TY - JOUR
T1 - Growth performance, bioavailability of toxic and essential elements and nutrients, and biofortification of iodine of rainbow trout (Onchorynchus mykiss) fed blends with sugar kelp (Saccharina latissima)
AU - Granby, Kit
AU - Amlund, Heidi
AU - Valente, Luísa M. P.
AU - Dias, Jorge
AU - Adoff, Grethe
AU - Sousa, Vera
AU - Marques, António
AU - Sloth, Jens Jørgen
AU - Larsen, Bodil Katrine
PY - 2020
Y1 - 2020
N2 - Aquaculture production is demanding novel feed ingredients that reflect natural marine nutrient levels, that are also essential to humans. In this regard, biofortification through addition of iodine-rich sugar kelp in feed formulations was assessed in a 12 week rainbow trout trial. Yttrium inclusion in feed allowed determinations of apparent absorption coefficients of essential and potentially toxic elements and apparent digestibility coefficient of nutrients. E.g. apparent absorption coefficients in trouts fortified feed with 1–4% dw kelp were 67–61% As, 32–40% Cd, <5% Fe; 80–83% I; 66-58% Se. Iodine concentrations in feed up to 239 mg/kg (∼4% kelp) was proportional to iodine accumulation in trout fillets (R2 = 1.00) with 0.5% transfer ratio. Feed iodine concentrations up to 117 mg/kg (∼2% kelp) did not affect growth performance negatively, but increased significantly protein efficiency ratio after eight weeks feeding. However, 4% kelp meal inclusion affected final growth and hepato somatic index, and caused histomorphological changes in the intestine. All fillets had low toxic element concentrations (As, Cd, Hg, Pb). The potential applicability of Saccharina latissima as feed ingredient to tailor iodine concentration in farmed fish is evident. Consuming of a 160 g fillet (2% kelp) contributes ∼60% of recommended daily iodine intake for adults.
AB - Aquaculture production is demanding novel feed ingredients that reflect natural marine nutrient levels, that are also essential to humans. In this regard, biofortification through addition of iodine-rich sugar kelp in feed formulations was assessed in a 12 week rainbow trout trial. Yttrium inclusion in feed allowed determinations of apparent absorption coefficients of essential and potentially toxic elements and apparent digestibility coefficient of nutrients. E.g. apparent absorption coefficients in trouts fortified feed with 1–4% dw kelp were 67–61% As, 32–40% Cd, <5% Fe; 80–83% I; 66-58% Se. Iodine concentrations in feed up to 239 mg/kg (∼4% kelp) was proportional to iodine accumulation in trout fillets (R2 = 1.00) with 0.5% transfer ratio. Feed iodine concentrations up to 117 mg/kg (∼2% kelp) did not affect growth performance negatively, but increased significantly protein efficiency ratio after eight weeks feeding. However, 4% kelp meal inclusion affected final growth and hepato somatic index, and caused histomorphological changes in the intestine. All fillets had low toxic element concentrations (As, Cd, Hg, Pb). The potential applicability of Saccharina latissima as feed ingredient to tailor iodine concentration in farmed fish is evident. Consuming of a 160 g fillet (2% kelp) contributes ∼60% of recommended daily iodine intake for adults.
KW - Iodine biofortification
KW - Macroalgae
KW - Rainbow trout
KW - Digestibility
KW - Apparent absorption coefficient
KW - Arsenic
U2 - 10.1016/j.fct.2020.111387
DO - 10.1016/j.fct.2020.111387
M3 - Journal article
C2 - 32360216
VL - 141
JO - Food and Chemical Toxicology
JF - Food and Chemical Toxicology
SN - 0278-6915
M1 - 111387
ER -