Proceedings of a seminar and an Advisory Group meeting, Ankara, 3–8 June 1985. Although emphasis is given to the use of immunoassay methods (RIA and EIA) for assessing reproductive status and diagnosing infections, the publication also covers the use of radiation for vaccine production and radioisotopes for measuring water and mineral requirements, and various aspects of digestion and metabolism in ruminant livestock. Contents: Recommendations of the FAO/IAEA Advisory Group meeting on Improving the Productivity of Indigenous Animals in Harsh Environments with the Aid of Nuclear Techniques; Selected contributions from the seminar for developing countries in Africa and the Middle East on Research Using Techniques Aimed at Improving Meat, Milk and Wool Production from Ruminant Animals.