How is aAa® different from “linear” and Genomics?
Linear evaluation looks at an animal’s single body parts, rating each part individually on a scale between two opposite extremes. Linear users would breed a cow that has an extreme body part to a bull who has the opposite extreme of the same body part, with the goal being to achieve a body part in the offspring that is somewhere in the middle between the two extremes.
aAa® analyzers begin by looking at all parts of an animal. They study the relationship of body parts, identify problems of form and function in the entire animal, find the causes of those problems, and determine what kind of bull will bring the qualities needed to prevent the same problems from occurring in the next generation. The goal is always balance in form and function of the animal as a whole.
Genomics identifies genes in an animal’s DNA in order to predict their influence on the animal’s development. It measures an animal’s genetic potential only, not how the functional expression of that genetic potential might be influenced by the animal’s physical form, environment, management, etc.
aAa® studies the form and function of living animals, identifying the qualities a cow actually possesses and the qualities a bull must bring to the mating in order to produce offspring with an optimal balance of functional qualities.
Both “linear” and Genomics are forms of evaluation. Evaluation makes a value judgment – is something good or bad? How good or bad is it? Is a value high or low? How high or low is it? There are many ways to evaluate dairy cattle including classification, linear evaluation, genomic indexes and progeny testing. Evaluation is an important way for dairy breeders to measure their progress in achieving their breeding goals.
Analysis is not the same as evaluation. Analysis determines natural patterns of an animal’s form and function regardless of how good or bad the animal may be. Here are some important differences between evaluation and analysis:
Identifies which animals are good and measures, scores or rates how good they are
Determines how animals are different regardless of how good or bad they may be
May evaluate single body parts independent of other parts
Looks at all parts and how they are formed and function together
Identifies problems and measures the extent or degree of the problem
Determines the nature or cause of problems in order to find solutions to help prevent the problem from recurring in the next generation
Identifies the best cows to keep and the best bulls to use for breeding
Guides the breeder in selecting a bull for each cow to provide qualities she needs in a mating
Ideals and standards vary from country to country and breed to breed
aAa® Animal Analysis is consistent throughout the world for all dairy cattle breeds
Using evaluation and analysis is not a matter of either-or. The most successful breeders use both. Evaluation helps determine the best cows to keep and the best bulls to use for breeding. Evaluation data is essential in choosing sires to help achieve your breeding goals. Analysis helps breeders make matings using the sires they choose in a way that will produce offspring that are balanced in form and function.