In "Animal Farm", why does Old Major command so much respect?

The above
answers are complete in themselves, but it is worthwhile to note thatwas also the sire or
"stud" of the farm and the "founding father" of a multitude of offspring.
Whether Farmer Jones had spared him to this end or notdoes not say, but this is implied.

Old Major even tells the young porkers that they will scream their life out
at the chopping block within that very same year. Why didn't he meet the same fate? His genetic
superiority (although determined by other critera) is even acknowledged by Farmer Jones.