Endocrine Causes of Seasonal and Lactational Anestrus in Farm Animals : A Seminar in the CEC Programme of Co-ordination of Research on Livestock Productivity and Management, held at the Institut fur T

Preface.- Preface.- Session I: Seasonal Anestrus in the Ewe.- Seasonal Anestrus Problems and Perspectives.- Endocrine Basis of Seasonal Anestrus in Sheep.- Genetics and Physiology of Follicle Recruitment and Maturation During Seasonal Anestrus.- Breed Differences in the Breeding Season in Sheep.- Light Control of Reproduction in the Ewe.- Effects of Melatonin on the Time of Onset of the Breeding Season in Different Breeds of Sheep.- Induction of Ovulation in Anestrous Ewes Using Gonadotrophins.- Induced Breeding in Anestrous Milking Ewes of Dairy Breeds: Comparison of Norgestomet, Medroxyprogesterone and Fluorogestone in Two Regimes of PMSG.- Discussion.- Session II: Seasonal Anestrus in the Sow and Mare.- Stimulation of Ovarian Activity in the Pony Mare during Winter Anestrus.- Practical Control of Anestrus in Thoroughbred Broodmares.- Seasonal Anestrus in Wild Sows.- Photoperiod and Fertility in the Pig.- Discussion.- Session III: Lactational Anestrus in the Pig.- Hypothalamic-Pituitary-Ovarian Responses to Weaning Retrospective Evidence for the Cause of Lactational Anestrus?.- Endocrine Interactions During Lactational Anestrus in Sows.- Relevance of Prolactin to Lactational and Post-Weaning Anestrus in the Sows.- Effects of Bromocriptine Treatment During Lactational Anestrus in Pigs.- Discussion.- Session IV: Post Partum Anestrus.- Post Partum Anestrus, Problems and Perspectives.- Comparative Aspects of the Postpartum Period in Domestic Animals.- Reproductive Potential During the Post Partum Period in Cows.- Endocrine Mechanisms Contributing to Post Partum Anestrus in Dairy and Beef Cattle.- Studies on the Endocrine and Environmental Factors Influencing Post Partum Acyclicity in Dairy Cows Based on Progesterone Profiles.- Discussion.- General Conclusions.- General Conclusions.- List of Participants.