Potential and Metabolic Impacts of Double Enrichments of Docosahexaenoic Acid and 25-Hydroxy Vitamin D in Tissues of Broiler Chickens.

Background: Chicken may be enriched with 25-hydroxy D [25(OH)D] and docosahexaenoic acid (DHA) to enhance the dietary intake of the public.

Objectives: Two experiments (Expt.) were conducted to determine the potential and metabolic impacts of enriching both DHA and 25(OH)D in the tissues of broiler chickens.

Methods: In Expt. 1, 144 chicks (6 cages/treatment and 6 birds/cage) were fed a corn-soybean meal basal diet (BD), BD + 10,000 IU 25(OH)D/kg [BD + 25(OH)D], BD + 1% DHA-rich Aurantiochytrium (1.2 g DHA/kg; BD + DHA), or BD + 25(OH)D+DHA for 6 wk. In Expt. 2, 180 chicks were fed the BD, BD + DHA-rich microalgal oil (1.5-3.0 g DHA/kg, BD + DHA), BD + DHA + eicosapentaenoic acid (EPA)-rich microalgae (0.3-0.6 g EPA/kg, BD + DHA + EPA), BD + DHA + 25(OH)D [6000 to 12,000 IU/kg diet; BD + DHA + 25(OH)D], and BD + DHA + EPA + 25(OH)D for 6 wk.

Results: Supranutrition of these 2 nutrients resulted in 57-62 mg DHA and 1.9-3.3 μg of 25(OH)D/100 g of breast or thigh muscles. The DHA enrichment was independent of dietary EPA or 25(OH)D, but that of 25(OH)D in the liver was decreased (68%, P < 0.05) by dietary DHA in Expt. 1. Compared with BD, BD + 25(OH)D enhanced (P < 0.05) gene expression related to D absorption (scavenger receptor class B type 1 and Niemann-pick c1 like 1) in the liver and D degradation (cytochrome P450 24A1) in the breast, and decreased mRNA or protein concentrations of vitamin D binding protein in the adipose tissue or thigh muscle. Supranutrition of DHA decreased mRNA concentrations of lipid metabolism-related genes (fatty acid desaturase 1,2, ELOVL fatty acid elongase 5, fatty acid desaturase 2, fatty acid synthase, and sterol regulatory element-binding protein 1).

Conclusions: Both DHA and 25(OH)D were enriched in the muscles up to meeting 50%-100% of the suggested intakes of these nutrients by consuming 2 servings of 100 g of fortified chicken. The enrichments altered gene expression related to lipid biosynthesis and vitamin D transport or storage.