|Carroll, Jeffery - Jeff Carroll|
Submitted to: Domestic Animal Endocrinology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2003
Publication Date: 5/1/2003
Citation: CARROLL, J.A., GAINES, A.M., SPENCER, J.D., ALLEE, G.L., KATTESH, H.G., ZANNELLI, M.E. EFFECT OF MENHADEN FISH OIL SUPPLEMENTATION AND LIPOPOLYSACCHARIDE EXPOSURE ON NURSERY PIGS: I. EFFECTS ON THE IMMUNE AXIS WHEN FED DIETS CONTAINING SPRAY-DRIED PLASMA. DOMESTIC ANIMAL ENDOCRINOLOGY. 2003. v. 24. p. 341-351.
Interpretive Summary: The objective of the present study was to evaluate the potential immunological benefit of adding menhaden fish oil to the diet of weaned pigs. For this study, we utilized 24 pigs which were weaned at 18 days of age into a research facility. Pigs were fed a complex nursery diet containing 30% lactose and 7% plasma protein with 6% corn oil as the fat source or with 5% menhaden fish oil and 1% corn oil as the fat source for a period of 15 days. After this 15 day period, we exposed the pigs to an immune challenge and measured hormone and cytokine concentrations in the blood which were associated with an immune response. The data indicated that feeding menhaden fish oil to young pigs reduced hormone and cytokine concentrations in the blood following the endotoxic challenge. While further studies are needed to evaluate the immunologically beneficial effect of including menhaden fish oil in the nursery pig diet, the present study demonstrated that supplementation with fish oil alters the immunological response to an lipopolysaccharide challenge. Given that feeding sub-therapeutic levels of antibiotics has become a much debated topic, information regarding the use of nutritional supplements to boost immune function will be of importance to all livestock production in the United States, as well as in other countries. This data will also be of interest to all individuals associated with swine production including scientists in academia, government, and industry.
Technical Abstract: The objective of the present study was to evaluate the potential immunological benefit of adding menhaden fish oil to the diet of weaned pigs. Twenty-four crossbred male pigs were weaned at 18.7 +/- 0.13 days of age and placed on a complex nursery diet containing 30% lactose and 7% plasma protein with 6% corn oil as the fat source (Cont, n=12) or with 5% menhaden fish oil and 1% corn oil as the fat source (MFO, n=12) for a period of 15 d. Body weights did not differ (P > 0.78) between dietary groups either at the beginning or end of the 15d-feeding period. On d15, all pigs were non-surgically fitted with an indwelling jugular catheter. On d16, pigs received an i.v. injection of either saline (n=6/dietary group) or lipopolysaccharide (LPS; 150 ug/kg body weight; n=6/dietary group) and blood samples were collected at 30-min intervals for a period of 5h. Serum was harvested and stored at -80°C for analysis of cortisol (CS), corticosteroid-binding globulin (CBG), tumor necrosis factor-alpha (TNF) and interferon-gamma (IFN). There was no significant effect of diet on basal concentrations (Time 0) of any of the blood parameters analyzed. A Time × Treatment × Diet interaction (P = 0.023) was observed for serum CS such that those pigs which consumed the MFO diet followed by LPS treatment had a reduced CS response as compared to the LPS treated pigs on the Cont diet. A Time × Treatment interaction (P = 0.0048) was observed for serum CBG such that LPS treatment reduced circulating CBG as compared to the saline treated pigs. Time × Treatment × Diet interactions were also observed for serum concentrations of TNF (P = 0.084) and IFN (P = 0.022) such that both the TNF and IFN response to the LPS challenge was lower in those pigs receiving the MFO diet as compared to the LPS treated pigs on the Cont diet. Overall, serum CS was negatively correlated with the CBG response (r = -0.40, P < 0.001), however, the strongest negative correlation was observed in the LPS treated pigs which consumed the MFO diet (r = -0.63, P < 0.001). While further studies are needed to evaluate the immunologically beneficial effect of including menhaden fish oil in the nursery pig diet, the present study demonstrates that supplementation with fish oil alters the immunological response to an LPS challenge.