There’s no question that newborn piglets are more susceptible to iron deficiency due to inadequate iron stores at birth and rapid growth rate before weaning. But little research exists on just how much iron is needed and the best time to administer iron injections.
Research at Kansas State University took a deeper dive into this subject in an attempt to build the amount of information available on this important topic, said Joel DeRouchey, professor of swine nutrition and management at Kansas State University, during a SowBridge seminar hosted by the Iowa Pork Industry Center on Wednesday.
What is the ideal dosage of iron for piglets?
The researchers evaluated the effects of increasing the dosage of iron in newborn piglets on suckling and subsequent nursery performance and iron status on 336 newborn pigs utilizing DNA genetics. A total of 28 litters were evaluated over a 63-day study.
On the day of processing, approximately three days after farrowing, six barrows and six gilts within each litter were allotted to one of six treatments including a negative control with no iron injection, and GleptoForte™ iron injections at 50 mg, 100 mg, 150 mg, 200 mg and a 200 mg + 100 mg booster at day 11 post-birth.
Weights and blood samples were evaluated throughout the study. Hayden Williams, a Ph.D. graduate student who led this research, said from birth until weaning, the 100 mg injection of iron maximized growth performance, but the 200 mg iron injection provided the greatest iron blood status for the pig when entering the nursery.
During the nursery phase, the 200 mg iron injection maximized growth performance and blood status, Williams said. Little difference was observed between doses of 150 mg and 200 mg.
The researchers also discovered that the 100 mg booster did not provide a growth performance benefit in either farrowing or nursery, but did result in greater hemoglobin, Hct and serum iron at weaning as compared to the 200 mg injection alone.
Feeding nursery diets that included 110 ppm of added iron sulfate restored blood iron status in the pigs that received no or low levels of injected iron at processing by the end of the nursery period.
“But the poor growth performance couldn’t be compensated,” DeRouchey said. “We didn’t capture that back by feeding nursery diets with iron sulfate.”
When is the best time to give iron injections?
Most producers give iron injections ranging from 2 to 6 days after birth. Researchers decided to evaluate the effects of iron injection timing after birth in newborn piglets on suckling and subsequent nursery performance iron status.
The team evaluated 324 newborn, DNA-sired pigs in 27 litters. Two days after birth, six barrows and six gilts within each litter were allotted to one of six treatments in a completely randomized design. Treatments were arranged with increasing age of newborn pigs each receiving a single, 200-mg injection of GleptoForte™ iron.
One group received no iron, the other five groups received the iron at 2, 4, 6, 8 and 10 days after birth. Pigs were weighed and blood samples were evaluated.
From birth until weaning, the 200 mg iron injection provided the greatest growth performance on day four and day six, Williams said. The greatest blood iron status was realized on day six.
During the nursery phase, Williams noted that the 200 mg iron injection on day four or day six provided the greatest body weight at the end of the nursery phase. They did not find any evidence of difference in blood iron status in the nursery.
What does the research recommend?
The 200 mg injection of iron provided the best growth response, DeRouchey said. He noted that they did not test levels above 200 mg, however he is confident that 200 mg is an adequate level to get optimal results given the booster injection provided no further benefit, but more research should be done to confirm this finding.
“Some pigs receive iron earlier in life, but it’s important to review your SOPs and protocols,” he said. “We need to minimize how many pigs get iron too soon after birth. Based on the data, we give up growth performance by giving them iron too soon. The research shows days four and six are an optimal time to give your piglets the iron they need.”
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