Why did the Daleks use pigs to make pig-slaves?

Question

In "Daleks in Manhattan" and "Evolution of the Daleks", Daleks from the Cult of Skaro use a genetic laboratory in 1930 Manhattan to turn residents of the slum of Hooverville into pig-slaves, which they use a labor and guards.

Why did the Daleks choose to use pigs for the human hybrids? A couple of things make me question this:

• Pigs aren't too genetically similar to humans.
• Pigs don't have many qualities that make them good fighters/workers, when compared to other animals.
• There aren't a lot of pigs in Manhattan.

There are much better choices out there. So why did the Daleks choose to make pig-slaves?

Answer 1

IANAMS, but I have worked with the odd Mad Scientist or two.

Pigs are more medically compatible with humans than you'd think:

Pigs share a number of surprising comparable traits with humans. For instance, we both have hairless skin, a thick layer of subcutaneous fat, light-colored eyes, protruding noses and heavy eyelashes. Pig skin tissues and heart valves can be used in medicine because of their compatibility with the human body.

Quote is from mnn.com and also references xenotransplantation article on the same site.

Insulin from pigs has also been used in humans; to quote Wikipedia with emphasis mine:

Insulin from [cow/horse/pig/fish] is effective in humans as it is nearly identical to human insulin (three amino acid difference in bovine insulin, one amino acid difference in porcine).

In addition, as any Babe could tell you, pigs are smarter than they look:

Pigs can often outsmart dogs and are on about the same intellectual level as our closest living relatives, chimpanzees, according to a new paper.

(That's discovery.com describing a paper published in the International Journal of Comparative Psychology).

All in all, I think pigs would not be the worst choice the Daleks could have made. In 1930's NYC, the half-pony, half-monkey hybrid was out of their reach.