Abstract:
Proc. Aust. Soc. Anim. Prod. Vol. 18 PRODUCTION OF RED DEER IN A SUBTROPICAL ENVIRONMENT K.B. WOODFORD*, A. DUNNING+ and J.B. WINCH* Production parameters are presented for a herd of red deer (Cervus elaphus) farmed in a subtropical environment. Results include reproductive performance, These parameters have seasonal growth rates, carcass weights and mortalities. not been published for Australian conditions or subtropical latitudes. INTRODUCTION The European red deer (Cervus elaphus) is a seasonal breeding species with a natural environmental range from approximately 38% to 60% (Whitehead 1972). Kay (1985) reports that wild deer usually do best in open forest or forest edge habitats between latitudes 40� and 55O. Circannual rhythms of red geer include food intake and growth as well as reproduction (Kay 1979) and these cycles are entrained by seasonal changes in the hours of darkness (Suttie and Simpson 1985). Production characteristics of red deer have not previously been published for either Australian conditions or subtropical latitudes. XATERIALSANDXETHODS A production herd of 24 rising yearling hinds and two rising three year stags was established in October 1984 at University of Qld., Gatton College, The hinds were farm bred descendants of feral caught (Latitude 27O 36'S). animals from the Brisbane and Mary Valleys. These feral herds developed from releases of Scottish and German red deer in 1873 and 1874 (Bentley 1978). The two stags had dams of feral origin but were sired by a zoo bred stag of English origin. Female progeny were retained for breeding and male progeny, except for a few superior animals, were slaughtered at approximately 15 months of age. Climatic data for the period 1984 to 1988 are given in Table 1. Summer temperatures are potentially relevant in relation to calf survival and growth rates in young stock. Winter temperatures and wind run are relevant in relation to winter feed requirements, given that deer have relatively poor insulation and high winter feed requirements when farmed in cold climates (Fennessy et al. 1981). Frosts cause cessation of growth in the tropical pastures. The herd was run initially on 7 ha of lightly timbered ridge country. The predominant pasture species was green couch (Cynodon dactylon) with lesser quantities of rhodes grass (Chloris gayana) and green panic (Panicum maximum var trichoglume). A spray irrigation system was installed and kikuyu (Pennisetum clandestinum) was progressively introduced. Legume content was minimal. Pastures were fertilised with phosphate and up to 230 kg N/ha/annum. Frosts typically prevented any growth from June to August. As from December 1985 the deer unit included Javan rusa deer (Cervus timorensis) and by 1989 a total of 200 head was carried on an expanded area of 10 ha. On occasions the two species were run in the same paddock. Shortfalls of feed were met by feeding grain (barley or sorghum), and hay. An estimated 20-25 percent of total feed intake was provided as supplement. All deer were treated with oral anthelmintics as a preventive measure in October 1984 and calves born in 1987/88 were similarly treated in October 1988. Faecal samples were collected periodically to monitor internal parasites. * University of Queensland, Gatton College, Qld. 4343. 436 Proc. Aust. Soc. Anim. Prod. Vol. 18 Table 1 Climatic data, 1984-1988, Gatton College Deer were weighed at intervals of two to six weeks. Live weights were recorded Hot carcass weights were recorded for all off pasture witho-ut fasting. slaughtered animals and tissue depths were measured in the latter two years. Tissue depths were measured over the 12th rib at a point 16 cm from the midline Post mortem examinations were conducted on animals (Drew and Fennessy 1986). which died or were still born. RESULTS Estimates of seasonal growth rates (Table 2) were obtained from pooled data for the three cohorts of calves born during the summers of 1985/86, 1986/87 and 1987/88 but exclude one male that broke a leg as a yearling. These data were transformed to natural logarithms for statistical analyses, and the growth estimates reported here are back transformations of the means of the logarithms. Each season is defined as a three month period with the first season being autumn commencing on 1 March. Mean weights (2 s-d.) at this time were 32.7 (10.6) kg for males and 30.7 (8.6) kg for females. Table 2 Seasonal growth rates (g/d) Autumn Winter Spring Summer Five stags were retained to two years of age as potential breeders. Mean live weights (+s.d.) at one and two years of age (1 December) were 96.8 (12.7) kg and 142.4 (9.6) kg respectively. Comparative growth rates in the first and second years of life of these stags are shown in Table 3. Analysis of variance of logarithmically transformed data indicated that autumn and winter growth were both significantly lower (P~0.01) in the second year than the first. The differences in spring were non significant. Table 3 Comparative daily growth rates (g/d, mean & s.d.) of five stags in their first and second years Live weight and carcass parameters of 15 month stags are reported in Table 4. The dressing percentages are calculated as hot carcass weight for slaughtered animals divided by non fasted live weights of these animals. The imputed carcass weights are calculated by multiplying the average live weight for all . 437 Proc. Aust. Soc. Anim. Prod. Vol. 18 animals by the dressing percentage for the animals that were slaughtered. Table 4 Live weight and carcass parameters of 15 month stags Autumn live weights of hinds at the start of mating (1 April) are presented in Table 5. One hind from the 1983/84 cohort died from dystocia at 2 years of age and has been excluded from this analysis. Table 5 Autumn live weights (kg) of red hinds (mean + s-d.) Hind reproductive performance for 1985/86, 1986/87 and 1987/88 is presented in Table 6. Pregnancy rates are calculated as hinds producing live or dead calves divided by hinds at mating. Weaning rates are calculated as calves weaned divided by hinds at mating. Two hinds which conceived twins after hormonal treatment have been excluded from this analysis. Table 6 Reproductive performance of hinds Eleven calves (15% of all births) were either born dead or died in the first few days after birth. Two deaths were post mortemed as due to dystocia. Other post mortems were inconclusive owing to delays in finding the dead calves. Eight of the dead calves were born to the original low live weight hind cohort at their first calving. There were no deaths between weaning and 15 months. DISCUSSION Although statistically significant differences in seasonal growth rates were obtained, the seasonality of growth is, much less than has been reported in New Zealand. Adam and Asher (1986) reported winter growth rates in weaners of less 438 Proc, Aust. Soc, Anim. Prod, Vol. 18 Based on eight years of data at than one third those obtained in spring. Invermay Research Station, Moore et al. (1985) reported winter growth rates Drew (1976) ranging from 41-122 gJd in males and 16-63 g/d in females. reported winter growth1 rates of up to 100 g/d for deer fed barley based concentrates indoors. Although male calves grow faster than females in all seasons, the difference between the sexes increases after the first autumn, presumably due to androgenic factors. With both sexes it is apparent that overall growth rates The low autumn and are considerably lower in the second year than the first. winter growth rates in second yar males compare with virtual cessation of growth under New Zealand conditions at this time (Adam and Asher 1986). The carcass weights are considerably higher than those reported by Drew (1985) The carcass dressing percentages for the same age of animal in New Zealand. The tissue depths recorded in this are similar to New Zealand (Drew 1985). paper indicate carcass fat of approximately 5% (Drew and Fennessy 1986). Reproductive performance is better than New Asher and Adams (1985). The death rate in on these New Zealand survey farms. The influenced by results of the 1985/86 calving Zealand survey results reported by calves is similar to that recorded calf mortality rates are strongly by low live weight first calvers. The overall indication is that red deer are capable of performing in a subtropical environment at a level that is at least no worse than that of temperate environments. It seems likely that the subtropical environment has reduced the seasonality of growth as experienced in colder climates and higherlatitudes, There has been no obvious effect of environment on seasonal reproduction cycles. The authors acknowledge Mr J. McCosker for post mortem analyses and Mr for statistical advice and assistance. Some of the data presented paper were collected as part of the Deer Farming Systems Project funded by the Au&. Special Rural Research Council and the Qld. Deer Breeders' I. Bruce in this jointly Assoc. ADAM, J.L. and ASHER, G-W. (1986). In 'Proceedings of a Deer Course for Veterinarians', Deer Branch Course No. 3, p. 8, N.Z. Vet. Assoc. ASHER, G-W, and ADAM, J-L. (1985). In 'Biology of Deer Production', p. 217, editors P.F. Fennessy and K-R. Drew. (Roy. Soc. N.Z. : Wellington). 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