CONTENTS
CHAPTER 5 REPRODUCTION 1: FACTORS AFFECTING FERTILITY AND FECUNDITY 111 Kym A Abbott
5.1 Introduction 111 5.1.1 The Role of Reproduction in the Productivity of Sheep
Grazing Systems 111
5.1.2 The Major FactorsInfluencingReproductive Rate 111 5.1.3 The Components ofReproductive Rate 112 5.1.4 Fertility, Fecundity and Survival Rate of Lambs to Marking Age 112
5.2 Physiological and Management Factors Affecting Fertility and Fecundity In the Ewe 113
5.2.1 Photoperiodicity in the Ewe 113
5.2.2 Effects of Body Weight and Nutrition on Ewe Fertility and Ovulation Rate 116
5.2.3 Flushing Ewes 117 5.2.4 Effect of Ewe Age on Fertility andOvulation Rate 118 5.2.5 Ovulation without Oestrus 118 5.2.6 Failure of Fertilisation Due to MaternalFactors 118 5.2.7 Management of Ewes at Joining 118
5.3 Abnormalities and Diseases Affecting Ewe Fertility 119 5.3.1 Phyto-Oestrogenic Infertility 119 5.3.2 Embryo Mortality 120
5.4 |
Factors Affecting the Fertility of Rams Used for Natural Joining |
122 |
5.4.1 |
Photoperiodicity in the Ram |
|
122 |
5.4.2 |
Body Weight, Nutrition and Fertility in the |
Ram |
123 |
5.4.3 |
Puberty and Age Effects in Rams |
|
126 |
5.4.4 |
The Age Structure of the Ram Flock |
|
12 / |
5.4.5 |
Husbandry Procedures and Ram Fertility |
|
127 |
5.4.6 |
Management of Rams at Joining |
|
12 ยง |
5.4.7 |
Failure of Fertilisation Due to an InadequateNumber of Rams |
130 |
5.4.8 |
Failure of Fertilisation Due to Other Ram Factors |
131 |
5.5 Abnormalities and Diseases Affecting Ram Fertility 131
5.5.1 Epididymitis Caused by Brucella ovis Infection( Ovine Brucellosis, OB)
5.5.2 Other Causes of Epididymitis 5.5.3 Non-Specific Abnormalities of the Epididymis 5.5.4 Testicular Abnormalities
5.5.5 Other Abnormalities Detected on Scrotal Palpation 5.5.6 Other Lesions of the Male Genitalia
134 135 136