A number of significant BREEDPLAN software enhancements, along with the addition of extensive research data, will occur for the April 2020 Droughtmaster BREEDPLAN evaluation and then be included in subsequent analyses.

These enhancements include:

• Upgrade to BREEDPLAN version 6.2 – The Droughtmaster evaluation will now be using the latest version of the BREEDPLAN software, which includes a number of enhancements: greater range of traits that can be analysed; improved method for handling different groups of “base” animals; improved modelling of days-to-calving records for tropically adapted breeds; capacity for including genomic data via single-step methods.
  
  
• Revised adjustment factors and genetic parameters – The adjustment factors and genetic parameters used in the Droughtmaster BREEDPLAN analysis have been re-estimated by the Animal Genetics & Breeding Unit (AGBU). The genetic parameters include the heritability of each trait and the correlations between the different traits. The adjustment factors are those required for the performance records to remove the non-genetic effects of age and age of dam. Re-estimation of genetic parameters is a standard practice that is undertaken periodically for all breeds and ensures the BREEDPLAN analysis is kept relevant for the given cattle population, in this case Droughtmaster.  
  
  
• Inclusion of data from the Northern Multibreed Research Database – For the first time, intensive phenotypic records collected as part of the Repronomics Project over six years, will be included in the Droughtmaster evaluation. This comprehensive dataset represents over 100 Droughtmaster sires, many of which previously had no EBVs available. The data includes over 5000 animals (Droughtmaster, Brahman and Santa Gertrudis) that have been recorded for the full range of BREEDPLAN traits including: gestation length, birth weight, 200, 400, 600 day weights, mature cow weight, ultrasound scans, flight time, and abattoir carcase and meat quality traits.  The females have days to calving records, along with the new measures of heifer age at puberty and lactation anoestrous interval of first-calf cows, but until Droughtmaster go to single-step these new measures are not included.
  
  
• Transition to a full crossbred analysis model - The inclusion of extensive research data now allows the Droughtmaster analysis to move to a full crossbred configuration. This enables animals of different breed compositions, if recorded together, to remain in the same contemporary group, and for their performance to be adjusted for heterosis.  Previously, Droughtmaster BREEDPLAN was running a restricted crossbred analysis where crossbred animals were included in the analysis by contemporary grouping them based on their breed code.  EBVs on crossbreds in the evaluation from now on will be directly compared with EBVs from purebred Droughtmaster animals.
  
  
• Four new traits – The introduction of the northern research project data allows for the inclusion of four new traits into the Droughtmaster BREEDPLAN analysis. These traits are Gestation Length, Days to Calving, Shear Force and Flight Time.
   
  • Gestation Length is defined as the period from the date of conception to when the subsequent calf is born. Gestation Length EBVs are calculated from both the joining date and date of birth records for calves conceived by either AI or Hand Mating, but not by natural matings.  Gestation length is measured in days, with lower (i.e. more negative) EBVs being associated with shorter gestation length.
    
    
  • Days to Calving EBVs are estimates of genetic differences between animals in the time from the start of the joining period under natural mating until subsequent calving. Days to Calving EBVs are expressed in days, with a more negative EBV being more favourable. A shorter time from the start of mating to calving is mostly indicative of a shorter time to conception.  These EBVs are calculated from the natural joining records submitted for both heifers and mature cows.  Currently there are limited records being used from the Droughtmaster database and it is strongly recommended that breeders who have historic records contact TBTS staff for assistance in submitting these records to Droughtmaster BREEDPLAN.
    
    
  • Shear Force EBVs are estimates of genetic differences between animals in meat tenderness. Shear force is measured in the kilograms of shear force that are required to pull a mechanical blade through a piece of cooked meat and are based upon direct carcase measurements. Shear force EBVs are expressed in kg and lower (more negative) are predicative of lower shear force i.e. more tender meat.
    
    
  • Flight Time EBVs are estimates of genetic differences between animals in temperament. Flight time is the time taken (in seconds) for an animal to travel approximately 2.0 metres after leaving the crush.  Flight Time EBVs are expressed in seconds and higher EBVs (i.e. more positive) are predictive of longer flight times (i.e. better temperament).

Please Note: The above enhancements could result in EBVs changing significantly for some animals.  In some cases, the rankings of animals may also change.

If you have any questions regarding the enhancements to Droughtmaster BREEDPLAN or changes in EBVs resulting from the enhancements, please contact Droughtmaster TBTS Technical Officers Paul Williams (P: 0427 018 982, E: paul@tbts.une.edu.au) , Tim Emery  (P  0408 707 155, E: tim@tbts.une.edu.au) or Droughtmaster BREEDPLAN (P: 02 6773 3555 E: droughtmaster@breedplan.une.edu.au).