Research has shown the clear production impacts of hemoglobin levels in sows and piglets. Low hemoglobin is documented to result in increased farrowing duration, stillbirths and mummies in sows as well as reduced post-weaning growth rates in piglets.
“Very little research has focused on hemoglobin levels in boars,” says Seth Reicks, a veterinary student at the University of Minnesota College of Veterinary Medicine. “We wanted to define normal hemoglobin distributions in boars and explore how hemoglobin might be associated with reproductive parameters.”
Does hemoglobin in boars impact libido and sperm production? Reicks says their ultimate goal was to identify ways to increase boar stud efficiency and profitability for producers.
Collecting the Data
Reicks visited multiple commercial boar studs across the Midwest to collect blood samples from 246 boars representing seven breed lines, including Landrace, Large White, Danish Landrace, Meishan and two Duroc lines. He also measured hemoglobin concentrations using HemoCue analyzers.
“We first established a distribution of hemoglobin levels across the population,” he explained at the Allen D. Leman Swine Conference. “Then, in our ‘Why Hemoglobin Matters in Boars’ study, we evaluated relationships between hemoglobin and key reproductive performance indicators, specifically semen production parameters (such as total sperm output and sperm morphology) and boar libido scores.”
Hemoglobin and Libido
Reicks says the most important takeaway was that boars with higher hemoglobin levels demonstrated higher libido.
“Interestingly, hemoglobin levels were not associated with semen quality or quantity, suggesting that hemoglobin influences behavioral, rather than physiological, aspects of reproductive performance,” he adds.
This study provides practical applications for improving boar stud efficiency and profitability. Reicks encourages boar studs to incorporate hemoglobin testing into routine health assessments, consider iron injection interventions for low hemoglobin boars, and reevaluate boars with mounting difficulties by looking at their hemoglobin levels.
“Boars with higher libido require less time, energy and labor to mount artificial insemination dummies, which reduces handling time and improves overall collection throughput,” Reicks says. “Additionally, identifying and supporting boars with adequate hemoglobin levels could help reduce cull rates for poor libido, since boars that fail to mount cannot contribute to semen production, representing a financial loss for studs.”
He believes improving libido through hemoglobin management could enhance both animal welfare and economic outcomes for producers.
In the future, he believes further research should take a deeper look to determine if libido problems can be corrected with injectable iron supplementation.
Collaborators in this study include Darwin Reicks and Megan Hood of Reicks Veterinary Research and Consulting; and Chris Olson and Wesley Lyons of Pharmacosmos.
