Abstract
Newborn pigs (n = 336; 1.7 kg BW) were used in a 21-d study evaluating the effects of increasing injectable Fe on preweaning pig performance and blood Fe status. A total of 28 litters were used and at processing (d 3 after farrowing) all piglets were weighed and six barrows and six gilts/litter were allotted to 1 of 6 treatments in a CRD. Treatments consisted of a negative control receiving no Fe injection and increasing injectable Fe (Gleptoforte, Ceva Animal Health, Lenexa, KS) to achieve 50, 100, 150, 200-mg, or 200-mg plus a 100-mg injection on d 11 post-farrowing. Piglets were weighed and bled on d 3, 11, and 21 of age to determine growth performance and blood Fe status. Preweaned pig growth data and hematological criteria were evaluated using individual pig as the experimental unit with hematological criteria analyzed as a repeated measure. Increasing injectable Fe up to 100-mg improved (quadratic; P < 0.05) ADG and d 21 BW with no further improvement thereafter (Table 1).There were no evidence of differences (P > 0.10) between the 200-mg and 200 + 100-mg treatments for growth. Significant treatment×day interactions (P < 0.001) were observed for hemoglobin (Hgb) and hematocrit (Hct). The interactions were the result of decreased values for pigs receiving no Fe injection or an Fe injection of 100-mg or less, while pigs receiving an Fe injection greater than 100-mg had increased values at d 21. Pigs receiving the 200 + 100-mg treatment had increased (P < 0.05) Hgb and Hct values compared to pigs receiving a single 200-mg Fe injection on d 21. Results suggest that a 100-mg Fe injection is sufficient for growth performance during the preweaning phase, but an Fe injection greater than 100-mg is needed to maximize blood criteria. An extra 100-mg Fe injection at d 11 did not influence growth performance but does increase Hgb and Hct at weaning.
