Understanding Shorthorn Breedplan
Not all cattle breeders are fortunate enough to have perfected a finely tuned cattle sense. Not all buyers of stock are blessed with that same sense. Performance recording provides both breeders and buyers more information on which to base their decisions.
The importance placed on performance figures or on appearance and type can depend on who is doing the choosing. However to not provide the information is leaving the job half done. Shorthorn Breedplan is the internationally accepted system of performance recording. It combines the known pedigree of an animal and the actual performance in a BLUP (Best Linear Unbiased Prediction) analysis to provide EBV’s (Estimated Breeding Values).
An EBV is based on the animals own performance plus the performances of all known relatives, sire, dam, half sisters, uncles etc. Information on one trait can also help predict other correlated traits.
Measurements required for Breedplan are:
- 200 day weights and
- either a 400 day or 600 day weight.
Additional information that is encouraged to be collected includes;
- Calving Ease
- Scrotal Size
- Scan for Fat
- Mature Cow weight
Breedplan only provides a within herd comparison and cannot be compared across herds.
Shorthorn Group Breedplan
Shorthorn Group Breedplan uses the pedigree links between herds through the use of common sires in Shorthorn Breedplan. These common sires form genetic links and its these links which allow across-herd and across year comparisons of Group EBV’s.
Where you see the Shorthorn Group Breedplan logo, then the EBV’s can be compared across herd and across years. Most Shorthorn stud herds are participants of Shorthorn Group Breedplan.
How to use EBV’s
Estimated Breeding Values (EBV’s)
In the database searches of this website (listed on the home page left hand menu as “Database Search”), you will find a powerful search facility that will allow the identification of animals from the current Shorthorn Group Breedplan analysis that satisfy your specific EBV requirements.
The following might make it easier to understand how to use EBV’s.
- The first step is to decide what characters are important in your breeding program, then select the EBV(s) which fits the bill for your herd.
- Gestation Length EBV indicates lighter birth weights and easier calving.
- Birth Weight EBV indicates the genetic potential for birth weight. The lower the birth weight EBV of a sire the lighter is the birth weight potential of his progeny.
- 200-Day Milk (kg) is an estimate of sire’s milking ability. This EBV indicates the effect of the daughters milking ability, inherited from the sire, on the 200 day weight of her calves.
- 200-Day Growth (kg) is calculated from the weight of progeny taken between 80 and 300 days of age. Values are adjusted to 200 days and for age of dam. This EBV is the best single estimate of a sire’s genetic merit for growth to early ages.
- 400-Day Weight (kg) is calculated from the weight of progeny taken between 301 and 500 days of age, adjusted to 400 days and for age of dam. This EBV is the best single estimate of a sire’s genetic merit for yearling weight.
- 600-Day Weight (kg) is calculated from the weight of progeny taken between 501 and 900 days of age, adjusted to 600 days and for age of dam. This EBV is the best single estimate of a sire’s genetic merit for growth beyond yearling age.
- Eye Muscle Area EBV (cm2) estimates genetic differences in eye muscle area at the 12/13th rib site of a 300kg dressed carcase. More positive EBVs indicate better muscling on animals.
- Rib Fat EBV (mm) estimates the genetic differences in fat depth at the 12/13th rib in a 300 kg dressed carcase. More positive EBVs indicate more subcutaneous fat and earlier maturity.
- Rump Fat EBV (mm) estimates the genetic differences in fat depth at the P8 site of a 300kg dressed carcase. More positive EBVs indicate more subcutaneous fat and earlier maturity.
- Scrotal Size EBV (cm) is calculated from the circumference of the scrotum, measured in centimetres and adjusted to 400 days of age. This EBV is an indicator of male fertility in regards to semen quality and quantity. Higher (positive) EBVs indicate higher fertility. Scrotal size is also positively associated with earlier age at puberty of bull and heifer progeny.
- Mature Cow Weight is an estimate of an animal’s potential for growth to maturity.
- Carcase Weight EBV is an indicator of the genetic difference in carcase weight at a standard age of 650 days.
- Retail Beef Yield Percent EBV indicates genetic differences between animals for retail yield percentage in a standard 300 kg carcase. Sires with larger EBVs are expected to produce progeny with higher yielding carcases.
- Intra Muscular Fat Percent EBV indicates genetic differences between animals for intra muscular fat percentage (marbling in a standard 300 kg carcase. Sires with positive EBVs are expected to produce progeny with higher average marble scores.
Accuracies are expressed as a percentage and give an indication of the amount of information available to calculate the estimated breeding value (EBV). The higher the accuracy, the lower the likelihood of change in the animal’s EBV as more performance information is gathered on the animal and its relatives.Note that the higher the accuracy, the more information you need to increase it. That is, significantly more information is required to change an accuracy from 90% to 92% than it takes to change an accuracy from 40% to 50%.
How Bulls Are Ranked on EBVs
All EBV’s are shown as + or – kg liveweight, EBV’s are relative (to other EBV’s) and are fixed on a set base level. This means that you can directly compare Group EBV’s across herds and across years.