BREEDPLAN is a system of genetic evaluation of beef cattle developed by the Agricultural Business Research Institute (ABRI) in conjunction with the Animal Genetics and Breeding Unit (AGBU), both of which are located at the University of New England, Armidale, New South Wales. It is recognised as the most advanced system of genetic evaluation in the world and is now used by over 30 breed associations in Australia as well as in the USA, Canada, UK, New Zealand and Argentina.
The system calculates Estimated Breeding Values (EBVs) for a range of traits including birth weight, growth, milking ability, fertility and carcase information. The EBVs take into account not only the animal’s own performance, but also the performance of all its recorded relatives as well as the relationships between traits. For more information on the various individual EBVs see BREEDPLAN EBVs.
BREEDPLAN compares and ranks all animals of the one breed within a herd, while GROUP BREEDPLAN compares all animals, across participating herds, within a breed.
EBVs are expressed in measurement units, e.g. kg for weight, cm for scrotal size and mm for fat. They can be positive (+ve) or negative (-ve) depending on whether an animal’s genetic potential is above or below a base, which is a constant figure to which all animals in the herd or breed are compared. The base is constant and is set at zero for each herd or breed.
The EBV figures should always be compared between animals and the expected progeny difference is half the difference in the EBVs of the parents, since the progeny receives half the genes from the sire and half from the dam.
For example, in comparing two bulls, Bull A with an EBV for 600-day weight of +40kg and Bull B with an EBV of +10 for the same trait, the difference in their EBVs is 30kg. As a result, the progeny of Bull A would be expected to be 15kg heavier than those of Bull B at 600 days of age. The expected progeny difference is the average that would be expected over a large number of progeny (it is not what would be expected for each, and every, progeny).
EBVs have an accuracy figure associated with them. This reflects the amount of information that has been available in determining the EBV. The higher the accuracy figure is, the less likely the EBV is to change, as more information becomes available.
In determining which bull to buy or use in a herd, or which cows to use to breed replacement heifers, it is not always the animal with the highest EBV that should be selected. For birth weight, for example, often a bull with a low, or even negative EBV might be selected, depending on the potential in the herd for problems with high birth weight and dystocia. In many tropical breed herds, breeders look for bulls with adequate, but not the highest EBV for milk, as high milk production, in some herds, is thought to be associated with lowered fertility. Even for the growth rate traits depending on the market, breeders may choose bulls without the highest EBVs as the best to use in their herds. Beef producers may consider using $Indexes (see BreedObject for more information).
Beef producers should also consider the genetic relationships between traits, meaning that selection for one trait may cause a change in another trait. The change may be desirable or undesirable. For more information it is suggested beef producers attend a Breeding EDGE workshop.
It should be noted that EBVs will only be available if sufficient data has been recorded for that trait and as such, the full range of EBVs may not be available for each particular Breed Society/Association.
Always compare an EBV to the current breed average EBV for that trait.
A Percentile Bands table exists for each breed. This table allows assessment of where each animal’s individual trait ranks within the breed.