Effects of irradiated Ergosan on the growth performance and mucus biological components of rainbow trout Oncorhynchus mykiss

Abstract

Eff ects of irradiated and non-irradiated Ergosan extract (alginic acid) on rainbow trout growth performance and skin mucosal immunity were compared. Ergosan was irradiated at 30 kGy in a cobalt-60 irradiator. A total of 252 fi sh (128.03±9.4 g) were randomly divided into four equal groups, given the basal diet either unsupplemented with Ergosan (control group) or supplemented with crude Ergosan (5 g/kg), ethanol-extracted Ergosan (0.33 g/kg) or irradiated Ergosan (0.33 g/kg) according to this protocol: basal diet for 15 days, treatment diet for 15 days, basal diet for 10 days and treatment diet for 15 days. Highest growth performance was observed in fi sh fed irradiated Ergosan ( P <0.05). Dietary administration of diff erent Ergosan types did not cause any changes in mucus protein level, but improved alkaline phosphatase level and hemagglutination titer compared with the control (basal diet without Ergosan) on day 55 of feeding trial ( P <0.05). Furthermore, the highest value of lysozyme activity was observed in gamma-irradiated Ergosan on day 55. In conclusion, gamma-irradiated Ergosan at 0.33 g/kg was found to improve growth performance and mucus biological components signifi cantly in comparison with the control group (basal diet without Ergosan).

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

“…For example, γ-irradiation of feed with 20% soybean meal improved protein digestibility and increased growth in fighting fish (Betta splendens) [38]. Rainbow trout (Oncorhynchus mykiss) also showed a higher uptake of γ-irradiated Ergosan in the intestine compared to crude Ergosan, which resulted in improved growth performance [39]. More recently, it was revealed that the use of γ-irradiated propolis extract at 10 and 30 kGy in the diet of common carp (Cyprinus carpio) boosted growth rates [40].…”

“…There have been few works carried out to study the effects of irradiated feed additives in fish mucosal immunity. For example, γ-irradiated alginic acid boosted skin mucosal immunity and resistance to crowding stress in rainbow trout [39,45]. Feeding with date fruit extract also increased mucosal immune parameters (lysozyme, protease and alkaline phosphatase activity) in common carp fry skin [16].…”

Variations of kidney, liver and spleen total sialic acid levels in immunized rainbow trout (Oncorhynchus mykiss) against Ichthyophthirius multifiliis

“…Two hundred and twenty-five ( 225) parasite free fish were randomly allocated into 5 groups in triplicate at a density of 15 fish per aquarium, equipped with biological filtration. The vaccine dose rate was 100 gamma-irradiation trophonts per 150 gram fish body weight (via the bath method) (SHEIKHZADEH et al, 2016). The1 st group was immunized with 100 gamma-irradiation (170 Gray) inactive trophonts, the 2 nd group immunized with alginate nanoparticles, the 3 rd group immunized with10,000 live trophonts (as the positive control group), and the 4 th group was the negative control (uninfected rainbow trout).…”