Population Genetics & Animal Breeding Lesson 1 Introduction to 311

Aims and objectives This module aims to provide an understanding of the principles and practices of animal breeding and genetic improvement to enhance animal productivity. It will give particular emphasis on animal breeding in the Bhutanese context.

Introduction to Population Genetics Livestock plays a central role in the overall Bhutanese agriculture production system. One of the main constraints to increasing animal productivity in Bhutan is the breed with low genetic potentials for high performance. In view of this, one of the main interventions in the livestock sector is to improve the breed through grading up of the native animal with exotic high yielding breeds. This module has 16 main topics which deals with the theory and practice of animal breeding and breed improvement for increased animal productivity.

Why is the module so important? Understand the principles of population genetics Understand how the Quantitative traits are inherited Analyze the importance and causes of variation Analyze the principles of regression and correlation between traits Estimate heritability and repeatability of economic traits Describe the traits of economic importance in livestock species Describe the heritability and repeatability of various economic traits and their correlation Carry out the selection of animal for breeding based on different selection methods and tools

Why is the subject so important? State the importance of breeding in Animal Production Explain inbreeding and its effects Analyze the importance of crossbreeding and grading up Describe the animal breed structure and various breeding schemes Evaluate the national livestock breeding policy Analyze the constraints in animal breeding and production in the country Formulate breeding plans in different agro-ecological zones Explain the importance of conservation of animal genetic resources Search, retrieve, evaluate and synthesize information related to animal breeding

Module content Unit 1. Quantitative genetics, Population genetics, Gene and gene frequency Hardy-Weinberg Law, Factors affecting gene frequency and composition of population Unit 2. Quantitative traits and their inheritance Unit 3. Variation, Nature and causes of variation in quantitative traits Measures of central tendency and dispersion of quantitative traits Regression and correlation Unit 4. Regression and correlation between traits Unit 5. Heritability and repeatability and methods for their estimation Traits of economic importance in farm animals. Genetic correlation among economic traits, their heritability and repeatability values

Module content Unit 6. Origin and domestication of farm animals, consequences of domestication Breeds of livestock and their development, Breeds of livestock and their development Unit 7. Selection- Natural and artificial selection, Methods of selection- Tandem, independent culling level and selection index Calculation of breeding values Selection tools-Mass selection, Selection based on lifetime performance records, pedigree selection, progeny testing, family selection Unit 8. Genetic effects of selection, methods of estimating genetic gain Selection intensity, Generation interval Unit 9. Inbreeding, coefficient of relationship or inbreeding, inbreeding and its effect , Line breeding and development of inbred lines Unit 10. Outbreeding- outcrossing, crossbreeding, grading-up, heteriosis and complementarity

Module content Unit 11. Animal Breeding structures and schemes- Closed nucleus breeding, open nucleus breeding Unit 12. Animal breeding systems in the country Opportunities for breeding and improvement of farm animals in Bhutan National Breeding Policy Constraints in breeding and improvement of livestock productivity under various systems Unit 13. Breeding plans for improvement of farm animals in different agro-ecological zones of Bhutan Unit 14. Conservation of animal genetic resources Unit 15. Seminar on different topics related to animal breeding

Teaching and Learning The module involves: 43 hours of classroom lecture, 24 hours of practical, 24 hours assignment and 29 hours of self study

Assessment Assessment Weighting Continuous assessment (60%) Written tests 30 Assignment 20 Practical Exam 10 Final assessment (40%) Written Exam 30

References Essential Reading: Willis, M. B. 1991. Dalton’s Introduction to Practical Animal Breeding. 3rd Edn. Blackwell Scientific Publications, Oxford Falconer, D.S. and Mackay, T.F.C. 1996. Introduction to Quantitative Genetics. 4th edn. Longman, Harlow Simm, G. 1998. Genetic Improvement of Cattle and Sheep. Farming Press, Tonbridge

References Additional Reading: http://anthro.palomar.edu/mendel/mendel_1.htm http://www.ndsu.edu/instruct/mcclean/plsc431/mendel/mendel1.htm http://www.netpets.com/dogs/reference/genetics/inbreeda.html http://extension.missouri.edu/explore/agguides/ansci/g02910.htm