8 month old won't drink milk in the day but wants to feed all night

[Gangle]

I've been back at work for almost a month and really worried as DS, 8 months, is barely drinking any milk during the day, usually around 60 or 70ml. I think this is because he doesn't like the bottle. He then wakes up around 11pm, 3am and 5 or 6am for further feeds and I feel I can't refuse him because he is taking so little during the day. We've been doing sleep training and the person helping us has devised a way to try to get him to feed less but I'm so tired at the moment from working full time and looking after DS that I just want to go the path of least resistance. My main concern is that he isn't getting enough milk as all the books say they need 600ml per day for the first 12 months although he is maybe getting this from his 3 night feeds. Can you be sure they take as much milk as they need?

This might not help much, but I was in a similar situation. DD really isn't keen on the bottle, so had a tippee cup. At nursery she only had a couple of sips of milk for about a month (maybe longer). I fed her as soon as I got home, and we have a bedside cot and I feed on demand at night, I found that so long as I didn't have to get up in the night I was able to do this and although I'm normally a bit tired, I'm not totally knackered as I would be if I was getting out of bed to see to her. She has always eaten well at nursery and since she seemed happy and healthy I didn't worry about whether she was getting enough milk.
She is 13mo now and I am trying to get her to sleep through, at the moment I am not feeding before 3am and dh is putting her to bed, she is now getting easiser to settle and feeding for shorter periods at night. When she is teething though she uses me as a dummy. Oh and she drinks more milk at nursery now, its like she suddenly thought ok, since mum isn't here I might as well drink this. HTH