ANEQ 101: Genetic Prediction and Genetic Improvement

Vocabulary practice flashcards covering foundational concepts of animal breeding, genetic models, repeated traits, heritability, selection factors, molecular genetics, and pulmonary arterial pressure from the ANEQ 101 lecture.

Genetics

The study of inheritance and variation in living organisms.

Inheritance

The transmission of hereditary factors from one generation to another.

Variation

Difference or deviation from the normal.

Animal Breeding

The application of knowledge of genetics to the improvement of animals.

Basic Genetic Model

The fundamental mathematical equation partitioning an animal's performance into genetic and environmental components: $P = G + E$ or $P = BV + GCV + E$.

Environmental Effects ($E$)

The effects of external, non-genetic factors on animal performance, including feeding and nutrition, location, climate and weather, and age.

Genetic Model for Repeated Traits

The model representing repeated records of quantitative performance on an animal: $P = μ + BV + GCV + E_p + E_t$.

Permanent Environmental Effect ($E_p$)

An environmental effect that permanently influences an animal's performance across all repeated production records.

Temporary Environmental Effect ($E_t$)

An environmental effect that influences only a single specific production record of an animal without impacting subsequent records.

Breeding Value ($BV$)

The transmittable portion of an individual's genetic merit that represents the sum of the average effects of its alleles and can be improved through selection.

Gene Combination Value ($GCV$)

The non-transmittable ('creatable') portion of an animal's genetics resulting from specific gene combinations, improved through mating decisions regarding which male is bred to which female.

Progeny Difference

The difference between the mean performance of an individual's progeny and the mean performance of all progeny across all loci, mathematically equal to half of the individual's breeding value ($\frac{1}{2}BV$).

Heritability ($h^2$)

A measure of the strength of the relationship between performance (phenotypic values) and breeding values for a trait in a population, expressed as $h^2 = \frac{\text{var}(BV)}{\text{var}(P)}$ or $h^2 = \frac{\sigma^2_{BV}}{\sigma^2_P}$.

Lowly Heritable Trait

A trait characterized by a heritability estimate strictly between $0$ and $0.20$ ($0 < h^2 < 0.20$).

Moderately Heritable Trait

A trait characterized by a heritability estimate between $0.21$ and $0.40$ ($0.21 < h^2 < 0.40$).

Highly Heritable Trait

A trait characterized by a heritability estimate strictly greater than $0.41$ ($h^2 > 0.41$).

Selection

The animal breeding process that determines which individuals become parents, based on phenotype or results of genetic evaluations (such as EBVs or EPDs).

Mating

The animal breeding process that determines which specific males are bred to which specific females, utilizing selection criteria, pedigrees, relationship information, and crossbreeding or inbreeding systems.

Selection Intensity

A factor influencing the rate of genetic improvement that describes how 'picky' breeders are when selecting breeding animals.

Generation Interval

A factor influencing the rate of genetic improvement that reflects how quickly young, superior individuals replace older animals in the population.

Genetic Variation

The amount of genetic variability present in a population for a given trait.

Accuracy of Selection

A measure of how reliably and effectively breeders identify and select the animals possessing the best true genetics.

Genotyping

The process of using a laboratory to determine which DNA-marker alleles an individual animal carries.

Single Nucleotide Polymorphism (SNP)

A single base DNA sequence variation occurring in a population, which represents the most common type of genetic variation.

Chargaff's Rule

The base-pairing principle stating that in DNA, the amount of adenine equals thymine ($A = T$) and cytosine equals guanine ($C = G$).

Expected Progeny Difference (EPD)

A prediction of an individual animal's genetic merit calculated by combining pedigree, performance, and genomic data from breed-wide evaluations to predict offspring performance.

Pulmonary Arterial Pressure (PAP) Score

A physiological measurement in cattle with a heritability of $0.34 \sim 0.46$ used as an indicator trait for susceptibility to pulmonary hypertension and high altitude disease.

High Mountain Disease (Brisket Disease)

A condition in cattle caused by pulmonary hypertension (PH) occurring at elevations above $5{,}000\text{ ft}$, marked by edema and fluid accumulation in the brisket area.

Feedlot Heart Disease (FHD)

A form of pulmonary hypertension and congestive heart failure observed in cattle in feedlot settings at lower elevations (such as $4{,}100\text{ ft}$).

Economically Relevant Traits (ERT)

Traits that directly influence the bottom line and profitability of an animal production enterprise, serving as primary targets for genetic selection.