I just put them on ad-lib after a few days much easier than messing with bottles and more natural and prevents bloat/scours. The feeding buckets are cheap. I just mix a bucket full a day and pour in the feeder.
Mine have milk, water, hay, straw, mineral lick blocks (cos one was floating about) lucerne pellets and seaweed meal from a week or so. I dont have a suitable place to put them outside at the mo.
Seem to have some cracking well lambs for little messing. You can add some live yogurt to the milk mix to help put the good bacteria back into the gut.