I've watched my father use a 22 rifle and drop a hog in the lot and cut his throat. Drag it out of the lot hang it up gut it and skin it out. At that point the carcass was taken into town to the locker where they cut it up, wrapped it and froze it.
As an adult while I was working in virus production producing Veterinary Virus Vaccines when they were still producing viruses using primary pig kidney cells as the substrate to grow bulk rabies virus. The kidneys of 30 to 40 lb hogs were were aseptically minced and planted in glass roller bottles where the individual kidney cells would attach to the glass and grow out producing a cell monolayer one cell thick. The tissue culture bottles were infected with seed virus and later harvest the fluids of bulk virus.
To get the kidneys with the help of an assistant I would use a stun gun to kill the hogs then cut their throats and hang them up and aseptically remove the kidneys. It was a bloody job that some assistants couldn't handle even though they were warned before hand just how gruesome it actually was. Once the hog was killed it was placed close to a drain in the floor in corner of the room where the throat was cut. When I was trained they would use the scalpel and cut the throat just below the jaw. Once I was doing it I would use the throat cutting technique I watched my father use where the knife blade was placed in where the neck attached to the chest so the knife blade would sever the larger veins and arteries coming off of and close to the heart and getting a much larger and quicker bleed. I would grade my self on the stick on just how high the blood would splatter on the wall in the corner.
At that time we were also using primary kidney cells of rabbits, cats and dogs to produce various other virus types like IBR, BVD bovine viruses and Canine distemper viruses and the least offensive technique involved producing equine eastern and western encephalo virus using chick embryos as the cell substrate for production. These other critters were put down using dry ice to suffocate them in plastic bags. Putting the puppies down I usually delayed going into the room and not have seen them while still alive before removing the kidneys.
Fortunately the virus vaccines today are not produced with primary cells like in the past. Now days various cell lines where the original critter was killed many years ago are used. The cell lines are frozen and grown out producing more cells which can be used for production or freezing down the subsequent cell passages.
“There is no difference between communism and socialism, except in the means of achieving the same ultimate end: communism proposes to enslave men by force, socialism—by vote. It is merely the difference between murder and suicide.” Ayn Rand