Prophylactic enrichment of enterocyte phospholipids with polyunsaturated fatty acids fed to suckling piglets

Abstract

HESS, HOLLY ALINE. Prophylactic enrichment of enterocyte phospholipids with polyunsaturated fatty acids fed to suckling piglets. (Under the direction of Dr. Jack Odle and Dr. Robert J. Harrell.) Infant formula companies began fortifying formulas with long-chain polyunsaturated fatty acids (PUFA) in 2002, including arachidonic acid (AA) at ~ 0.5% of total fatty acids. This study is the first in a series that will examine effects of supra-physiological supplementation of AA on intestinal health. The objective was to determine the time specific effects of dietary AA on fatty acid composition of enterocyte phospholipids and on the mRNA abundance of hepatic ∆ 6 -and ∆ 5 desaturases. One d old pigs (N=96) were fed a milk-based formula for 4, 8, or 16 d. Diets contained either no PUFA (0%AA, negative control), 0.5%AA, 2.5%AA, 5%AA, or 5% eicosapentaenoic acid (EPA) of total fatty acids. Growth (299 +/-21 g/d) was unaffected by treatment (P>0.1). By day 16, ileal enterocyte phospholipid concentrations of AA were enriched 176%, 280%, and 355% in pigs fed the 0.5%AA, 2.5%AA, and 5%AA diets, respectively, compared with the 0%AA control (P<0.05). Concentration of AA within enterocytes of the 5% EPA fed group was similar to that of the 0%AA fed pigs, while EPA concentration increased by >8 fold. As pigs aged from birth to 16 d of age, there were no differences in the desaturase mRNA abundance (P>0.1), measured in pigs fed 0.5% or 5%AA. Abundance also was similar among AA-supplemented pigs, but was elevated by 60-80% in the 0%AA-fed pigs compared to those fed 2.5% (P<0.05). These data demonstrate a dose-dependent response in enterocyte AA concentration to dietary AA and show that supra-physiologic supplementation of AA is not detrimental to growth or desaturase gene expression.