I guess WendyW has more or less summed up the argument. Yes it is biologically preferable for a mum to breast feed, but some women are unable so to do - my wife was ubale to breat feed our youngest daughter because of DVT prevention drugs used during pregnancy including Wharfrin which would have poisoned her milk. But that is by no menas the only reason, some perfectly healthy mums simply don't take to the process, they find it painful, or they simply don't enjoy the sensation, and as Wendy says, it has to be the choice of the individual, and no-one should adopt the moral high ground on this issue.