Why does slim drown the puppies?

The supposed reason is because Slim's dog, Lulu could'nt possibly feed all of

the pups, so Slim decided to drown the smallest of the pups, keeping the big

healthiest ones to live. This action shows symbolism of one of Steinbeck's

reoccuring themes, which is basically states that there is no room or tolerance

for the weak and useless, especially in an environment of unlimited resources.

This theme is somewhat of a cruel reality to the main characters, realizing that

the ranch doesn't consider the welfare of its weaker members, but it also

stands as one in which those who hold power wield it irresponsibly.