Effects of γ-Irradiated Date (Phoenix dactylifera) Fruit on Growth, Immunological and Antioxidant Parameters of Goldfish (Carassius auratus)

Abstract

The aim of this study was to evaluate the potential effects of γ-irradiated date palm fruit (Phoenix dactylifera), which is rich in phenolic acids and has important and varied biological bioactivities, on growth performance, mucosal immunity and liver antioxidant status in goldfish (Carassius auratus). The antioxidant activity, alongside the phenolic and flavonoid contents, were also determined in irradiated palm fruit extracts (IPFE). The results showed that IPFE5 had a higher antioxidant activity as well as heightened phenolic and flavonoid contents compared to IPFE10 and IPFE0. Meanwhile, goldfish specimens were randomly divided into three groups with three replicates in each. Subsequently, skin immunity and antioxidant activity in the livers of the goldfish were studied. The growth rates of fish fed with IPFE5 and IPFE10 were significantly higher (p < 0.05) compared to the CTR group. In addition, fish fed with the IPFE5 diet demonstrated increased mucosal immunity compared to the CTR group (p < 0.05). Lipid peroxidation levels as well as antioxidant enzyme activities were also higher in all the IPFE-fed groups compared to the CTR group (p < 0.05). These data showed that 40-day dietary administration of γ-irradiated date extract, especially IPFE5, improved growth performance, mucosal immunity, and liver antioxidant capacity in goldfish. The suitability of administrating this additive in the diet of farmed fish is discussed.