|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: GAINES, A.M., CARROLL, J.A., YI, G., ALLEE, G.L., ZANNELLI, M.E. EFFECT OF MENHADEN FISH OIL SUPPLEMENTATION AND LIPOPOLYSACCHARIDE EXPOSURE ON NURSERY PIGS: II. EFFECTS ON THE IMMUNE AXIS WHEN FED SIMPLE OR COMPLEX DIETS CONTAINING NO SPRAY-DRIED PLASMA. DOMESTIC ANIMAL ENDOCRINOLOGY. 2003. v. 24. p. 353-365. Interpretive Summary: The overall objective of this research was to determine the effects of menhaden fish oil supplementation and diet complexity on the performance and immune response of young pigs. For this study, we placed 17-day-old pigs into a segregated early wean facility and provided free access to a complex diet for 7 days. After the first 7 days, pigs were placed on a simple or complex diet with or without menhaden fish-oil supplementation. Fourteen days later, we conducted an immune challenge on the pigs using an endotoxin. We examined hormones and cytokines associated with the immune response, as well as growth performance following the immune challenge. Results indicated that supplementing the young pig's diet with fish oil lessened the immune response to the endotoxin challenge. However, this beneficial effect was only observed for fish-oil-supplemented pigs which were being fed a complex diet. Therefore it appears that diet complexity may determine the immunologically beneficial effects of dietary supplements such as menhaden fish oil. 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: A trial using 64 weanling pigs (TR4 x PIC C22) was conducted to determine the effects of menhaden fish-oil supplementation and diet complexity on performance and immune response of nursery pigs. Pigs (17 d and 6.27 +/- 1.16 kg) were weaned into a segregated early wean facility and given free access to a complex diet for 7 days postweaning. At d0 (d7 postweaning), pigs were blocked by weight and allotted to 64 pens. Treatments (Trt) were arranged as a 2×2×2 factorial experiment. Main effects included diet (complex vs. simple), oil (menhaden fish (MFO) vs. corn (CO)), and immunogen (saline vs. lipopolysaccharide (LPS)). Experimental diets contained 6% oil (6% CO or 5% MFO + 1% CO) and were fed for 14 days. On d12, i.v. injections of either LPS (150 ug/kg) or saline were given, followed by blood collection at 30 min intervals for 6 hrs. After the immune challenge (d14), pigs were placed onto a common corn-soybean meal fortified diet and growth performance was evaluated until termination of the study (d28). Pigs were weighed and feed intakes recorded at 7, 14, and 28d. Prior to immune challenge (d12), there were differences in body weight for pigs fed complex vs. simple diets (P < 0.01; 13.1 and 12.1 kg, respectively) and pigs fed CO vs. MFO diets (P < 0.05; 12.9 and 12.3 kg, respectively.) During the challenge period, for pigs treated with LPS there was a Time × Immunogen × Oil effect (P < 0.001) for serum cortisol with MFO fed pigs having lower serum cortisol as compared to CO fed pigs. Also, during the challenge period, for pigs treated with LPS, there was a Time × Diet × Immunogen × Oil effect (P < 0.001) for serum tumor necrosis factor-alpha (TNF) with pigs fed complex diets supplemented with CO having higher serum TNF as compared with pigs fed complex diets supplemented with MFO. At d14 and 28, LPS-treated pigs had lower body weight than saline-injected controls (P < 0.001 and 0.01, respectively.) In addition, pigs fed simplified diets continued to have lower body weight after challenge compared to pigs fed a complex diet. Interestingly, there were no differences (P > 0.10) in body weight after challenge in pigs fed MFO. This study suggests that MFO supplementation may provide immunological protection during LPS challenge and that simplified diets may compromise nursery performance.