The Influence of Age and Season on the Activity of the Testes and Epididymides of the Fallow Deer, Dama Dama

Abstract

The growth and spermatogenic activity of the testes and epididymides offallow deer of determined age were studied through the year in a cross section of British herds. Full spermatogenic activity for all populations was first found at 16 months of age though overall growth of the testes continued into middle age. The physiological ability to effect fertile matings is, however, mediated by social forces. Until puberty, growth of the testes is continuous and independent of seasonal factors. Development of the epididymides parallels that of the testes. After puberty, there is a seasonal cycle of growth and regression of the testes and epididymides with maximum weights associated with the mating period (rut) in October/November. The fallow deer is shown to follow the pattern of other northern temperate deer and to differ in its pattern of spermatogenic activity from tropical deer, such as muntjac, living in Britain.

Induction of oestrus and ovulation in farmed fallow deer (Dama dama) by using progesterone and PMSG treatment

“…Therefore, poor copulation responses by the buck to highly synchronized oestrus could not account completely for the low pregnancy rate. It is possible that buck fertility was suboptimal 3 weeks before the natural rut, given that fallow bucks exhibit highly seasonal fertility (Chaplin & White, 1972;Asher et al, 1987). However, low pregnancy rates may also relate to progesterone/PMSG treatment effects on the does, as frequently postulated for sheep (e.g.…”

Seasonal changes of testicular parameters in southern pudu Pudu puda in relationship to circannual variation of its reproductive hormones

“…This hypothesis is supported by data from several boreal cervids in which there is a concise seasonal rut followed by a limited parturition period. In fallow deer, the maximal seasonal decline of testicular weight was around 85% (Chaplin and White 1972), in roe deer the testicular volume decreased by 84% (Stieve 1949) and in white-tailed deer and red deer the testes weight declined by 76% (Mirarchi et al 1977) and 75%, respectively (Lincoln 1971). In the tropical Eld's deer however, the scrotal circumference declined seasonally by 50% (Monfort et al 1993), but the temperate sika deer, the testes size decreased by only 36% (Suzuki et al 1992).…”

“…Cervid species inhabiting temperate zones are seasonal breeders and therefore their reproductive organs and concentrations of reproductive hormones exhibit annual changes which are synchronized by light. In male cervids, these changes were studied in red deer Cervus elaphus (Jaczewski 1954, Lincoln 1971, Hocherau-de Riviers and Lincoln 1978, fallow deer Dama dama (Chaplin andWhite 1972, Rolf andFischer 1990), roe deer Capreolus capreolus (Stieve 1949, Bubenik 1971, Schams and Barth 1982, Sempere 1990, sika deer Cervus nippon (Suzuki et al 1992), wapiti Cervus elaphus canadensis (Haigh et al 1984), white-tailed deer Odocoileus virginianus (Wislocki et al 1947, Mirarchi et al 1977 and several other species.…”

Circannual inter-relationships among reproductive hormones, gross morphometry, behaviour, ejaculate characteristics and testicular histology in Eld's deer stags (Cervus eldi thamin)

“…Aggressive behaviours in ungulates generally coincide with changes in sexual libido and mating behaviour in ungulates (Fraser, 1968 (Lincoln, 1971), fallow deer (Chaplin and White, 1972), black-tailed deer (West and Nordan, 1976), white-tailed deer (Wislocki, 1943), reindeer (Meschaks and Nordkvist, 1962) and chital (Loudon and Curlewis, 1988 Lincoln, 1981). Although the aetiology of sperm defects is unknown, degenerative processes presumably occur as an indirect consequence of the seasonal decline in gonadotrophin and testosterone secretion (Lincoln, 1981).…”