CONTENTS
CHAPTER8
REPRODUCTION 4: INVESTIG ATIONS OF POOR REPRODUCTIVE RATE IN COMMERCIAL SHEEP FLOCKS 187 Tristan Jubb
8.1 Provision of Veterinary Advice about Reproductive Rate in Ewe Flocks 187 8.1.1 When Will Sheep Producers Seek Veterinary Advice? 187 8.1.2 What Constitutes a Poor Reproductive Rate? 187
8.2 Conducting an Investigation of Poor Reproductive Rates 189 8.2.1 A Conceptual Framework for Investigation 189 8.2.2 Collecting the History and Examining Records 190 8.2.3 Analysing and Interpreting Pregnancy Scanning Data 193 8.2.4 Examination of Ewes Soon after Scanning 194 8.2.5 Analysing and Interpreting Lamb Marking Data 195
8.2.6 Examination of the Ewes and Their Lambs Soon after Lamb Marking 196
8.2.7 Diagnostic Tools 197 References 200
CHAPTER9 REPRODUCTION 5: CONTROLLED BREEDING 201 Simon de Graaf
9.1 Control of Oestrus and Ovulation 201 9.1.1 Synchronisation of Oestrus 201 9.1.2 Advancing the Breeding Season 202
9.1.3 Oestrus Stimulation in Ewes in Postpartum or Lactational Anoestrus 205
9.1.4 Increasing Fecundity 205 9.2 Induction of Abortion 206 9.3 Induction of Parturition 206 9.4 Artificial Insemination( Al) 207 9.4.1 Selection and Preparation of Rams 207 9.4.2 Collection of Semen 207 9.4.3 Handling of Semen 208 9.4.4 Evaluation of Semen 208 9.4.5 Dilution of Ram Semen 209 9.4.6 Storage of Ram Semen 210 9.4.7 Detection of Ewes in Oestrus 210 9.4.8 Insemination of the Ewe 210
9.5 Multiple Ovulation and Embryo Transfer( MOET) 212 9.5.1 Superovulation in Donor Ewes 212