Which group of animals does Napoleon raise from youth after the rebellion?

Napoleon raises dogs from youth after the rebellion as part of his strategy to secure his power and establish a loyal enforcer group. He takes puppies away from their mothers to educate and train them in secret. This is critical because the dogs later become his bodyguards and enforcers of his will, instilling fear among other animals and helping him to maintain control over the farm. This action aligns with Napoleon's broader themes of manipulation and the use of power.

The other animal groups mentioned do not play a similar role in Napoleon's consolidation of power. Pigs, while central to the leadership, are not specifically raised by Napoleon in isolation from youth for this purpose. Cows and sheep serve different roles within the farm's dynamics and do not have the same instrumental function in ensuring Napoleon's authoritarian regime. This distinction highlights the strategic use of dogs as tools for dominance and control in the narrative of "Animal Farm."