The effects of iron supplementation in preweaning piglets.

The trial was carried out at a commercial pig farm in Bukit Pelanduk, Negeri Sembilan, Malaysia. The objective of the study was to assess the efficacy of supplemental iron in drinking water and iron in paste form in comparison with the iron dextran injection. A total of 12 litters were used divided into three treatments : iron dextran injection (ID), Fedexx" - iron in paste form (IP) and Opti-iron" - iron in drinking water (IW). Hemoglobin level and growth performance parameters were monitored weekly over a period of 28 days. ID piglets had significantly higher (p < 0.05) body weight and weekly weight gain compared with IW piglets at 21 and 28 days of age whereas no significant different (p > 0.05) results were found between IP and IW piglets. Hemoglobin level from days 0 to 28 showed statistical difference (p > 0.05) between piglets in IP and IW groups. Mild anemia was found in IP piglets but not for ID and IW piglets compared with normal value (> 9 g/dL). Hemoglobin (Hb) levels were positively correlated (p < 0.05, r = .47) with body weight at 28 days of age. In conclusion, pigs supplemented with iron in paste form and drinking water had poorer growth performance than iron dextran injection piglets. Piglets given iron in paste form had mild anemia. It is advisable to give multiple doses of oral iron to piglets in order to prevent iron deficiency anemia. During the first 4 weeks of life, the body weights of the piglets increased by up to 5-fold. The dietary requirement for iron during this period is 7 mg per day but only 1 mg per day can be supplied by the sow's milk (Cunha, 1977; Miller and Ullrey, 1997; Roberts, 1998). The need to provide the piglets with an adequate amount of iron before weaning is therefore imperative because sow's milk alone will not meet the iron requirements of rapid growth and expanding blood volume (Hannan, 1971). Several different methods can be used to offer iron to preweaning piglets. The most common administration method for iron in piglets is through an intramuscular injection of iron dextran complex at 3 days of age. A single dose of 200 mg/ml iron-dextran is effective against iron deficiency anemia. However, the method is very stressful to the piglets. They will suffer more pain if a greater dosage of iron is given intramuscularly. Furthermore, poor iron injection techniques may cause considerable trauma to the muscles, staining of hams or create abscesses and lead to downgrading of the carcasses (Roberts, 1998). Since there are several drawbacks to the iron injection, alternative methods need to be considered in intensive farming i.e. supply iron orally (Miller and Ullrey, 1997). The oral administration of iron has two advantages: cost and the fact that absorption is regulated by the intestinal mucosae. However, oral administration requires multiple doses. This is because a single dose may not be sufficient to protect the piglets from iron deficiency anemia for the first 4 weeks post-partum. The iron bioavailability in oral iron depends greatly on iron status of animals (Amine et al., 1972; Susan and Wright, 1985). In addition, dietary factors such as amino acids and protein sources (Martinez et al., 1981), pectin content, phytate (Morris and Ellis, 1982) and the other minerals (Elvehjem and Hart, 1932; Hedges and Kornegay, 1973; Suttle and Mills, 1966) may also influence the bioavailability of iron. Oral iron can be given as paste or drinking water. Early administration of oral iron within the first few days of life will meet the iron needs of the suckling pig. However, it is critical to administer early before gut closure to large molecules (Harmon et al., 1974; Thoren-Tolling, 1975). This study was conducted to determine the efficacy of iron supplementation in drinking water or paste form in comparison with the injection of iron compounds in suckling pigs.