Proceedings of a final research co-ordination meeting organized by the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Bogotá, 19–23 September 1988. The general goals of this programme, which was part of the ARCAL (Arreglos Regionales Cooperativos para la Promoción de la Ciencia y la Tecnología Nucleares en América Latina) project, were to characterize and improve the reproductive management of milk, meat and fibre producing livestock maintained under the diverse environmental and management conditions prevailing in the Latin American region. In particular, the programme addressed the efficacy of using radioimmunoassay methods to measure reproductive performance on the basis of breeding and production records, behaviour and clinical parameters. Contents: Part I: Milk production systems; Part I(a). Intensive dairying systems; Part I(b). Dual purpose systems; Part II. Beef production systems; Part III: Sheep and goat production systems; Part IV: Camelids.