Supranutrition of microalgal docosahexaenoic acid and calcidiol improved growth performance, tissue lipid profiles, and tibia characteristics of broiler chickens

Abstract

Abstract Background: Enriching chicken with docosahexaenoic acid (DHA) and calcidiol may be used to improve public nutrition and health. It remains unclear if superanutritional levels of DHA and calcidiol impair growth or metabolism of broiler chickens. The aim of the study was to determine singular and combined effects of high levels of supplemental DHA-rich microalgal biomass or oil and calcidiol on growth performance, plasma and tissue lipid profiles, and bone characteristics of broiler chickens. Methods: In Experiment 1, 144 day-old Cornish chicks were divided into 4 groups (6 cages/treatment, 6 birds/cage), and were fed a corn-soybean meal basal diet (BD), BD + 10000 IU calcidiol/kg (BD+Cal), BD + 1% DHA-rich Aurantiochytrium(1.2 g DHA/kg; BD+DHA), and BD+Cal+DHA for 6 wk. In Experiment 2, 180 day-old chicks were divided into 5 groups (6 cages/treatment, 6 birds/cage), and were fed: BD, BD+ DHA (oil, 1.5 to 3.0 g DHA/kg), BD + DHA + EPA (eicosapentaenoic acid, 0.3 to 0.6 g/kg), BD+DHA+ calcidiol (6,000 to 12000 IU/kg diet), and BD+DHA+EPA+Cal for 6 wk. Growth performance, concentrations of triglyceride, cholesterol, and nonesterifed fatty acids in plasma, liver, breast, and thigh, and biophysical properties of tibia were determined. Results: Birds fed BD+Cal diet in Experiment 1 and BD+DHA+EPA diet in Experiment 2 had higher (P < 0.05 body weight gain (10-11%) and gain: feed ratio (7%), and lower (P < 0.05) total cholesterol and triglyceride concentrations in plasma (18-54%), liver (8-26%), breast (19-26%), and thigh (10-19%), respectively, over the controls. The two diets also improved (P < 0.05) tibial breaking strength (8-24%), total bone volume (2-13%), and(or) bone mineral density (3-19%) of chickens. Conclusion: Superanutrition of dietary calcidiol and DHA alone or together did not produce adverse effects, but improved growth performance, lipid profiles of plasma and muscle, and bone health of broiler chickens.