Grazing cattle do not seem to suffer from manganese shortage, probably
because their manganese requirements are met by the herbage they consume.
Manganese deficiency is a more serious problem in domestic animals such as
poultry, non-grazing cattle and pigs. The main reason for this is that protein
supplements of animal origin (dried milk, fish meal, mean meal) are usually low
in manganese.
To promote strong legs in poultry, and to keep up normal egg production,
it is necessary to supplement their feed with about 40 mg of manganese per kilo
of weight. For ruminants, the requirement for optimal skeletal development is
only 20-25 mg/kilo. Soybean meal, important in poultry raising, contains 30 to
40 ppm manganese.