2.  Mating animals to produce certain characteristics  Low Birthweight  Heavier Weaning Weight  Color  Horned or Polled  Temperment

3.  Animals are the result of Feed, Health, and Inheritance (genetic material)  Feed is fastest to correct  Genetics last longest

4.  All body cells contain “Blueprints” with instructions as to how an animal will look or act etc.  One Gene comes from each parent (pairs)  Genes are divided into sections (Chromosomes) that carry genes  Sex chromosomes: male = XY, female = XX

5.  Dominant Genes = one gene overshadows the other  Angus Cattle: black is dominant, red is not (Bb)  Hereford: white face is dominant (Ww)  Hampshire Hog: white belt is dominant  Horns are dominant (Pp)

6.  The gene that is overshadowed by a dominant gene  Recessive genes can only express themselves if both genes are recessive  Polled vs Horned (Pp) (pp)  Black wool vs white (Ww) (ww)  Dwarfism vs normal size (dd)  Albino

7.  P = horned  p = polled  If a homozygous horned cow (PP) is mated to a homozygous polled bull (pp), what percent of the calves will be horned, polled?

9.  If a homozygous horned cow (PP) is mated to a heterozygous horned bull (Pp), what percent of the calves will be polled?

11.  Some recessive genes are attached to the X and Y chromosomes  Humans: Colorblindness and Baldness are on the X chromosomes  In Men, traits expressed anytime present  In Women, must have two recessives to show trait  Children get baldness from mothers

16.  If both genes express themselves  Shorthorn Cattle: Red male mated to a White female = Roan calf  RR + WW = RW

17.  Shorthorn Cattle  R = Red  W = white  RW = roan  If a red bull (RR) is mated to a white cow (WW), what color will the calves be?

19.  If a red bull (RR) is mated to a roan (RW) cow, what color will the calves be?

22.  Dwarfism  Monorchid = only one testicle descends  Cryptorchid = no testicles descend  Short ears & tails

23.  Dramatically different from what is expected genetically  Horned calf from polled parents  Loss of some or extra body parts  Lethal Mutation: causes death at birth  Sublethal Mutation: limits animals ability to grow to maturity  Beneficial Mutation: loss of tail in lambs

24.  Similar to a Mutation, only it is caused by something in the environment  Siamese twins

25.  Chance that traits will be inherited  Low: multiple births, fat covering  Medium: birth wt, wean wt, milk, wool grade, carcass wt, rate of gain  High: Loin eye area, fleece length & quality

26.  Currently have ewes that wean 70 lb lambs  Want to raise weaning wt to 110 lbs  Select a ram with a wean wt of 110 lbs  Heritability of weaning wt is 30%  What can you expect new lamb crop to weigh at weaning?

27.  What is the difference in current weaning wt and that of the new ram? 110 - 70 = 40 lbs  Heritability % x difference 30% x 40 = 12 lbs  Can expect a gain in weaning wt of 12 lbs  70 lbs + 12 lbs = 82 lbs

28.  Random Mating: all males have an equal opportunity to mate with all females  Outcrossing: mating purebreds with unrelated purebreds  Inbreeding: mating related animals  Linebreeding: parents mated to offspring  Crossbreeding: mating animals of same species but different breeds

29.  Offspring will outperform either of the parents  Corn Breed A yields 100 bu/acre  Corn Breed B yields 100 bu/acre  Crossbreed A & B yields corn that yields 200 bu/acre  Vigor only expressed in crossbreeding  Donkey mated to a horse = Mule  mule is sterile

30.  Animals not common to United States  Difficult to define today  New breeds are exotics

31.  Genotype: genetic makeup (Bb)  Phenotype: physical appearance (Black)  Heterosis: Genes are different, Dominant & Recessive (Bb)  Homozygous: both genes are the same (BB or bb)