Droughtmaster GROUP BREEDPLAN is an internationally accepted advanced genetic evaluation system that provides a genetic description of Droughtmaster cattle for a comprehensive range of traits influencing fertility, growth and carcase performance.
It provides predictions of the genetic merit of individual animals called Estimated Breeding Values (EBVs). These EBVs are used by Droughtmaster breeders and commercial bull buyers to assist in selection decisions and purchase of breeding stock. EBVs are now accepted by most beef producers as a tool in the breeding and marketing of seedstock.
EBVs are based on all available pedigree and performance records provided by breeders. EBVs provide the best means for comparison of the relative genetic merit of animals across the breed for those traits included in the analysis. EBVs obviously cannot be used in isolation in any selection or purchase decision. Visual assessment is still necessary for those characteristics not adequately described by EBVs.
In the calculation of EBVs all available pedigree and performance information on each animal and its relatives (parents, ancestors, siblings, progeny, etc.) is combined to provide a single best estimate of an individuals genetic merit for each trait. In addition, allowance is made for environmental differences between properties, seasons and management on each animal’s performance. Differences in heritabilities between traits and genetic associations between traits are also accounted for in the calculation of EBVs.
The full methodology behind Group Breedplan can be lengthy and complex to explain, so should you like a comprehensive explanation of Group Breedplan we suggest you visit http://www.droughtmaster.com.au and click on the Breedplan link or http://breedplan.une.edu.au
The Salter family advocate that cattle must have the correct physical traits for structure and fertility before the consideration of Breedplan figures.
Glen Fosslyn stud is a founding member of Droughtmaster Group Breed Plan and participates with milk, growth, mature cow weight and scrotal size traits, all of which are easily measurable, and economically important.
A quick comparison of Glen Fosslyn Droughtmasters to others indicates high growth and a good balanced combination of mature cow size, milking ability and scrotal sizes. The high growth rate of the Glen Fosslyn cattle is demonstrated by the average of every registered animal in the Glen Fosslyn herd being in the top 15% of all recorded Droughtmaster cattle for the 200 Day Growth, 400 Day Growth EBV’s and in the top 10% for 600 Day Growth EBV’s for 2004 born calves.
The Glen Fosslyn Stud provides EBV data on the following traits;
- 200 Day Growth EBV (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 an animal's genetic merit for growth to early ages.
- 400-Day Weight EBV (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 an animal's genetic merit for yearling weight.
- 600-Day Weight EBV (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 an animal's genetic merit for growth beyond yearling age.
- Mature Cow Weight EBV (kg) is based on the cow weight when the calf is weighed for weaning, adjusted to 5 years of age. This EBV is an estimate of the genetic difference in cow weight at 5 years of age and is an indicator of growth at later ages and potential feed maintenance requirements of the females in the breeding herd. Smaller or more moderate EBVs are generally more favourable.The Mature Cow Weight EBV may also be used by bullock breeders wishing to grow animals out to a larger weight.
- Milk EBV (kg) is an estimate of an animal's milking ability. For sires, this EBV indicates the effect of the daughter's milking ability, inherited from the sire, on the 200 and 400 day weights of her calves. For dams, it indicates her own milking ability. Certainly a cow with a -3 EBV indicates poor milking, but at the opposite end a +5 upwards may indicate a good milker, who may “overdo” the milking and not go back into calf annually.
- 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 estimate of a sire's genetic merit for scrotal size and is positively correlated to age of puberty in female progeny.