The researchers studied how body weight in New Zealand White rabbits changes as they grow. They used 48 rabbits and measured their weight weekly for 12 weeks. They found that genetics play a role in determining the rabbits' weight, especially before and after weaning. The rabbits' weights were positively related at different ages, with the strongest correlations seen before weaning. This suggests that choosing rabbits based on their genetics after weaning can help reduce the influence of the environment on their growth.