We use barley sprouts which we produce on site and require no supplementation to increase weight.
We add bran, salt and diatomous earth to raise mineral input and assist in eliminating worms, this is given as a supplementary wet feed in the evening.
This costs about 70p per adult pig per week, an adults requirements are met with 2k spouted barley a day supplied in two feeds. Halve the amounts if the pigs are grazing/foraging clover rich grass. Farrowing/weaning sows receive (up to) 4kg barley sprouts daily. Weaners 1/2kilo twice a day.
Barley spouts at four to six days provide 14% protein, 5%roughage and 10%fibre.
We soak barley seeds for 12 to 24 hours, spread them out on damp cloth in trays and expose to light when they have sprouted. In winter we spread the seeds in trays in a shed and expose to a 10watt diode UV/IR light system overnight, this illuminated 6 square meters of trays.
1kg barley seed yields 7kg barley sprouts, we pay £85 a ton for barley seeds locally so this is a very low cost system.