Genetic improvement of cattle and sheep / Geoff Simm.

Enhanced descriptions from Syndetics:

Humans started domesticating farm livestock over 10,000 years ago. For much of this time, livestock have been changed genetically by subjective means. In the past 50 years, the application of scientific methods to animal breeding has led to major improvements in the output, cost and quality of animal products in the last few decades. This book describes the principles of genetic improvement of farm livestock and the practical application of these principles to dairy cattle, beef cattle and sheep breeding. Originally published in 1998 by Farming Press.

Table of contents provided by Syndetics

• Foreword (p. viii)
• Preface (p. ix)
• Acknowledgements (p. xi)
• Chapter 1. The origins of today's livestock breeds (p. 1)
• Natural selection and evolution (p. 1)
• Domestication (p. 2)
• Origins of livestock breeds (p. 4)
• Summary (p. 5)
• Chapter 2. Genes, genetic codes and genetic variation (p. 7)
• Introduction (p. 7)
• Chromosomes and genes (p. 8)
• The structure and function of genes (p. 11)
• DNA and genetic codes (p. 11)
• Loci and alleles (p. 13)
• Transfer of genetic codes during cell division (p. 14)
• Mitosis (p. 15)
• Meiosis (p. 16)
• Mutation (p. 17)
• Tracking genes across generations (p. 19)
• Genes, genotypes and phenotypes (p. 19)
• Predicting the outcome of matings between different genotypes (p. 21)
• Genotype and gene frequencies (p. 24)
• Sources of genetic variation between animals (p. 26)
• Types of gene action (p. 28)
• Additive and non-additive gene action (p. 28)
• Co-dominance, no dominance or additive gene action (p. 28)
• Complete dominance (p. 30)
• Partial dominance (p. 33)
• Overdominance (p. 33)
• Other types of gene action and inheritance (p. 33)
• Sex-linked genes (p. 33)
• Sex-limited genes (p. 34)
• Sex-influenced genes (p. 34)
• Genomic imprinting (p. 34)
• Pleiotropy (p. 35)
• Epistasis (p. 35)
• Incomplete penetrance and variable expressivity (p. 36)
• Cytoplasmic or mitochondrial inheritance (p. 36)
• Names of genes and their abbreviations (p. 37)
• The nature of traits of interest in farm animals (p. 38)
• Qualitative and quantitative traits (p. 38)
• Genetic and environmental influences (p. 38)
• Traits affected by single genes (p. 40)
• Traits affected by many genes (p. 41)
• Measuring variation in performance (p. 46)
• Measuring associations between traits and between animals (p. 50)
• Phenotypic, genetic and environmental associations (p. 55)
• Summary (p. 58)
• Chapter 3. Strategies for genetic improvement (p. 64)
• Introduction (p. 64)
• The structure of livestock breeding industries (p. 65)
• Selection between breeds (p. 70)
• Selection within breeds (p. 74)
• Requirements for within-breed selection (p. 76)
• Factors affecting rates of improvement (p. 78)
• Selection for more than one trait (p. 81)
• Crossbreeding (p. 83)
• Reasons for crossing (p. 83)
• Types of heterosis (p. 89)
• Systems of crossing (p. 93)
• Conservation of genetic resources (p. 95)
• Why conserve rare breeds? (p. 95)
• Which breeds should be conserved? (p. 97)
• Methods of conservation (p. 98)
• Summary (p. 100)
• Chapter 4. What affects response to selection within breeds? (p. 107)
• Introduction (p. 107)
• Factors affecting rates of genetic gain (p. 108)
• Selection differential (p. 108)
• Heritability (p. 109)
• Generation interval (p. 112)
• A more useful formula for predicting response (p. 113)
• The link between selection intensity and generation interval (p. 117)
• Using information from relatives (p. 120)
• Accuracy of selection (p. 123)
• Additive genetic standard deviation (p. 124)
• A practical example (p. 126)
• Using repeated records of performance (p. 128)
• Predicting correlated responses to selection (p. 131)
• Limitations of these predictions (p. 132)
• Controlling inbreeding (p. 134)
• Summary (p. 141)
• Chapter 5. Predicting breeding values (p. 148)
• Introduction (p. 148)
• Management of candidates for selection (p. 148)
• Adjusting records of performance (p. 149)
• Additive correction factors (p. 149)
• Multiplicative correction factors (p. 151)
• Standardising to adjust records (p. 151)
• Predicting breeding values (p. 153)
• Clues to an animal's breeding value (p. 153)
• Calculating PBVs (p. 153)
• Using the animal's own performance (p. 153)
• Using information from relatives (p. 155)
• Selection indexes (p. 158)
• Combining information on a single trait from relatives (p. 159)
• Combining information on different traits (p. 160)
• A practical example (p. 163)
• BLUP (p. 165)
• How BLUP works (p. 167)
• BLUP models (p. 171)
• Direct and maternal genetic effects (p. 172)
• Single and multi-trait BLUP (p. 174)
• Benefits of BLUP (p. 175)
• Using economic values with BLUP (p. 176)
• Getting estimates of heritabilities and correlations (p. 177)
• Scale of presentation of genetic merit (p. 178)
• Accuracies and reliabilities (p. 179)
• International conversions and evaluations (p. 183)
• International conversions (p. 183)
• Factors affecting feasibility and reliability (p. 183)
• An example (p. 185)
• International evaluations (p. 186)
• Summary (p. 188)
• Chapter 6. Dairy cattle breeding (p. 196)
• Introduction (p. 196)
• Breeding goals (p. 197)
• Breeds and crosses used in dairying (p. 203)
• Selection within breeds (p. 206)
• Systems of testing (p. 206)
• Progeny testing schemes (p. 206)
• How progeny testing works (p. 206)
• Pathways of genetic improvement with progeny testing (p. 210)
• Pros and cons of progeny testing (p. 210)
• Nucleus breeding schemes (p. 211)
• Theoretical benefits (p. 211)
• MOET schemes in practice (p. 214)
• Do MOET nucleus schemes work? (p. 216)
• Traits recorded (p. 217)
• Milk recording (p. 217)
• Type traits (p. 219)
• Reproduction, health and workability (p. 222)
• Feed intake, live weight and body condition (p. 225)
• Methods and results of genetic evaluation (p. 226)
• Milk production traits (p. 226)
• Other traits (p. 231)
• Indexes of overall economic merit (p. 233)
• Evidence of genetic improvement and its value (p. 237)
• Genotype x environment interactions (p. 240)
• Practical guidelines on selection (p. 242)
• Summary (p. 244)
• Chapter 7. Beef cattle breeding (p. 253)
• Introduction (p. 253)
• Breeding goals (p. 255)
• Beef breeding goals in dairy and dual-purpose breeds (p. 255)
• Terminal sires for use in dairy herds and specialised beef herds (p. 256)
• Breeding replacement females for specialised beef herds (p. 259)
• Breeds and crosses used in beef production (p. 261)
• Selection within breeds (p. 264)
• Systems of testing (p. 264)
• Performance testing (p. 264)
• Progeny testing (p. 266)
• Cooperative breeding schemes (p. 267)
• MOET nucleus schemes (p. 268)
• Traits recorded (p. 268)
• Methods and results of genetic evaluation (p. 273)
• Overview (p. 273)
• Steps involved in genetic evaluation (p. 275)
• Evaluations across herds, breeds and countries (p. 283)
• Indexes of overall economic merit (p. 284)
• Evidence of genetic improvement and its value (p. 286)
• Estimates of genetic change (p. 286)
• Value of genetic improvement (p. 288)
• Genotype x environment interactions (p. 289)
• Practical guidelines on selection (p. 289)
• Selection between breeds or crosses (p. 290)
• Selection of bulls (or semen) for use in a purebred herd (p. 290)
• Selection of replacement females in a purebred herd (p. 291)
• Selection of replacement bulls and cows for a commercial herd (p. 292)
• Summary (p. 292)
• Chapter 8. Sheep breeding (p. 300)
• Introduction (p. 300)
• Breeding goals (p. 302)
• Meat production (p. 302)
• Wool production (p. 306)
• Milk production (p. 308)
• Multi-purpose breeding goals (p. 309)
• Breeds and crosses used in sheep production (p. 310)
• Meat production (p. 310)
• Wool production (p. 312)
• Dual-purpose meat and wool production (p. 313)
• Milk production (p. 314)
• Selection within breeds (p. 314)
• Meat production (p. 314)
• Systems of testing (p. 314)
• Traits recorded (p. 318)
• Methods and results of genetic evaluation (p. 322)
• Use of indexes of overall economic merit (p. 324)
• Evidence of genetic improvement and its value (p. 328)
• Wool production (p. 332)
• Systems of testing (p. 332)
• Traits recorded (p. 333)
• Methods of genetic evaluation (p. 335)
• Use of indexes of overall economic merit (p. 335)
• Evidence of genetic improvement and its value (p. 335)
• Milk production (p. 336)
• Genotype x environment interactions (p. 337)
• Practical guidelines on selection (p. 337)
• Selection between breeds or crosses (p. 338)
• Selection of rams (or semen) for use in a purebred flock (p. 338)
• Selection of replacement females in a purebred flock (p. 339)
• Selection of replacement rams and ewes for a commercial flock (p. 340)
• Summary (p. 340)
• Chapter 9. New technologies (p. 347)
• Introduction (p. 347)
• Reproductive technologies (p. 348)
• Artificial insemination (p. 349)
• Multiple ovulation and embryo transfer (p. 350)
• In vitro production of embryos (p. 352)
• Semen and embryo sexing (p. 354)
• Embryo cloning (p. 355)
• Molecular genetic technologies (p. 358)
• Developments in molecular and cell biology (p. 359)
• Genome mapping (p. 364)
• Types of genome map (p. 365)
• Linkage maps (p. 365)
• Physical maps (p. 367)
• Creating a consensus map (p. 371)
• Status of livestock genome maps (p. 371)
• Use of molecular markers in selection (p. 372)
• Choice of markers (p. 373)
• Establishing a link between a marker and a trait of interest (p. 375)
• An example of marker assisted introgression (p. 378)
• An example of marker assisted selection (p. 381)
• Gene transfer (p. 382)
• Ethical implications of new technologies (p. 385)
• Summary (p. 390)
• Table showing values of selection intensity for different proportions of animals selected (p. 400)
• Glossary of technical terms (p. 404)

Author notes provided by Syndetics