Effects of increasing Fe dosage in newborn pigs on suckling and subsequent nursery performance and hematological and immunological criteria.

Williams, Hayden E; DeRouchey, Joel M; Woodworth, Jason C; Dritz, Steven S; Tokach, Michael D; Goodband, Robert D; Holtcamp, Andrew J; Bortoluzzi, Eduarda M; Gebhardt, Jordan T

A total of 336 newborn pigs (DNA 241 × 600, initially 1.75 ± 0.05 kg bodyweight [BW]) from 28 litters were used in a 63-d study evaluating the effects of increasing injectable Fe dose on suckling and subsequent nursery pig performance and blood Fe status. GleptoForte (Ceva Animal Health, LLC., Lenexa, KS) contains gleptoferron which is a Fe macro-molecule complex that is commercially used as an injectable Fe source for suckling piglets. On the day of processing (d 3 after birth), all piglets were weighed and six barrows and six gilts per litter were allotted within sex to 1 of 6 treatments in a completely randomized design. Treatments consisted of a negative control receiving no Fe injection and increasing injectable Fe to achieve either 50, 100, 150, 200 mg, or 200 mg plus a 100 mg injection on d 11 after birth. Pigs were weaned (~21 d of age) and allotted to nursery pens based on BW and corresponding treatment in a completely randomized design. During lactation, increasing injectable Fe up to 100 mg improved (quadratic; P < 0.05) average daily gain (ADG) and d 21 BW with no further improvement thereafter. There was no evidence of differences (P > 0.10) observed between the 200 mg and 200 mg + 100 mg treatments for growth. For the nursery period, increasing Fe dosage increased (linear; P < 0.05) ADG, average daily feed intake (ADFI), and d 42 BW. There was no evidence of differences (P > 0.10) between the 200 mg and 200 mg + 100 mg treatments for nursery growth. For blood criteria, significant treatment × day interactions (P = 0.001) were observed for hemoglobin (Hb) and hematocrit (Hct). The interactions occurred because pigs that had less than 150 mg of injectable Fe had decreased values to d 21 and then increased to d 63 while pigs with 150 or 200 mg of injectable Fe had increased values to d 21 then stayed relatively constant to d 63. In summary, piglet performance during lactation was maximized at 100 mg while nursery growth performance and blood Fe status were maximized with a 200 mg Fe injection at processing. Providing an additional 100 mg of Fe on d 11 of age increased Hb, and Hct values at weaning and 14 d into the nursery but did not provide a growth performance benefit in lactation or nursery. These results indicate that providing 200 mg of injectable Fe provided from GleptoForte is sufficient to optimize lactation and subsequent nursery growth performance and blood Fe status.