The use of vegetable ingredients may alter the mineral balance of fish feed due to the differences in mineral composition between marine and vegetable ingredients.
Researchers from the University of Las Palmas, together with BioMar, evaluated the effect of zinc and manganese in gilthead sea bream (Sparus aurata) fingerlings. Vegetable, meal and oil, based diets were formulated including the target minerals, zinc and manganese, in two different delivery forms, oxides and chelated to amino acids. Five different diets containing either non-mineral supplementation, zinc and manganese oxides, amino acid chelates and their combinations were tested on 8.2 g gilthead sea bream.
The results showed that fish fed with zinc oxide supplementation presented higher growth, higher deposition of protein and lower lipid content in the whole body, but there was an increase in whole body TBARs and up-regulation of CuZnsod in fish fed on diets supplemented with amino acids chelated Zn.
This study aimed to overcome the shortcomings of other studies regarding mineral-specific effects in Sparus aurata. Zinc oxide supplementation may improve fish performance, but the effects were not clear for the manganese sources.
Read full study here.