Think its all in the breeding...

My girl Kimba's Spirit was a 25kg race bitch Her first litter to 29-30kg Big Daddy Cool produced 6 pups, 28,28.5 and 31 kg dogs 24,24,25kg bitches

Her next litter 2 pups to 32kg Hallucinate has produced pups that at this stage, the bitch who i kept is 8 months old... and when i last saw her 2 months ago, id say she was 26-27kg

Same whelper (myself) and same rearer as the BDC litter so cant say they were brought up differently