199 Effects of an Additional Injection of Iron Administered to Piglets on Hemoglobin Concentration, Growth Performance, and Carcass Characteristics Through Market Weight

Abstract

Abstract An experiment was conducted to evaluate the effects of an additional injection of iron dextran (Uniferon, Pharmacosmos Inc.) administered at d 6 to 8 of age. Crossbred pigs [n = 144; equal barrows and gilts; initial body weight (BW) = 2.86 ± 0.01 kg] from 21 litters were assigned to either the control (CON) or an added-injection treatment (+Fe). Pigs were paired by sex and BW within a litter and randomly assigned to the iron treatment within each pair. All pigs had received a 200 mg Fe intramuscular (IM) injection < 24 h after birth. All pigs were weaned at 22 to 24 days, housed 6 pigs/pen for a total of 12 pens/treatment, and received a common corn-soybean meal diet formulated to meet or exceed the NRC (2012) requirement estimates relative to BW until slaughter. Body weight and feed disappearance were recorded at least biweekly to determine average daily gain (ADG) and feed intake (ADFI). Hemoglobin (Hb) concentrations were measured at birth, initiation of experiment (d 6 to 8), weaning, and at the end of the nursery and finisher periods. At the time of slaughter, 1 pig/pen (n = 12 pigs/treatment) was selected and slaughtered for carcass characteristic measures. Data were subjected to ANOVA by the GLM procedure of SAS; the individual pig served as the experimental unit for BW, Hb, ADG, and carcass characteristics whereas pen served as the experimental unit for ADFI, and gain/feed ratio data. The statistical model included sex, treatment, sex × treatment, and allotment pair for Hb and ADG. There were expected sex effects for ADG but no sex × treatment interactions for any response measures. The +Fe pigs had a greater Hb at weaning (13.1 vs. 10.7 g/dL, P < 0.0001) and end of the nursery (12.1 vs. 11.7 g/dL, P = 0.01) compared with CON pigs (Table 1). During the finisher period, +Fe pigs had a greater ADG (P = 0.05) compared with CON pigs. Overall, pigs receiving the added iron injection had an ~ 4% increase in ADG (P = 0.04) from weaning to slaughter. The cumulative improvement in ADG from weaning to slaughter observed for +Fe group resulted in +Fe pigs having a heavier BW at the end of the experiment (115.77 vs. 112.79 kg; P = 0.04). Following slaughter, +Fe pigs had ~ 2.5% heavier cold carcass weight (82.99 vs. 80.93 kg; P = 0.34) and trimmed loin (10.67 vs. 9.95 kg; P = 0.04) compared with the CON pigs. In conclusion, administering an additional iron injection resulted in greater Hb at weaning and the end of the nursery as well as improved growth performance from weaning to slaughter weight and increased carcass measures at slaughter.