Range on vitamin and mineral contents and proximate composition of commercial tilapia feeds in Brazil

Abstract

The number of feed mills manufacturing aquafeeds has increased considerably, and as a consequence so has the range of quality commercial fish feeds. A better knowledge of the actual composition of feeds available in the Brazilian market is key to meet the main challenges currently come across by fish farmers: hampered growth rate and increased incidence of diseases of stocked fish. Mineral and vitamin contents, proximal composition, in vitro pepsin digestibility and peroxide values were thus determined in 15 commercial tilapia Oreochromis spp. feeds (32% protein contents, grower phase) marketed in Brazil from 2017 to 2020 with the aid of atomic spectrometry and HPLC techniques. A broad range of mineral and vitamin contents were registered among the samples and also in comparison to recommended values in specialized literature. Particularly, all diets registered excessive amounts of trace mineral elements as Fe that registered up to 13 times the recommended requirement and also Cu (up to 43.35 mg/kg) and Mn (up to 114.28 mg/kg). The vitamin A (mean value registered 2538.55 IU/kg) were lower than the recommended requirement in 13 out of the 15 sampled commercial feeds. The highest peroxide values of feeds were associated with low pepsin digestibility. The results were discussed in the context of available information on the dietary mineral and vitamin requirements for tilapia Oreochromis spp.

Keywords

• oreochromis spp.
• nutritional requirements
• atomic spectrometry
• hplc
• omnivorous fish