Influence of social status on ovarian function in farmed red deer (Cervus elaphus)

This study examines the effects of behavioural and environmental factors on ovarian function in red deer hinds. Patterns of postovulatory luteal progesterone secretion were investigated in groups of farmed red deer hinds following oestrus induced by progesterone administration and withdrawal. Hinds were held under conditions leading to low (Experiment 1, held in paddocks: 0.29 per animal/h) or high (Experiment 2, held in pens: 1.11 per animal/h) interaction rates, and progesterone was measured in jugular venous blood samples obtained daily for 14 days after ovulation. Plasma progesterone levels tended to differ with respect to dominance status in both experiments (p < 0.1). Progesterone levels were substantially lower following prolonged hot dry weather (mean 0.67 +/- SEM 0.03 ng/mL) than in a year of relatively typical climatic conditions (mean 1.63 +/- 0.04 ng/mL; p < 0.0005). Progesterone levels were not related to the body weight of the hinds, and were not affected by housing conditions leading to different interaction rates. We conclude that although there is a tendency for dominance status to affect ovarian function, as observed before, this relationship is obscured in farmed red deer where all animals in the herd enjoy a higher plane of nutrition and movements of individuals between groups confuse dominance relationships.