Land / Robinson Genetics of Reproduction in Sheep

1. Auflage 2013
ISBN: 978-1-4831-6173-0
Verlag: Elsevier Science & Techn.
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 440 Seiten, Web PDF

Genetics of Reproduction in Sheep is a compilation of papers that are concerned with the study and application of genetics to the reproduction in sheep. The book is divided into six parts, grouping the papers according to topic. The main topics include genetic variation and selection; the inheritance and the effects of the Booroola gene; genetic strategies for single genes; physiology of genetic variation; the physiological criteria of genetic merit; and the national requirement and systems of husbandry. The text is recommended for those involved with raising sheep and plan to apply genetics in their reproduction, as well as for geneticists who wish to conduct studies on how their field is applied to sheep reproduction.

Autoren/Hrsg.

Land, R. B.

Robinson, D. W.

Inhaltsverzeichnis

1;Front Cover;1
2;Genetics of Reproduction in Sheep;4
3;Copyright Page;5
4;Table of Contents;8
5;Preface;6
6;Part I: Genetic variation and selection;14
6.1;Chapter 1. Selection for litter size;16
6.1.1;Introduction;16
6.1.2;Desired levels of prolificacy;16
6.1.3;Methods of effecting genetic change in litter size in sheep;20
6.1.4;Potential rates of improvement from selection for litter size;21
6.1.5;Results of selection for prolificacy in sheep;22
6.1.6;Possibilities for increasing rates of response to selection for litter size;25
6.1.7;Acknowledgements;30
6.1.8;References;30
6.2;Chapter 2. Crossbreeding for fecundity;32
6.2.1;Introduction;32
6.2.2;Materials and methods;32
6.2.3;Results and discussion;33
6.2.4;References;36
6.3;Chapter 3. Evaluation and utilization of Finn sheep;38
6.3.1;Introduction;38
6.3.2;Breed evaluation;39
6.3.3;Breed utilization;42
6.3.4;Parameter estimation;47
6.3.5;Testis size and ovulation rate;49
6.3.6;Selection for length of breeding season;50
6.3.7;References;51
6.4;Chapter 4. The performance of Romanov crosses and their merits as a basis for selection;52
6.4.1;Introduction;52
6.4.2;Materials and methods;52
6.4.3;Results;55
6.4.4;Discussion;56
6.4.5;References;58
6.5;Chapter 5. Genetic studies of reproduction in Norwegian sheep;60
6.5.1;Introduction;60
6.5.2;Breeds and their fecundity;60
6.5.3;Genetic and phenotypic parameters;61
6.5.4;Selection experiments;63
6.5.5;Realized genetic gain;64
6.5.6;Utilization of Finn sheep;65
6.5.7;References;66
6.6;Chapter 6. Crossbreeding for fecundity in subtropical sheep;68
6.6.1;Introduction;68
6.6.2;Oestrus activity and postpartum interval of subtropical sheep;68
6.6.3;Crossbreeding trials for improving fecundity of subtropical sheep;71
6.6.4;Conclusions;74
6.6.5;Acknowledgements;74
6.6.6;References;74
6.7;Chapter 7. The fecundity of the Chios sheep;76
6.7.1;Introduction;76
6.7.2;Materials and methods;76
6.7.3;Results and discussion;77
6.7.4;Acknowledgements;80
6.7.5;References;80
6.8;Chapter 8. Prolific breeds of goat;82
6.8.1;Introduction;82
6.8.2;Prolific breeds;82
6.8.3;Factors affecting litter size;87
6.8.4;Meat production;90
6.8.5;Selection for litter size;91
6.8.6;Extending the use of prolific breeds of goats;91
6.8.7;References;92
6.9;Chapter 9. Reproductive physiology in South American Camelids;94
6.9.1;Introduction;94
6.9.2;Reproduction in alpacas;96
6.9.3;Normal morphology of the genital organs in alpacas;96
6.9.4;The reproductive physiology of the alpaca;99
6.9.5;References;107
6.10;Chapter 10. Genetic and maternal effects on sheep reproduction and their influence on selection;110
6.10.1;Introduction;110
6.10.2;Modelling a complex reproductive character;110
6.10.3;Evidence for non-maternal effects from the literature;112
6.10.4;Covariance of relatives and interpretation of heritability estimates;114
6.10.5;Selection pressure from selection based on information of various relatives;116
6.10.6;References;117
6.11;Chapter 11. Improvement of reproductive performances in Rasa Aragonesa. Present results in selection and crossbreeding experiments;120
6.11.1;Selection scheme;120
6.11.2;Crossbreeding with prolific breeds;121
6.12;Chapter 12. The preliminary results of selection for prolificacy in Polish Merino sheep;124
6.12.1;References;125
7;Part II: The inheritance and effects of the Booroola gene;126
7.1;Chapter 13. The single gene inheritance of the high litter size of the Booroola Merino;128
7.1.1;Introduction;128
7.1.2;The segregation criterion and problems in the segregation analyses;129
7.1.3;Lines of evidence supporting the major gene hypothesis;131
7.1.4;Characteristics of the gene;135
7.1.5;Acknowledgements;138
7.1.6;References;138
7.2;Chapter 14. The productivity of Bungaree, Booroola X Bungaree and Trangie Fertility X Bungaree Merino ewes in South Australia;140
7.2.1;Introduction;140
7.2.2;Materials and methods;140
7.2.3;Results;143
7.2.4;Discussion;145
7.2.5;Conclusions;148
7.2.6;Acknowledgements;149
7.2.7;References;149
7.3;Chapter 15. Introduction and management of the Booroola gene in sheep flocks in New Zealand;152
7.3.1;Introduction;152
7.3.2;Implications of the single gene;152
7.3.3;Identification of carrier animals;153
7.3.4;Breeding systems;154
7.3.5;Distribution of birth rank;156
7.3.6;Lamb birth weight and survival;156
7.3.7;Lamb rearing;157
7.3.8;Reproductive performance of Booroolas in commercial flocks;158
7.3.9;The future Booroola;160
7.3.10;Acknowledgements;161
7.3.11;References;161
8;Part III. Genetic strategies for single genes;162
8.1;Chapter 16. Utilization of major genes;164
8.1.1;Introduction;164
8.1.2;Normal selection;164
8.1.3;Detection;165
8.1.4;Estimation of parameters;165
8.1.5;Economic effects;166
8.1.6;Manipulation;166
8.1.7;Introgression;168
8.1.8;Special developments;169
8.1.9;Discussion;170
8.1.10;References;170
8.2;Chapter 17. Single genes for fecundity in Icelandic sheep;172
8.2.1;Introduction;172
8.2.2;Known effects of single genes on fecundity;172
8.2.3;The sheep in Borgarhoefn County in Iceland;174
8.2.4;Single-gene criterion and segregation tests;174
8.2.5;Heritability estimate, and records of one-year-old ewes;177
8.2.6;Miscellaneous information on the high fecundity condition;177
8.2.7;The high fecundity sheep at Skriduklaustur;178
8.2.8;The utilization of the high fecundity gene;179
8.2.9;Acknowledgement;180
8.2.10;References;180
8.3;Chapter 18. Principles and practice for the use of the Booroola Merino in extensive husbandry;182
8.3.1;Introduction;182
8.3.2;Extensive husbandry;183
8.3.3;Transferring the Booroola fecundity;183
8.3.4;References;186
8.4;Chapter 19. Linear programming model for incorporating the Booroola gene into another breed;188
8.4.1;Methods;188
8.4.2;Results;192
8.4.3;Discussion;193
8.4.4;Reference;194
9;Part IV: Physiology of genetic variation;196
9.1;Chapter 20. Breed differences in ovulation rate and uterine efficiency and their contribution to fecundity;198
9.1.1;Introduction;198
9.1.2;Breed differences in ovulation rate;199
9.1.3;Breed differences in uterine efficiency;200
9.1.4;Ovulation rate and uterine efficiency effects on litter size;203
9.1.5;Acknowledgements;203
9.1.6;References;203
9.2;Chapter 21. Contribution of variation in ovulation rate and embryo survival to within breed variation in litter size;206
9.2.1;Introduction;206
9.2.2;Materials and methods;206
9.2.3;Results;208
9.2.4;Discussion;211
9.2.5;Conclusion;213
9.2.6;Acknowledgements;213
9.2.7;References;213
9.3;Chapter 22. The mechanism of action of genes controlling reproduction;216
9.3.1;Genetic variation in the serum concentration of gonadotrophins and their regulation;219
9.3.2;Genetic variation in ovarian responsiveness to gonadotrophins in selected lines;220
9.3.3;Genetic variation in ovarian responsiveness to gonadotrophins in inbred strains;221
9.3.4;The nature of genetic differences in hCG stimulated cAMP production;225
9.3.5;The effect of H-2 on ovarian responsiveness to gonadotrophins;226
9.3.6;Significance;227
9.3.7;Acknowledgements;228
9.3.8;References;228
9.4;Chapter 23. Reproductive endocrinology of prolific sheep: studies of the Booroola Merino;230
9.4.1;Introduction;230
9.4.2;Reproduction of Booroola and control Merinos;231
9.4.3;Involvement of LH and LH pulse frequency in the ovulatory physiology of prolific sheep;231
9.4.4;Comparisons of plasma FSH concentrations in the oestrous cycle of prolific sheep breeds other than the Booroola Merino;234
9.4.5;Studies of FSH in Booroola and control Merinos;236
9.4.6;Gonadotrophin studies of the Booroola Ram;244
9.4.7;Conclusion;246
9.4.8;Acknowledgements;247
9.4.9;References;247
9.5;Chapter 24. Ovulation rate and oestrus in Booroola genotypes: some effects of age, season and nutrition;250
9.5.1;Introduction;250
9.5.2;Age;250
9.5.3;Season;252
9.5.4;Nutrition;252
9.5.5;Implications for identification of genotypes;253
9.5.6;Oestrus and the pre-ovulatory LH surge;253
9.5.7;Mechanisms resulting in increases in ovulation rate;254
9.5.8;References;255
9.6;Chapter 25. Sexual and ovarian function of the D'man ewe;258
9.6.1;Introduction;258
9.6.2;Materials and methods;261
9.6.3;Results;262
9.6.4;Ovulation and oestrus;266
9.6.5;Embryonic survival;269
9.6.6;Discussion;269
9.6.7;Acknowledgements;273
9.6.8;References;273
9.7;Chapter 26. Folliculogenesis in sheep: control of ovulation rate;274
9.7.1;Introduction;274
9.7.2;Development, maturation and atresia of follicles;274
9.7.3;Comparisons of peripheral concentrations of hormones between breeds of sheep;278
9.7.4;The mature follicle population throughout the reproductive cycle in different sheep breeds;280
9.7.5;Manipulation of the ovulation rate;283
9.7.6;Conclusions;285
9.7.7;References;285
9.8;Chapter 27. Physiological criteria for embryo mortality: is asynchrony between embryo and ewe a significant factor?;288
9.8.1;Introduction;288
9.8.2;The extent of prenatal loss;288
9.8.3;Mechanism causing embryo loss: a unifying hypothesis;289
9.8.4;The physiology of early pregnancy;289
9.8.5;Sources of variation that could lead to asynchrony;293
9.8.6;How do environmental factors influence embryo survival?;295
9.8.7;Implications of the hypothesis;299
9.8.8;References;300
9.9;Chapter 28. Physiological criteria in genetic selection for aseasonality;304
9.9.1;Introduction;304
9.9.2;The hormonal control of reproduction;305
9.9.3;Physiological criteria for use in genetic selection programmes;311
9.9.4;Conclusion;312
9.9.5;References;312
9.10;Chapter 29. Parameters of male fertility and their genetic variation in sheep;314
9.10.1;Definitions of parameters;314
9.10.2;Genetic variation;318
9.10.3;Male genital tract and sperm production;321
9.10.4;Conclusions;325
9.10.5;Acknowledgements;325
9.10.6;References;325
9.11;Chapter 30. FSH plasma levels in male and female lambs issued from Lacaune rams with high or low prolificacy index;328
9.11.1;Reference;328
10;Part V: Physiological criteria of genetic merit;330
10.1;Chapter 31. Detection and genetic assessment of physiological criteria of merit within breeds;332
10.1.1;Introduction;332
10.1.2;Objectives;332
10.1.3;Estimates of parameters;335
10.1.4;Experimental designs;337
10.1.5;Use of selection;340
10.1.6;Concluding remarks;343
10.1.7;References;344
10.2;Chapter 32. Testis size and LH response to LH-RH as male criteria of female reproductive performance;346
10.2.1;Introduction;346
10.2.2;Selection for testis size;346
10.2.3;Selection for the LH response to LH-RH;351
10.2.4;Discussion;352
10.2.5;References;354
10.3;Chapter 33. Heritabilities of testis size and sexual behaviour in males and their genetic correlations with measures of female reproduction;356
10.3.1;Introduction;356
10.3.2;Experimental data;357
10.3.3;Acknowledgements;358
10.3.4;References;358
11;Part VI: Nutritional requirements and systems of husbandry;360
11.1;Chapter 34. Protein, energy and ovulation rate;362
11.1.1;Composition of feedstuffs;363
11.1.2;How does nutrition affect ovulation rate?;364
11.1.3;Role of protein and energy on ovulation rates;364
11.1.4;Conclusions;371
11.1.5;Acknowledgements;371
11.1.6;References;371
11.2;Chapter 35. Nutritional requirements of the pregnant and lactating ewe;374
11.2.1;Feeding strategy for the first 90 days of pregnancy;374
11.2.2;Energy and protein needs for maintenance;375
11.2.3;Net rates of accretion of nutrients in late pregnancy;376
11.2.4;Nutrient requirements in late pregnancy;377
11.2.5;Nutrient requirements for lactation;380
11.2.6;Effects of failing to meet energy needs in late pregnancy and lactation;382
11.2.7;References;382
11.3;Chapter 36. The possibilities for improving the performance of ewes suckling three or more lambs in grazing systems;384
11.3.1;Results of rearing multiple lambs at pasture;384
11.3.2;Effects of birth weight on growth of lambs;386
11.3.3;Relationship of milk and solid food intake;386
11.3.4;Milk yield of ewes suckling multiples;387
11.3.5;Voluntary food intake by ewes;389
11.3.6;Methods of improving growth of multiple lambs at pasture;390
11.3.7;Conclusion;393
11.3.8;References;393
11.4;Chapter 37. The utilization of Romanov sheep in a system of integrated husbandry;396
11.4.1;Introduction;396
11.4.2;Materials and methods;396
11.4.3;Results and discussion;397
11.4.4;Conclusions;401
11.4.5;References;402
11.5;Chapter 38. Productivity of Booroola cross Merinos inWestern Australia;404
11.5.1;Introduction;404
11.5.2;Materials and method;404
11.5.3;Results;406
11.5.4;Discussion;410
11.5.5;Acknowledgements;411
11.5.6;References;411
11.6;Chapter 39. Intensive husbandry of fecund sheep;412
11.6.1;Introduction;412
11.6.2;General description of the research programme;412
11.6.3;Genetics research;414
11.6.4;Nutrition research;416
11.6.5;Reproductive physiology research;418
11.6.6;Potential for adoption of new technology and management strategies to maximize production capability of sheep;420
11.6.7;References;420
12;Index;424