Comparison of Predicted Proofs with Actual Proofs of GGBP bulls (August 07)
Young bulls selected for use in the GGBP are selected by the Breeders on the FOB (future of the breed ) Committee based on Pedigree Information, which comes from the performance of the Parents or in the case where a young unproven bull is the Sire , then the Grandparents performance is used.
Once the daughters start milking then their production figures are compared against daughters of other bulls in the same herd and then across the breed.
Because the GGBP bull semen has been used in Mainland and Guernsey Island herds, a good spread of daughters has been achieved and high reliabilities of the proofs are occuring.
The proofs of these first 20 bulls show that 14 have gained proofs that are greater than predictions, with 3 ( Oberon, SP Royal Oak and Pedro ) greater than 150% of the prediction, whilst another 7 ( Alacrity, Royal Highness,Storm, Hawk,Aaron and Hunter 2) greater than 125%.
All 10 of those bulls are sons of sires ( 6 different bulls) who were already proven when the sons were born and so had high reliabilities.
The 6 bulls that are below the predictions are (Ambassador [94%],Stingboy [80%],Rocket [71%], Tempest [55%],Pacific [52%] and Nimrod [39%] are with the exception of Pacific sons of bulls who were awiting proofs at the time of selection. The sires in question ( Stingray, Sonic and Jordan) failed to live up to their own predicted proofs and if that information had been available then it is unlikely that these bulls would have been used within GGBP.
The advice that EGCS recieved was that similar schemes in other breeds have delivered approx. 80% of the Parent Average in the proofs of the young bulls but these 20 bulls have delivered 113%.
I believe that in practice we should be pleased with these outcomes as there is no doubt that production levels continue to increase year on year and so do average Classification scores.
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