Vitamin B12 content of piglets and of milk from sows fed on rations containing animal or vegetable protein.

In recent years we have attempted to produce pigs 3-5 weeks old deficient in vitamin BIZ. The pigs were removed from the sow at 2 days of age and reared on a vitamin B,,-deficient synthetic-milk diet of the composition described by Neumann, Johnson & Thiersch (1950). Unlike the American workers, we were unable to produce such deficient pigs under our conditions and considered that differences in stores of vitamin B,, at birth might be responsible. To investigate this possibility we did an experiment in which several gilts were fed continuously for three gestations and lactations on a ration containing only vegetable protein, as normally used in America. The vitamin B,, content of the baby pigs produced by these animals, and the vitamin B,, content of their colostrum and milk were measured and compared with those of gilts fed on a normal British-type ration containing white-fish meal as the vitamin BIZ-rich protein supplement.