EBV’s or Estimated Breeding Values are a prediction of the expected difference between two animals for the performance of their progeny. In other words, it is the breeding potential of a particular animal for inherited traits.
These traits include:
Reproduction – Scrotal Circumference, Days to Calving, Gestation Length
Weight traits – Birth Weight, 200day, 400day, 600day and Mature Cow Weight
Milk – (the additional weight contributed by the dam’s milk to her progeny’s weaning mass)
Carcase Traits – Carcase Weight, Rib Fat, Rump Fat, Eye Muscle Area, Intramuscular Fat (marbling) and Retail Beef Yield and are calculated based on information recorded for the animal’s own performance, the performance of its relatives and most importantly, the performance of its progeny. Many more useful EBV’s are available from BREEDPLAN such as Docility, Calving Ease, Udder Score, Teat Score, Longevity, etc. and it is the Society’s goal to participate in all these areas in the future.
The SA Limousin’s EBV’s are calculated by BREEDPLAN using BLUP technology = Best Linear Unbiased Prediction. These EBV’s are given in the same units as the recorded traits (e.g. kg for growth traits) and are expressed relative to the breed’s average for a specific base year. For South African Limousins this base year is 1986. The breed average of 1986 is then set to 0 with positive values being larger than the average, and vice versa. A bull with, for example, a Weaning Weight EBV of +6kg has an expected breeding potential of 6kg heavier, and would be expected to produce a calf weighing 3kg heavier at wean, than a bull with an EBV of 0. This value is half as only half the genes come from the bull, the other half from the dam. EBV’s can only be compared within a breed and are always compared to the current breed averages which, after our most recent EBV run in June 2007, stand as follows:
|2004 born calves||2005 born calves|
|Mature Cow Weight||+19kg||+22kg|
|Eye Muscle Area||+0.3cm²||+0.3cm²|
EBV’s have experienced a vast increase in popularity over the past few years as they make the selection process much simpler. Not only do EBV’s give you a prediction of an animal’s breeding potential in “black and white”, but it also takes out environmental effects allowing you to compare animals in different herds, different areas and even different provinces. In conjunction with visual appraisal and line & pedigree information it allows selection on a holistic basis. Comparisons can also be made between animals across time allowing measurement of genetic progress. Genetic progress is charted by BREEDPLAN yearly, on both a national and individual herd basis. This provides a valuable check for breeders and can be an important marketing tool for convincing commercial customers that the breed is improving. These reports are available on the internet under “Breed Database” at all times.