Studies on Prostaglandin Control of Practical Bovine Reproduction

This thesis consists of a series of 12 Papers which are related as investigating exogenous hormonal control of bovine reproduction under practical agricultural conditions. In particular the objective was to produce additional information on the use of prostaglandin F2alpha. The methods and techniques which were used take account of the special requirements and restrictions of typical commercial husbandry conditions In PART 1, the need for detection of bovine oestrus as a necessary preliminary to artificial insemination is discussed. This has been identified as a factor responsible for unsatisfactory conception rates. The physiological principles, practical problems, and economic consequences of these difficulties are examined in detail. Methods of improving the effectiveness of oestrus detection, and their limitations, are discussed. The endogenous hormonal control mechanisms of the bovine oestrous cycle are examined in detail with particular regard to how they may be manipulated by administration of exogenous hormones. The development of techniques to control oestrus and ovulation by administration of different hormones is discussed. Detailed discussion of the principles involved, techniques required, and difficulties encountered are illustrated by reference to development trials for a progestagen-implant technique. The principles involved and techniques which were used, are related to bovine oestrous cycle control with prostaglandin F2alpha. (Abstract shortened by ProQuest.)