Calcifediol is a safe and effective metabolite for raising vitamin D status and improving growth and feed conversion in rainbow trout

The vitamin D endocrine system is required for the transcriptional regulation of a myriad vertebrate genes including those involved in bone health, growth, nutrient metabolism and immunity. requirements salmonids are amongst highest any aquaculture species. With nuances, pre-vitamin cholecalciferol (D3) via calcifediol (25-OH-D3), to produce physiologically active hormone calcitriol (1,25-OH-D3) conserved fish. composition modern aquafeeds, growth seawater production challenges, such as disease, may result suboptimal biochemical activation A 91-day experimental feeding trial was used test safety efficacy supply rainbow trout with an initial body weight 57.6 g. practical diet containing within recommended levels (5240 IU) supplemented either 69.8, 687 or 6854 μg/kg calcifediol. determined by assessment zootechnical performance appearance metabolites blood. dietary interventions assessed from generic health indices, examination gross pathologies, hematology, blood chemistry. Test fish increased at least 5.6-fold 323.5 g over period. supplementation resulted significant improvements rate feed conversion (FCR). Whilst not detectable control fish, linearly according lesser extent white muscle. increases were accompanied saturable circulating D. At end period, survival 100%, no pathologies relating diets observed, chemistry, calcium phosphorus, significantly altered. improves ensures that maximal present meet physiological demands. lack effects on tested high doses concluded be safe salmonids.