Dairy: Genetics and Biotechnology

Body Condition Score

Genetic Merit For Production

Australian Breeding Value

Genomics

Australian Dairy Herd Improvement Scheme (ADHIS)

Genetic Correlation

Genes have an effect on several traits, so a change in a single gene will affect all those traits

Heritability: allow for phenotypic selection

Repeatability/correlations: Milk yield between 1st and 2nd lactation, conception rate between years

Estimate of bulls genetic merit (must be halved)

Production traits expressed in units of measurement (e.g. L of milk)

Type traits expressed in standard deviations

Management traits (e.g. fertility) expressed as %

Uses DNA to predict merit of bulls/cows

Used to calculate AVBs of sires and females

Double the reliability of AVBs values based on pedigree alone

Advantages for farmers

Reliable

Can be used to identify superior animals e.g. embryo transfer elite heifers, target sexed semen

High genetic merit cows respond better to high concentration pasture than low genetic merit cows

Assessment of the proportion of body fat a cow possesses

Assess nutritional status

Good indicator of how provided diet meets energy needs of cows

Under and over conditioning of cattle pre-disposes them to diseases