Please can I refer you all to
this excellent explanation of the causes of bloat written by jaykay recently.
Personally I prefer to give them 3 x 350ml feeds rather than going up to 500ml until and unless I am quite sure they have room in the abomasum for 500 ml at a time. This reduces the risk of the abomasum overflowing and letting milk into the rumen, which as described by jaykay is one of the ways bloat can be caused.
At the moment I am keeping mine on 3 x 350ml to about 6 weeks, then dropping one feed every other day for a week. I like the way this works; I take them fresh creep - not too much! - when they are expecting that missing bottle feed, and they eat the cake because they are hungry and I haven't taken them a bottle
.
Starting the following week I give them just the two bottles every day, with cake in between as above, then drop one more bottle and stop milk at 8 weeks
provided I am sure they are eating plenty of cake and hayAll timings are approximate.