In recent years the use of antibiotics in swine nutrition has received
much attention. Research has shown that different vitamin B12 antibiotic
supplements stimulate gains.
Antibiotics have been shown to be effective in stimulating rate of
gain as much as 18 percent and improving the feed efficiency up to
10 percent when fed in the rations of swine. Not so conclusive evidence
has been obtained, however, to show that mere inclusion of an antibiotic
in a feed insures the improvement in the well-doing of the pig,
unless the antibiotic is fed in adequate amounts, which is from 5.0-7.5
mg. per pound of total feed.