The Influence of Vitamin B12 and Antibiotics on Protein and Energy Utilization in a Low Protein Diet

Abstract

The effects of a combination of vitamin B₁₂ and antibiotics on protein and energy utilization were investigated in a 70-day growth and body balance experiment with 12 litter-mate pairs of growing albino rats. One animal of each pair was fed an unsupplemented diet compounded to contain adequate quantities of all known essential nutrients except vitamin B₁₂, while its litter mate was fed the same diet, in equivalent amounts (paired-feeding), plus a supplement containing vitamin B₁₂ and antibiotics. The protein in the diet was of vegetable origin and was fed at a 10% level. The rats on the supplemented diet gained somewhat more live weight, stored more fat and less water, had less digestible and metabolizable energy and produced less heat than the animals on the unsupplemented diet. At the level of protein fed in this experiment there was no indication that a specific relationship existed between the utilization of nitrogen and the supplements used, which is in confirmation of previous work in which a higher level of protein was fed. The utilization of energy-producing nutriment absorbed from the intestinal tract was shown to be improved by the presence of vitamin B₁₂ and antibiotics in the diet.