Is prepayment of Zakah on thirty head of cattle, where one young bull (Tabi') is prepaid, sufficient if thirty heifers are born, the mothers die, and the Hawl passes on the heifers?

Primary text

There is uncertainty regarding whether the prepaid young bull suffices for the thirty heifers. One view suggests it suffices because the heifers follow the original stock in the Hawl. The counter-argument is that if the young bull was prepaid while the mothers remained alive, it would not suffice for the mothers, thus it should not suffice for the offspring when the prepayment was made concerning something other than the offspring.