Effects of various ovulation induction stimuli in alpacas and llamas

The signs of oestrus in alpaca (Lama pacos) and llama (L. glama) are described. The results of attempts to induce ovulation by various methods (copulation by fertile and sterile males; the use of exogenous hormones; the 'male effect'; and insemination by alpaca and bovine semen) are presented. The phenomen of spontaneous ovulation is also discussed. Relations among the various mechanisms of ovulation stimuli, formation of a corpus luteum and levels and duration of peripheral progesterone are analysed. The terms 'induced or reflex' ovulation and 'spontaneous' ovulation need more careful definition. © 1994 Academic Press, Inc.