PSVI-19 Evaluating the effects of day of iron injection after farrowing on nursery performance and hematological criteria

Weaned pigs (n = 311; 5.9 kg BW) were used in a 59-d study evaluating the effects of Fe injection timing after birth on nursery pig performance and hematological criteria. Pigs were weaned at 21 d and allotted to pens based on preweaning Fe treatment with BW balanced across pens within a treatment with 5 or 6 pigs/pen and 10 pens/treatment. The preweaning treatments were a negative control receiving no Fe injection or 200-mg of injectable Fe (Gleptoforte, Ceva Animal Health, Lenexa, KS) provided in a single injection on d 2, 4, 6, 8, or 10 after birth. All pigs were fed common diets after weaning that contained 110 mg/kg of added Fe as FeSO4 provided from the trace mineral premix. Growth data were analyzed as a completely randomized design with pen as the experimental unit. Hematological criteria were measured as a repeated measure with pig as the experimental unit. Overall, increasing the age of pigs receiving a 200-mg Fe injection from 2 to 4 or 6 d after birth increased (quadratic; P = 0.013) d 80 ending BW with a decrease in BW when Fe was provided on d 8 or 10 (Table 1). Not providing an Fe injection after birth worsened (P < 0.05) ADG, ADFI, and d 80 ending BW. Significant treatment×day interactions (P < 0.001) were observed for Hgb and Hct values. These interactions occurred because pigs not receiving an Fe injection after birth had values that increased from d 21 to 35 while pigs receiving an Fe injection had values that decreased from d 21 to 35. While it is common practice to provide an Fe injection within the first 48 hours of birth, these results suggest delaying injection until d 4 or 6 may increase nursery final weight.