This is some what puzzling, now that 2 cows are on or are near the borderline limit for any possible breeding then why a bull was not imported with any younger cows instead?.
My own view would have been bringing in 1 bull with the three cows from the start?.
Why bring in any females nearing the borderline age with no provision made for even housing a bull then or even now?. I can't follow this situation?
It's possible that they felt having the cows on site would strengthen their case for importing a bull and in the meantime give them non contact animals to work with. The cow facilities would have been simpler to construct than the facilities a bull would require, so they prioritised what could be done first and bring maximum benefit to their zoo.
I don't see not breeding from the two elder cows as a major issue. Asian elephants are breeding well in Australasia and we can hardly claim as a region to have maximised use of the founder cows we have. Two cows is likely what Australia Zoo can breed and accommodate calves from, with the other two merely providing support to them via a matriachal herd.
