Poster Topical Area: Experimental Animal Nutrition

Location: Hall D

Poster Board Number: 609

E09-01 - Herring Roe Oil Alters Circulating Immune Cell Populations in a Neonatal Piglet Model

Monday, Jun 11
8:00 AM – 3:00 PM

Objectives. The objective of this study was to determine if dietary supplementation with omega-3 fatty acid DHA in the neonatal period could reduce neuroinflammation during an inflammatory immune response.

Methods. Full term (114 days), average birth weight (1.2-1.8 kg), naturally delivered piglets (N = 14) were obtained from the University of Illinois Swine Farms on postnatal day (PD) 2 and weaned onto a liquid milk replacer diet containing herring roe oil (HRO) as a source of DHA (2 g/kg diet providing 40 mg/kg body weight/d DHA) or an isocaloric control (CON). On PD14, sample collection for complete blood cell counts, cell culture, gene expression, and fatty acid analysis occurred. CD11b+ microglial cells from the brain were isolated and stimulated ex vivo with 10 ng/mL lipopolysaccharide (LPS).

Results. Piglets fed the HRO diet had a lower (p = 0.0256) white blood cell count on PD14 than CON piglets. Piglets on HRO diet also had shifted populations of neutrophils and lymphocytes, while monocyte populations were not different between groups (p = 0.16). HRO piglets had a lower number of neutrophils (p = 0.0114), a higher number of lymphocytes (p = 0.0483), and a lower neutrophil/lymphocyte ratio (NLCR; p = 0.0107). The brain tissue of piglets fed HRO contained more DHA than CON piglets (p = 0.0292). Gene expression analysis of the LPS stimulated CD11b+ cells showed no differences in the inflammatory response of the cells from HRO diet piglets versus the control diet. LPS stimulation increased gene expression of TNF, IL-6, and IL-1β (p < 0.0001). There was no effect of dietary treatment on TNF (p = 0.52), IL-6 (p = 0.84), or IL-1β (p = 0.93) gene expression. There was no effect of diet on the expression of anti-inflammatory markers IL-10 (p = 0.29) and IL1-RN (p = 0.16).

Conclusions. Based on the data above, it does not appear that twice the WHO recommended dosage of dietary DHA for infants (40 mg/kg/day) can attenuate the inflammatory response when microglia from the brain are isolated and stimulated ex vivo, however, results are pending for a mild in vivo immune stimulation. The lower NLCR of the HRO group suggests that HRO supplementation may have had a positive effect on piglet health.

Funding Source: NIH HD069899

CoAuthors: Rodney Johnson – University of Illinois at Urbana-Champaign

Megan Corbett

Veterinary Student
University of Illinois at Urbana-Champaign
Champaign, Illinois