GENETIC EVALUATION

• Heredity – transfer of genetic characteristics from parents to offspring by the process of fertilization.
• Progeny – offspring; descendant or the descendants of a person, animal, or plant.
• Estimated Breeding Value – science-based, industry-tested measurements of heritable traits that can be tracked and measured.
• Estimated Breeding Value – measure of genetic merits that can be passed to progenies.
• Expected Progeny Difference – prediction of how future progeny of each animal are expected to perform relative to the progeny of other animals listed in the database.
• Heritability - measures the relative importance of hereditary and environmental influences on the development of a specific quantitative trait.
• Heritability – measure of the degree (0 to 100%) to which offspring resemble their parents for a specific trait.
• Heritability – partial description of one trait in one group of animals at some particular time.
• Heritability – amount of phenotypic (observable) variation in a population that is attributable to individual genetic differences.
• Heritability:

  H2 = Vg /Vg + Ve
• Heritability or h2: tells the breeder how much confidence to place in the phenotypic performance of an animal when choosing parents of the next generation.
• For highly heritable traits where h2 exceeds 0.40, the animal's phenotype is a good indicator of genetic merit or breeding value.
• For lowly heritable traits, where h2 is below 0.15, an animal's performance is much less useful in identifying the individuals with the best genes for the trait
• Expected Progeny Difference – Gold Standard for evaluation of genetic merit for a variety of important traits.
• Expected Progeny Difference – expressed as differences.
• Expected Progeny Difference – units are industry standards for each trait (kgs, inches, percent, etc.).
• Expected Progeny Difference – can be expressed as positive or negative.
• Expected Progeny Difference – useful only when comparing animals.
• Accuracy – reliability that can be placed on the EPD.
• Accuracy – ranges from .00 to 1.00
• Accuracy – accuracy close to 1.0 indicates higher reliability.
• Economically relevant traits - traits that directly influence either a cost or an income from beef production.
• Economically relevant traits:

  Probability of calving ease

  Sale weight

  Stayability

  Heifer pregnancy rate
• Indicator traits - traits not directly related to a cost or income from beef production.
• Indicator traits:

  Birth weight

  Weaning weight

  Yearling weight

  Calving records, interval

  Scrotal circumference
• Expected Progeny Difference - denote the breeding value of an individual animal's progeny.
• Estimated Breeding Value - denote the value of the individual animal.
• EPD is equal to half of an animal's EBV as half of an animal's genes are passed to the next generation.
• EPD = EBV/2

  EPD = ½ EBV