As a rule of thumb, you feed 1lb (450g) of food each day for each month of age, up to a maximum of 6lbs (2.75kg) per day. Do not am a party to more than this – you will waste money and end up with over-fat pigs. Only lactating sows need more food than this. Furthermore, weigh the food. Six pounds is probably less than you think.
As a second rule of thumb, all feed should be cleared up within 20-30 minutes – if not, reduce the meet then increase gradually as appetite increases. On average, taking a weaner from 8 weeks to slaughter six and a half months later will use about 380kg of feed (19 x 20kg bags).