west. Wapiti possess the smallest range, mostly adjacent to the prairies to the west. The two specialised deer predators show a reduced distribution: wolves are almost restricted to Canada, and cougar to the mule deer range. We determined the current status of each species with the help of a questionnaire mailed to all jurisdictions harbouring deer. Most reports of threatened populations concerned caribou whereas many jurisdictions declared overabundance of white-tailed deer and wapiti. Hunting was allowed for all species when they abounded in a jurisdiction. Hunters harvested annually 7.0 × 106 deer on the continent, 87% being white-tailed deer. The two species that caused most conflicts with humans had the highest harvest rate: 1617%. In terms of biomass, white-tailed deer and wapiti yielded the highest harvests, with 55 and 39 kg × km2 of range, respectively. The average standing biomass of deer in winter ranged between 28 kg × km2 in Nevada to 901 kg × km2 in Indiana. The lowest standing biomasses occurred in the boreal forest (predators), in the prairies (agriculture) and in the south-west (aridity), and the highest ones, in the south-east, although only white-tailed deer is present. The current abundance of deer in North America parallels, in general, the primary production of the landscape, but predators and human activity modify this pattern.
Key words: Deer species, caribou, moose, white-tailed deer, mule deer, wapiti, North America, abundance, management, predators, hunting, harvest, standing biomass
Acta Veterinaria Hungarica 46 (3), pp. 315-328 (1998)
ECOLOGICALLY SOUND MANAGEMENT: ASPECTS OF MODERN SUSTAINABLE DEER FARMING SYSTEMS
A. J. Pearse* and K. R. Drew
AgResearch, Deer Research Group, Invermay Agricultural Centre,
Private Bag 50034, Mosgiel, New Zealand
Modern deer farming systems have become increasingly intensive allowing strategic feeding for production and genetic improvement programmes. Meeting feeding standards that account for changing nutritional demands related to seasonality and reproductive state is critical. As the industry matures there is a growing awareness of the balance between retaining natural behaviour in producing breeding stock on larger extensive holdings and intensification systems for performance in young stock. Stocking rates are critical determinants of success as land use and capability needs are matched with an increasing stratification of stock type and purpose. Food product safety and welfare considerations of farmed deer are being driven by consumer demands. Farm quality assurance and codes of practice are developing to ensure that deer farming meets and exceeds international expectations of land use and deer welfare in modern deer farming systems.
Key words: Farmed deer, land use, feed requirements, sustainability, management
* Phone: 643 489 3809, fax: 643 489 9038, e-mail: firstname.lastname@example.org
Acta Veterinaria Hungarica 46 (3), pp. 329-340 (1998)
GENETIC ANALYSIS OF FARMED DEER HYBRIDS
M. L. Tate1*, R. MA. Anderson1, K. M. McEwan2**, G. J. Goosen2 and A. J. Pearse2
1AgResearch Molecular Biology Unit, Department of Biochemistry, University of Otago,
P.O. Box 56, Dunedin, New Zealand;
2AgResearch, Invermay Agricultural Centre,
P.O. Box 50034, Mosgiel, New Zealand
Molecular methods which identify species-specific genetic markers are valuable for identification and genetic analysis of hybrid deer. We have used a variety of molecular techniques to compare Pere Davids deer Elaphurus davidianus, red deer Cervus elaphus scotticus and North American wapiti C. e. manatobensis. In total, these analyses have identified over 300 markers in which Pere Davids deer sires are distinct from farmed red deer and over 100 markers in which wapiti sires differ from red deer. Subsets of these markers have been used to identify hybrids on farms, and to estimate the proportion of red deer and wapiti in hybrid animals. Analysis of the segregation of the species-specific alleles in 352 backcross 1 Pere Davids, 3 red deer hybrids has produced a deer genetic linkage map which describes the chromosomal grouping and order of the markers. Correlation of the variability in phenotypic traits with marker segregation in the backcross hybrids has located genes which influence variation in gestation length, pedicle-initiation, birth weight, growth rate and a variety of morphological traits in Pere Davids deer × red deer hybrids. Such genetic analyses can now be extended, using new marker technologies, to more closely related taxa, such as farmed red deer and wapiti hybrids, and potentially analyse natural hybrid zones.
Key words: Farmed deer, hybridisation, genetic markers, Cervus elaphus, Elaphurus davidianus
* Phone: 64 3 479 7682, fax: 64 3 477 5413, e-mail: email@example.com
** Phone: 64 3 489 3809, fax: 64 3 489 9037
Acta Veterinaria Hungarica 46 (3), pp. 341-356 (1998)
PHOTOPERIODMELATONIN RELAY IN DEER
G. A. Lincoln*
MRC Reproductive Biology Unit, Centre for Reproductive Biology,
37 Chalmers Street, Edinburgh EH3 9EW, UK
Long-lived mammals from cold and temperate climates, including many species of deer, express overt cycles in reproduction, moulting, fattening and other characteristics. These cycles persist under constant conditions, but are normally induced and entrained by the annual cycle in daylength. The photoperiod-relay involves the eyes, the suprachiasmatic nuclei (SCN) of the hypothalamus and the pineal gland which secretes melatonin only at night. The duration of daily melatonin secretion varies with daylength and provides an internal endocrine signal for the time-of-year. In deer, treatments with melatonin induce phase-shifts in all overt seasonal rhythms. Melatonin is thought to act on specific target cells in the brain and pituitary gland which express high affinity melatonin receptors. In sheep, micro-implants of melatonin placed in the mediobasal hypothalamus (MBH) induce a complete spectrum of short-day responses, while surgical disconnection of the pituitary gland blocks all photoperiodic responses except for the regulation of prolactin. These observations support the 'dual-site hypothesis' that melatonin acts primarily in the MBH to control gonadotrophin secretion and the reproductive axis, but acts primarily in the pituitary gland via the pars tuberalis, to control prolactin secretion and the pelage axis. This differential regulation helps explains how prolactin can be the hormone of summer in all photoperiodic ungulates irrespective of their seasonal breeding characteristics.
Key words: Circannual rhythms, gonadotrophins, melatonin receptors, prolactin, seasonal breeding
* Correspondence: Fax: 0131-228-5571, e-mail: firstname.lastname@example.org
Acta Veterinaria Hungarica 46 (3), pp. 357-367 (1998)
THE INFLUENCE OF SEXUAL DIMORPHISM IN BODY SIZE AND MOUTH MORPHOLOGY ON DIET SELECTION AND SEXUAL SEGREGATION IN CERVIDS
F. J. Pérez-Barbería and I. J. Gordon*
The Macaulay Land Use Research Institute, Craigiebuckler, AB15 8QH Aberdeen,
Scotland, United Kingdom
In mammals patterns of food resource distribution influence female distribution, leading to aggregation and favouring the evolution of a polygynous mating system. Under polygyny, sexual selection favours an increase of the male body size, since larger bodied males have competitive advantage in fights for mates. As a result, sexual body size dimorphism is a general rule in polygynous artiodactyls and is correlated with the degree of polygyny. Sex differences in body size lead to differences in energy requirements and food selection between the sexes. This has led to the sexual size dimorphism hypothesis being used to explain sexual segregation in ungulates, although from the available studies, it is not possible to deduce a consistent pattern between sexes in the use of forage of different abundance or quality. Two other groups of hypotheses have been put forward to explain sexual segregation in ungulates. These are based on reproductive strategy and social factors, both of which are independent of body size. The mechanistic explanation for differences in food selection ability and intake rate between animals of different body size and how this can lead to an understanding of the sex differences in diet and sexual segregation, both of which are intimately linked, is discussed.
Key words: Allometry, cervids, diet selection, sexual dimorphism, sexual segregation
Acta Veterinaria Hungarica 46 (3), pp. 369-380 (1998)
GROWTH, VOLUNTARY FOOD INTAKE AND DIGESTION IN FARMED TEMPERATE AND TROPICAL DEER
T. N. Barry1, p. R. Wilson2 and G. Semiadi3
1Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand;
2Institute of Veterinary, Animal and Biomedical Sciences,
Massey University, Palmerston North, New Zealand;
3Puslitbang Biologi LIPI,
Gedung Widya Satwaloka, 16162 Bogor, Indonesia
Growth and voluntary feed intake (VFI) in grazing temperate farmed deer species are influenced by the feeding value of the forage and the stage of the deers seasonal cycle. Liveweight gain (LWG) of growing red deer was greater when perennial ryegrass (0.80)/white clover (0.20) pasture was grazed at 10 cm than 5 cm surface height, but venison production by one year of age was still low. Chicory and red clover were of superior feeding value for deer than perennial ryegrass-based pastures, increasing LWG of young red and hybrid (0.25 elk; 0.75 red deer) deer during summer and autumn, due to higher VFI and to higher organic matter digestibility. Relative to perennial ryegrass, chicory disintegrated faster in the rumen, with very low rumination time and faster rumen outflow rates of liquid and particulate matter. Inputs of red clover and chicory substantially increased venison carcass weights at one year of age from grazing red and hybrid stags. In indoor pen feeding studies, red deer were shown to have a seasonal cycle of digestive function, with greater rumen mean retention time (MRT) and greater rates of rumen ammonia production in summer than in winter. It was deduced that the purpose of the digestive cycle was to maintain apparent digestibility constant as VFI increased during summer. Tropical sambar deer were also shown to have seasonal cycles in growth and VFI that were of reduced amplitude compared with red deer. Peak VFI and growth occurred in autumn and minimum VFI and growth occurred in spring. Feed conversion (kg DM eaten/kg LWG) was more efficient for sambar than for red deer, due to lower VFI and lower heat production, but there was no difference between species in digestive efficiency.
Key words: Red deer, sambar deer, forages, growth, voluntary feed intake, rumen digestion
Acta Veterinaria Hungarica 46 (3), pp. 381-394 (1998)
DEER HEALTH AND DISEASE
C. G. Mackintosh
AgResearch, Invermay Agricultural Centre, Private Bag 50034, Mosgiel, New Zealand
This paper describes the most significant diseases of farmed deer which have emerged over the last 30 or so years. It describes their characteristic signs, how control measures have evolved, their current status and gives an indication of future diagnostic and control measures. Overall, it shows that wild deer brought into a farming environment have developed some of the production limiting diseases which affect sheep and cattle, such as parasitism and trace element deficiencies. In addition, farmed deer are susceptible to potentially fatal diseases such as tuberculosis, malignant catarrhal fever and yersiniosis. A disease which has recently emerged and has the potential to be more serious than any of the above is Johnes disease. In North America, Chronic Wasting Disease occurs in captive and wild deer in only two states but has the potential to be a serious threat to wild and farmed deer elsewhere if it spreads. The zoonotic risks of diseases affecting deer are discussed, as well as stress, welfare and deer restraint. The productivity of farmed deer can be maximised by using a well-designed deer health programme integrated with good management and feeding.
Key words: Deer, diseases, malignant catarrhal fever, tuberculosis, parasitism, yersiniosis, Johnes disease, Chronic Wasting Disease, zoonoses, restraint, stress, copper deficiency, health programmes
Acta Veterinaria Hungarica 46 (3), pp. 395-404 (1998)
THE WELFARE OF DEER
P. J. Goddard
Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen, AB15 8QH, U. K.
Recent research on the welfare of farmed deer, as for other species, has addressed issues relating to transport, housing and slaughter. While most studies have continued to use a behavioural and physiological approach, new methods of assessing welfare need to consider aspects of cognition and awareness, which are not so easily assessed. It is suggested that a systems-based analysis may be one way to obtain a view of welfare from an animal-centred position. Incorporating an economic perspective could indicate whether consumer choice or legislation would be more likely to lead to higher standards.
Key words: Welfare, stress, deer, behaviour, physiology