The value of weaning weight

A most common question is ‘what is the value of extra weaning weight?’ Say, a supplier comes knocking on your door with the next additive for the lactating sow feed. It costs 20 euros per kilogram (huge gasp goes here!) and you need one such kilogram per metric tonne of feed. This will give you an extra 500 grams on your current weaning weight, which at 21 days of age is lamentably too low, at 5.5 kg per piglet (summer and all that, you know). So, we assume the sow consumes a (hugel