Vitamin B12 Requirement of Male Weanling Pigs Four Figures

Abstract

Six sets of 4 male litter-mate pigs, three per treatment, were individually fed and watered ad libitum from weaning to a weight of 75 lb. in wire floored crates. The pigs were fed a fortified corn-soybean oil meal ration to which were added 0, 5, 10, and 20 µg of crystalline vitamin B₁₂ per pound of ration. The ration treatments were subdivided, with one-half of the pigs receiving 40 mg of antibiotics per pound of ration. Vitamin B₁₂ alone produced only slight increases in daily weight gain but in the presence of antibiotics the increases were highly significant. There were no significant differences in responses among the added levels of vitamin B₁₂ as judged by the weight gain of the pigs. The addition of an antibiotic mixture to the ration increased average daily gains and feed efficiency significantly. There were no differences among treatments with respect to hemoglobin, red and white blood cell counts or total nitrogen in the blood. Antibiotics alone increased blood urea; however, when vitamin B₁₂ was added the blood urea was lowered. There was an increase of vitamin B₁₂ in the urine as the amount in the ration increased. This was also true with the feces, except for the 10-µg level with added antibiotics. Similarly, there was an increase in the vitamin B₁₂ content of the liver as the levels of vitamin B₁₂ in the rations were increased. The weanling pig needs vitamin B₁₂ for optimum growth and feed efficiency. With intestinal flora control through the use of a combination of antibiotics, the vitamin B₁₂ requirement of the weanling pig is 5 µg or less per pound of ration when the antibiotics are added to a corn-soybean meal diet. It is suggested that a mixture of antibiotics similar to the one used here might be used in studying the minimum requirement of other vitamins which may be synthesized in the intestinal tract of the pig.