ENVIRONMENTAL CONSTRAINTS ON REPRODUCTIVE-PERFORMANCE OF FARMED DEER

Optimum reproductive efficiency of farmed deer is often constrained by apparent maladaptation of wild cervids to a given farm environment or components of that environment. Seasonal breeding amongst forest-frin ge species of northern temperate origin (e.g. red deer, fallow deer) b enefits the species within its natural range, but often creates misali gnment in southern temperate zones between the high nutritional demand s of lactation in summer and the earlier peak of pasture production an d quality occurring in spring. This can lead to increased calf mortali ty, decreased calf growth rates and depressed dam liveweights. Much em phasis has been placed on manipulating either pasture production patte rns or the timing of birth to create better synchrony between the two. The latter largely involves artificial manipulation of the timing of conceptions (e.g. melatonin treatment), but there may also be options for genetic selection of deer for earlier calving patterns. Tropical c ervid species farmed in temperate environments can exhibit either a se asonal reproduction (e.g. chital deer) or autumn-wintering calving pat terns (e.g. rusa deer), leading to high mortality of neonates (hypothe rmia, predation) under uncontrolled breeding management. However, ther e are simple management options to synchronise and shift calving patte rns to better align tropical species to temperate environments. The ef fects of chronic and acute stress on reproductive efficiency of farmed deer are often discussed but seldom demonstrated. Many farmed deer po pulations exhibit high pregnancy rates (i.e. > 90% females pregnant), indicating robust reproductive physiology and general habituation to t he farmed habitat. Low reproductive rates of pubertal red deer hinds i n some herds may be partly indicative of the effects of chronic stress , although other factors such as social facilitation and nutrition can not be discounted. While species of cervids that are used for farming generally display a high degree of behavioural plasticity, the farm en vironment and associated management practices may impinge on important components of the social environment. Thus, practices such as control led breeding (e.g. single-sire mating) and confinement during calving may have effects on reducing overall reproductive potential by disrupt ing social processes (e,g. dam-calf bonds). This highlights the paucit y of knowledge on the complexities of cervid behaviour and their impli cations in both wild and farmed deer.