1. Animal Genetics

2. Natural Selection n an organisms ability to SURVIVE and pass on its GENETIC information to its offspring.

3. Artificial Selection n HUMAN control over organisms passing on their GENETIC information.

4. Heredity n the POTENTIAL an organism has to show certain TRAITS due to its GENETIC information

5. Environment n the EXTERNAL conditions that affect the traits and PERFORMANCE of an animal

6. Environment vs. Heredity n An organism's traits and performance are a sum total of its ENVIRONMENT acting upon its GENETIC information.

7. Environment vs. Heredity n Some TRAITS are influenced more by an organism's ENVIRONMENT than by its GENETICS, while others are influenced more by genetics.

8. Heritability n The percentage that a trait is affected by its genetic information is called HERITABILITY. n A heritability factor of 0.0 means that a trait is influenced very little by genetic information n A heritability factor of 1.0 means that a trait is influenced very little by the environment.

9. Examples of Heritability n Birth Weight =.40 n Weaning Weight =.30 n Multiple Births = 0.0 - 0.10 n Dressing Percentage =.60

10. Adaptability n The ability of a BREED to become SUITABLE to specific environmental conditions

11. Type n a group of ANIMALS that are grouped together according to the PRODUCTS they produce n Examples -- Beef type cattle, Dairy type cattle, Wool type sheep, Mutton type sheep

12. Species n a group of ORGANISMS that have several common CHARACTERISTICS that differentiate them from others.

13. Scientific Names of Species n Cattle: Bos taurus, Bos indicus n Sheep: Ovis aires n Swine: Sui suidae n Horse: Euquis caballus n Chickens: Galus galus

14. Breed n animals having a common ORIGIN and CHARACTERISTICS that distinguish them from other groups within the same SPECIES.

15. Purebred n individuals within a BREED. They must have all of the CHARACTERISTICS of the breed and have a recorded PEDIGREE.

16. Pedigree n a record of an individual's ANCESTRY.

17. Breeds of Cattle

18. Angus

20. Hereford

21. Charolais

23. Brahman

25. Shorthorn

27. Simmental

29. Salers

31. Texas Longhorn

32. Red Angus

33. Limousin

34. Belted Galloway

35. Beefmaster

36. Holstein-Friesian

38. Guernsey

39. Jersey

40. Breeds of Sheep

41. Rambouillet

43. Columbia

44. Suffolk

46. Hampshire

47. Merino

48. Dorset

49. Lincoln

50. Breeds of Swine

51. Duroc

52. Hampshire

53. Chesterwhite

54. Yorkshire

55. Landrace

56. Production of Sex Cells (Meiosis) n 1. SIMILAR events to mitosis n 2. Occurs ONLY in the TESTES and OVARIES to produce egg and sperm cells. n 3. REDUCES the NUMBER of chromosomes to half the normal number. n 4. ONE replication followed by TWO cell divisions.

57. Meiosis

58. FERTILIZATION n the union of the egg and sperm nuclei n restores the normal chromosome number.

59. ZYGOTE n a fertilized egg

60. SPERMATOGENESIS n 1. occurs in TESTES n 2. EQUALLY sized cells n 3. FOUR sperm cells produced

61. Spermatogenesis

62. OOGENESIS n 1. occurs in OVARIES n 2. DIFFERENT sized cells n 3. ONE egg cell produced and three POLAR bodies

63. Oogenesis

64. Patterns of Inheritance

65. DOMINANT n the trait that SHOWS in a cross between twotrue-breeding parents n Example in Cattle -- Black coat color, polled n Example in Sheep -- White wool n Example in Swine -- Black hair

66. Recessive n the trait that is HIDDEN in a cross between two individuals. n Example in Cattle -- Red coat color, horns, dwarfism n Example in Sheep -- Black wool n Example in Swine -- Red hair

67. PHENOTYPE n the OUTWARD appearance of the organism

68. Genotype n the actual GENE MAKEUP of an organism

69. Homozygous n when both of the genes (letters) in the pair are the SAME n Example -- TT or tt

70. Heterozygous n when both of the genes (letters) in the pair are DIFFERENT n Example -- Tt

71. Incomplete Dominance n The genes are neither dominant nor recessive, but are equals n Example -- Shorthorn Cattle –WW=White –RR=Red, –RW=Roan

72. Types of Mating Systems n Purebred n Inbreeding n Linebreeding n Outcrossing n Grading up n Crossbreeding

73. Hybrid vigor n increased performance of offspring over that of the parents when unrelated individuals are mated. n Heterosis

74. Performance Pedigrees n summarizes a particular animal's own performance records as well as records of ancestors, siblings, and progeny. n Progeny = offspring

75. EPD n EXPECTED PROGENY DIFFERENCE n an INDICATION of the amount of GENETIC merit that an animal will pass on to its offspring.

76. EPD example n a bull with an EPD for weaning weight of +25.0 pounds means that the bull's offspring should average 25.0 pounds more at 205 days of age than offspring of a bull with an EPD for weaning weight of 0.0 pounds.

77. EPD Abbreviations n BW = Birth Weight n WW = Weaning Weight (205 days of age) n YW = Yearling Weight (365 days of age) n milk = maternal milking ability expressed in pounds of calf weaned.