- - AGRICULTURE CORE CURRICULUM - - (CLF3000) Advanced Core Cluster: ANIMAL SCIENCE (CLF3250) Unit Title: LIVESTOCK BREEDING AND GENETICS UNIT DIRECTORY: ___________________________________________________________________________ Code Topic Title Hours Year(s) ___________________________________________________________________________ (CLF3251) Sperm and Egg Production 2 3 / 4 (CLF3252) Review from Basic Core 1 3 / 4 (CLF3253) Dominant and Recessive Genes 3 3 / 4 (CLF3254) Breeding Systems and Situations 2 3 / 4 (CLF3255) Selection and Heritability 1 3 / 4 (CLF3256) Embryo Transfer 1 3 / 4 (CLF3257) Artificial Insemination 2 3 / 4 (CLF3258) Estrous Cycles and Breeding Capacities 2 3 / 4 (CLF3259) Gestation and Parturition 3 3 / 4 (CLF3260) Environment and Care of Reproducing Animals 4 3 / 4 (CLF3261) Feeding Reproducing Animals 2 3 / 4 (CLF3262) Crossbreed Identification 1 3 / 4 (CLF3299) Unit Exam 1 3 / 4 TOTAL TIME FOR UNIT = 25 ____________________________________________________________________________ UNIT GOAL: Students will understand the principles of livestock breeding and Mendelian genetics, and the importance of heritability in a breeding program. ____________________________________________________________________________ ____________________________________________________________________________ UNIT OBJECTIVES: Upon completion of this unit, students will be able to: 1. Briefly define the chromosome theory of inheritance. 2. Draw and describe the difference between oogenesis and spermatogenesis. 3. Review (from the Basic Core, #250) and define the terms: phenotype, genotype, gene, locus, allele, homozygous, heterozygous, variation, and mutation. 4. Diagram the phenotypic and genotypic results of a cross, using traits common to modern livestock, which exhibit classic dominant and recessive characteristics. 5. Diagram a dihybrid cross (e.g. using two heterozygous gene pairs), and determine the genotypes of the offspring. 6. Identify an advantage and a disadvantage of the following breeding systems and give a situation when each could be used: inbreeding, linebreeding, closebreeding, outcrossing, and crossbreeding. 7. Define hybrid using the cross between a horse and a donkey as an example and explain the genetic effects that make the offspring sterile. 8. Describe the genetic factors that influence the sex of an offspring. 9. Define prepotency as it relates to genetics and name a famous sire that possessed these characteristics. 10. Define heritability and explain why selection is important in the livestock industry. 11. Describe a surgical and a nonsurgical method of embryo transfer and explain the impact that embryo transfer has made on the animal genetics industry. 12. List important factors to consider in a bull fertility test. 13. Explain the process of artificial insemination and its impact on the gene pool in modern livestock. 14. List three methods to detect estrus in livestock, explain the importance of detection in a breeding program, and describe the equipment used to detect estrus. 15. List the three stages of parturition, explain when each stage begins and ends, describe the proper fetus presentation, and list possible problems that may occur during delivery. 16. Verbally outline the development of a prenatal farm animal from fertilization to birth using slides. 17. Compare and contrast the estrous cycles of the mare, cow, sow, ewe, and doe rabbit and include the seasons of the year in which they cycle. 18. List the gestation periods of the mare, cow, sow, ewe, and doe rabbit. 19. Define the term freemartin and identify the problems that can occur with freemartins in bovine breeding programs (genetic level). 20. Describe the proper environment for the female during gestation, parturition, and lactation. 21. Describe the proper maintenance and care of male breeding stock. 22. Identify the recommended breeding age for the bull, stallion, buck, boar, and ram and the potential amount of service (years) for breeding males of each species. 23. Develop a feeding regime for a dam through gestation, parturition, and lactation. 24. Perform the appropriate husbandry practices when handling newborn animals. 25. Visually identify cross-breeds of commercial livestock and explain the advantages of the cross. ____________________________________________________________________________ REFERENCES: AMERICAN BREEDERS SERVICE A.I. MANAGEMENT MANUAL. (1983). Wisconsin: W.R. Grace and Co. Ayala, Francisco, and Kiger, John A. (1980). MODERN GENETICS. Menlo Park, CA: Benjamin/Cummings Publishing Co. Bath, Donald L. (1978). DAIRY CATTLE: PRINCIPLES, PRACTICES, PROBLEMS, PROFITS (2nd ed.). Philadelphia: Lea and Febiger. Bundy and Diggins, (1968). LIVESTOCK AND POULTRY PRODUCTION (3rd ed.). Englewood Cliffs: Prentice-Hall Inc. California Vocational Agriculture Curriculum Guidelines, ANIMAL PRODUCTION, "Livestock Breeding and Genetics", Vol.1. Ensminger, M.E. (1983). THE STOCKMAN'S HANDBOOK (6th ed.). Danville, IL: The Interstate Printers and Publishers, Inc. Hafez, E.S. (1974). REPRODUCTION IN FARM ANIMALS (3rd ed.). Philadelphia: Lea and Febiger. Roediger, Roger D. (1977). LIVESTOCK BREEDING. Columbus, Ohio: Agriculture Education Curriculum. Ronning, Magnar, and Cole, H.H. (1974). ANIMAL AGRICULTURE, San Francisco: W.H. Freeman and Co., (Cole and Garrett, later ed.). VanVleck, L.D., Pollak, E.J., and Oltenacu, E.A.B. GENETICS FOR THE ANIMAL SCIENCES. ____________________________________________________________________________ RESOURCES: VEP audio-visual material, "Beef Production Systems, "Beef Selection Kit", "The Reproduction Kit", "Equine A.I.", "Beef Reproduction", "Swine Reproduction Series", and "Basic Genetics". 5/2/90sg #%&C