Again I would point out that I am ram breeder with my own sale so I am not a neutral commentator, but as such I do think I have a good practical understanding of the value, reliability and pitfalls of such figures.
Dual Purpose Production (“DPP”) or Dual Purpose Overall (“DPO”) indexes
“Dual purpose Adult Size” index (“DPA”)
Some are genuine for excluding it as the index itself is, in my view, at present a complete waste of time. Firstly if you don’t weigh your ewes (which is still the majority of breeders) SIL then calculates this DPA figure based on the rams early growth breeding values eg the weaning weight breeding value (‘Wwtbv”) and the live weight 8 (8 months old) breeding value (“lw8bv”): if a ram has a particularly high lw8bv, then SIL will give that ram a high negative DPA based on the assumption that such high early growth will mean bigger adult sheep. This is true for some sheep, but not all; accordingly the DPA figure is a waste of time because it can’t be relied on. I had a great example myself with one of my best breeding Romney rams in the last 10 years: he had phenomenal early growth (450 grams a day for 3 months), but he himself as an adult was not a big sheep nor in fact were the majority of his progeny (he actually reduced the size of our ewes), but he had a lousy DPA.