Effect of Ferrous Fumarate in the Lactation Diet on Sow Milk Iron, Pig Hemoglobin and Weight Gain

Two experiments involving 22 litters were conducted to study the effects of adding ferrous fumarate to the lactation diet on iron level of sow’s milk and on weight gains and hemoglobin levels of suckling pigs. Ferrous fumarate was not effective in increasing iron content of milk, when added to the lactation diet at a level of 1984 mg. of iron per kg. The increase in hemoglobin level observed at 24 days in Experiment I and at 21 days in Experiment II, in litters nursing sows fed ferrous fumarate, was due to the pigs’ obtaining a source of iron from the sow’s feed and feces. When this contamination was prevented, no significant increase in hemoglobin level was obtained. Pigs injected with iron dextran were not significantly affected by the sow’s diet; however, the injected pigs had significantly higher hemoglobin values than noninjected pigs. There was no significant difference in weight gains of pigs due to the sow’s diet or to iron dextran injections at 21 or 24 days, when the iron injections were given at 7 and 10 days of age, respectively. Copyright © 1965 American Society of Animal Science. Used by permission. EFFECT OF FERROUS FUMARATE IN THE LACTATION DIET ON SOW MILK IRON, PIG HEMOGLOBIN AND WEIGHT GAIN 1 T. L. VEuM, J. T. GALLO, W. G. POND, L. D. VAN VLECK AND J . K. LoosLI Cornell University, Ithaca, New York M cGOWAN and Crichton (1924) reported that the addition of ferric oxide to the diet of lactating sows prevented anemia in suckling pigs. They suggested that the pigs obtained iron from the sow's feed and feces rather than from any increase in the iron content of the milk. Elvehjem et al. (1927) found the iron content of goat's milk was not increased by feeding either ferric oxide or ferrous sulfate. Har t et al. (1929), Hamilton et al. (1930) and Venn et al. (1947) also failed to demonstrate increased iron levels in sow's milk from the addition of iron salts to the diet. Pond et al. (1961) reported that intramuscular injection of iron into the sow during gestation or lactation did not increase placental or mammary transfer of iron. Chancy and Barnhart (1963) and Hansard et al. (1964) indicated that the iron content of the sow's milk could be increased to levels sufficient to prevent baby pig anemia by adding ferrous fumarate to the lactation diet. Catron et al. (1963) also found that ferrous fumarate aided in the prevention of baby pig anemia when fed to lactating sows. Other data presented by Hooks et al. (1963) and Miller et al. (1964) have not confirmed this response with ferrous fumarate. This suggests that the observed increase in hemoglobin may be the result of pigs' obtaining iron from the sow's diet and from her feces. This study was undertaken to determine the effect of ferrous fumarate supplementation of the diet fed the lactating sow on milk iron content and on weight gains and hemoglobin levels of the suckling pigs. Experimental Procedure Experiment I. Ten Yorkshire sows were randomly allotted at farrowing to either a basal diet or the basal supplemented with 1984 nag. of elemental iron as ferrous fumarate per kilogram of diet. Composition of the basal diet in percent was as follows: yellow corn (No. 2), 73.0; dehydrated alfalfa meal, 10.0; meat scraps, 6.0; soybean meal, 10.0; 1 Supported in Dart by Walnut Grove Products Company, Inc., Atlantic, Iowa. trace mineralized salt, 0.5; dicalcium phosphate, 0.3; and vitamin supplement, 2 0.25. By analysis the diet contained 13.3~o protein and 1896 and 157 rag. of iron per kilogram of diet with and without supplementation, respectively. The sows were kept in concretefloored pens with their litters during the 24day study, and the pens were cleaned once daily. The pigs were not given creep feed while the sows were fed ad libitum. One-third to one-half of the pigs in each litter were injected intramuscularly with 150 rag. of iron as iron dextran 3 at about 10 days of age. Milk samples were obtained by machine (Hartman and Pond, 1960) on days 4, 12, 19 and 24 of the lactation period. Milk letdown was accomplished by intramuscular injection of 4 to 6 ml. of oxytocin. 4 Milking was continued until milk ceased to flow. No particular precautions were taken to standardize the length of time between milking and previous nursing. A subsample of milk was removed for iron analysis ~ using a modification of the A.O.A.C. (1960) colorimeter procedure. Blood samples were collected by punCture of the anterior vena cava, and individual body weights were recorded on the day of milking. Hemoglobin was determined by the method of Sanford and Sheard (1929). Analysis of variance (with unweighted squares of means) was conducted as described by Steel and Torrie (1960). The sow mean square was used for testing differences between treatments. The error mean square (pigs within sows) was used for testing differences among sows. Experiment II. Since iron content of the milk was not increased by supplementing the sow diet with ferrous fumarate in Experiment I, this experiment was conducted to determine whether or not the hemoglobin increase observed at 24 days in Experiment I in pigs nursing sows fed ferrous fumarate was due to Hopro R, Borden Company, New York, N. Y. s Armour Pharmaceutical Company, Kankakee, Illinois, ~upplied the Armldexan. Armour Pharmaceutical Company, Kankakee, Illinois, oxytoeln injection 20 U.S.P. units per ml. Walnut Gro'~e Products Company, Inc., Atlantic. Io,~a, supplied the feed grade ferrous fumarate and analyzed the milk samples for total iron at their chemical laboratory.