Fathers do not need any protection from the old law.
At common law, a man is the father of all children born of his legal wife. DNA testing would not, and should not IMO, affect this.
HOWEVER...
At common law, these children and "children" belong to the father/husband, and may not be removed from his care and protection, not even by the Crown. The idea that the children belonging to a man would be turned over to an ignorant slut and that he should pay her for the privilege is ludicrous.
Restore the old law, and fix the problem.