May 14, 2009

An Introduction to Practical Animal Breeding - Background and contents - 2009

Agriculture, farming, animal production, animal breeding, genetics, livestock improvement, basic biology, Mendelism, genetic theory, population genetics, practical application of theory, breeding, selection decisions, breeding methods, breeding practice, breeds, breed structure, cattle, sheep, pigs, poultry, New Zealand).

An Introduction to Practical Animal Breeding

By D. C. Dalton (1980)

ISBN 0-246-11194-1 Hardback
ISBN 0-246-11351-0 Paperback

2009 Background comments to book
As a student in the early 1950s at King’s College, University of Durham in Newcastle upon Tyne in UK, I developed a great interest in animal breeding. Those were the days of text books which we students revered, and they were relevant for decades.

I also worshipped my Kiwi Prof, M.M (Mac) Cooper who did more for practical animal breeding in UK than anyone before or since. After my PhD in sheep breeding in North Wales, I went on to teach animal production at Leeds University and do breeding research with laboratory mice. Farm animals were not available which had many advantages in terms of quick turnover of generations.

So by this stage I had seen every textbook on the subject and had ‘tried’ to read them all. They would have made a stack about a metre high and the vast majority of them although editorial masterpieces were terrible to read.

They all started off saying the book was designed for students, and some would even add farmers to the intended audience. All went well for the first chapter or maybe two, until you hit Mendel and his peas.

Then soon after this, you hit algebra and calculus, and that was the end for most folk who were desperate to know what to do after you had the sheep into the pens, or the cows in the yard. Then what?

How did you sort out the best ones for breeding and the worst for culling? Students rarely got to this point, and even if they did, they were so switched off by Mendel and algebra that they gave it all away.

Lecturers killed animal breeding for most students. Having suffered the pain of listening to hours of this as a student, and being very conscious of the pain I inflicted on my students when covering the syllabus to get them to pass exams, frustration motivated me to try to keep things simple.

When I moved into animal breeding research in New Zealand, I really enjoyed the relief of not having to bore students to death any more with genetics and animal breeding. It was over- so I thought.

Then as our research developed, we had regular groups of farmers and university students coming to the research station to see what was going on, and asking not just the ‘what’ questions, but the more important ‘why’ ones too.

We initiated large scale breeding schemes with 280,000 sheep and 16,000 beef cattle where the staff involved wanted to know the background theory to the programmes.

So I was back in the business of explaining genetics and animal breeding all over again -but this time, the ‘students’ couldn’t get enough of the subject, and drove us to exhaustion with their searching questions. It was an incredibly rewarding time.

So this book really came from those years. It was written in 1980 and a lot has changed since them in the high-tech end of genetics, and with computers having so much more power to analyse massive amounts of field data. But not much has changed down at the sheep and cattle yards where we are still looking for the best stock, and deciding what to mate them to, to bring about improvement. The book became a recognised text book in English speaking countries and was translated into Japanese and Spanish.

When my first and second edition ran out, Malcolm Willis from Newcastle University in UK produced a third edition in 1991 under the title of ‘Dalton’s Introduction to Practical Animal Breeding’. Publisher: Blackwell Scientific Publications. ISBN 0-632-03126-3.

Book Contents Foreword


Acknowledgements Part I The Traits in Farm Animals Man and his animals Traits: a general comment Reproduction - Birth traits and survival - Maternal ability - Lactation Growth and development The carcass – Wool production - Draught and speed – Physical features - Learning ability - Temperament - Poultry meat and egg production Summary Part II Basic Biology and Mendelism Basic biology Body cells and germ cells - Chromosomes and sex - Changes in the number of chromosomes - Changes within one chromosome. Mendel's genetics: Mendelism Technical language of Mendelism The naming of genes Mendel's mathematics and more terminology Mendel's ratios – Lethal genes - Linkage and crossing over - Sex linkage - Chromosome mapping - Mutations How many genes concern breeders? The action of the genes: how they work - Pleiotropy – Gene interaction - Different types of dominance - Epistasis Heredity and environment Part III Population Genetics, Selection and Breeding The complexity of traits in farm animals The bridge between Mendelism and population genetics Population genetics: variation Variation: how to describe it? - Other shaped curves – The challenge: to improve the mean - Where to start? – Comparison between populations Selection Artificial and natural selection - Culling Genetic progress: what controls it? Heritability - Selection differential- Generation interval -Genetic gain Measuring genetic improvement Controls - Repeat matings Selection limits Preservation of genetic variation Breeding value and aids to selection Individual or mass selection (performance testing) – Lifetime performance records - Pedigree information – Progeny performance (progeny testing) - Performance of other relatives (family selection) - Combination of selection aids – Selection methods - Relationships between traits - Traditional relationships between traits - Different types of correlations Breeding and the environment Maternal environment Breeding methods Inbreeding - Outbreeding - Crossbreeding - What to do afer the first cross (F1) - Outcrossing - Backcrossing - Top crossing and grading up - Mating likes - Mating unlikes Hybrids and heterosis Hybrid vigour in farm livestock - Combining ability: general and specific Part IV Breeding in Practice Practical breeding plans Identification - Dairy cattle breeding - Beef cattle breeding - Dual-purpose cattle breeding - Sheep breeding - Dual-purpose sheep breeding - Pig breeding - Poultry breeding Breeds and breed structure Breed associations - Livestock shows -Co-operative breeding schemes - Artificial insemination and ovum transfer - Tests and trials - Randomisation - Pre-test environmental problems - Correction factors - Costs and benefits of genetic improvement References Appendix I The coefficient of inbreeding Appendix I1 Random numbers Glossary

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