I have 2 greek spur thighs that i bought in sept 2012,They were only a few weeks old one weighed 14 gms and the other 18 grms,the 14 grms 1 now weighs 320 gms but the 18grms 1 weighs 1470 ,only fed on weeds,both are fed the same,i feed them seperately now because i thought he might be eating the other 1's food but in the last 2 months hes put on 260 grms.He looks ok ,doesnt look as if hes had a growth spurt or anything,if he keeps growing at this rate he's going to be huge. Could it be a medical problem