Our son has always had a bottle for his 11am fe...

Our son has always had a bottle for his 11am feed (usually with epxressed milk up until about a month ago). He took to the formula really well but it is getting to be a real mission feeding him his bottle as all he is interested in is playing with it, sucks a bit then pulls my hair etc. He is very easily distracted. Only ends up drinking 100mls. I am really keen to wean to formula now and give up BF but it is putting me off spending a good half hour trying to feed him his bottle. He drinks fine off me and has four milk feeds a day. Has anyone had success with feeding from a sippy cup.....? Maybe he isn't hungary enough and should I delay the milk feed a bit. Just a bit confused what to do!