Effects of Dietary Protein and Iron on Reproduction and Iron-Related Blood Constituents in Swine

Attempts to increase the transfer of iron from the sow to her offspring, either by placental transfer or mammary secretion, have led to variable conclusions. Chaney and Barnhart (1963) and Hansard, Lowe and Throsen (1964) reported that the level of iron in sow milk could be increased by feeding diets with high levels of iron. Other reports by Hooks (1964), Miller et al. (1964) and Veum et al. (1965) do not agree. Hansard (1965) reported a high correlation between levels of iron in serum and in milk of sows; whereas, a report by Miller et al. (1967) does not agree with this observation. Hahn et al. (1939) reported that iron in the circulatory system is bound to a beta-globulin molecule. The iron-binding capacity can be altered by dietary level or source of protein according to Cartwright and Wintrobe (1948), Cartwright et al. (1948), Klavins, Kiney and Kaufman (1962), Roehm and Mayfield (1963), Bhattacharya and Esh (1964a, b) and Brown (1967).