Effect of Injected and Dietary Iron in Young Pigs on Blood Hematology and Post-Natal Pig Growth Performance

September 11, 2011 — 

The relationship of injected Fe doses on blood hematology and pig growth performance during both preweaning and postweaning periods was studied. In Exp. 1, the effect of BW of 347 pigs injected with 200 mg Fe (dextran) intramuscularly (i.m.) at birth on hemoglobin (Hb]) and % hematocrit (Hct) at weaning was assessed. As BW increased there was a decline (P < 0.01) in Hb and Hct. In Exp. 2, Fe injection doses and timing of injected Fe on blood hematology and pig growth were evaluated. Injections were: 1) 200 mg Fe at birth; 2) 300 mg Fe at birth; or 3) 200 mg Fe at birth + 100 mg Fe at d 10. A total of 269 pigs were allotted within litter to 3 treatments. The 2 greater quantities of injected Fe (i.e., 300 or 200 + 100 mg Fe) had similar but greater (P < 0.05) Hb and Hct values than pigs receiving 200 mg Fe, but growth rates were similar at weaning. The effects of injecting 200 mg Fe at birth and either saline or 100 mg Fe at 10 d of age were investigated in Exp. 3. Weaned pigs of each group were fed diets with 0, 80, or 160 ppm added Fe for 35 d as a 2 x 3 factorial arrangement with 12 replicates (n = 360 pigs) in a randomized complete block design (RCB). The innate Fe contents of diets averaged 200 ppm. The greater Fe injection group (200 + 100 mg) had greater (P < 0.01) Hb and Hct values through 14 d postweaning (P < 0.05) and greater (P < 0.01) Hct values through 21 d postweaning. As dietary Fe increased, Hb was greater only at d 14 (P < 0.05 4), while Hct increased linearly to d 35 (P < 0.01) postweaning. Dietary Fe resulted in linear increases (P < 0.01) in ADG from d 21 to 35 and 0 to 35. In Exp. 4, 3 levels of dietary Fe (80, 160, and 240 mg/kg diet), 2 injected Fe treatments (200 or 300 mg Fe) at birth, and birth BW (< 1.5 or = 1.5 kg) were evaluated as a 2 x 2 x 3 factorial arrangement of treatments in a RCB design with 6 replicates (n = 280 pigs). The 300 mg Fe injection group had lower BW in both birth BW groups, with a birth BW x injected Fe interaction (P < 0.01). This resulted in the lighter birth BW pigs receiving 200 mg Fe having greater gains to 240 ppm dietary Fe, while light birth BW pigs injected with 300 mg Fe plateaued at the160 ppm Fe level. Pigs in the heavy birth BW group injected with 200 or 300 mg Fe at birth responded similarly to dietary Fe levels postweaning. These results indicate that blood Hb and Hct were affected by pig weight at weaning, but the additional 100 mg Fe i.m. at 10 d of age elevated blood hematology and that Fe injected preweaning affected initial postweaning performance.

J. S. Jolliff and D. C. Mahan; Effect of injected and dietary iron in young pigs on blood hematology and post-natal pig growth performance; J ANIM SCI August 26, 2011 jas.2010-3736.

The Ohio State University and The Ohio Agricultural Research and Development Center, Columbus 43210-1095 Published online before print August 26, 2011, doi: 10.2527/jas.2010-3736.