Effect of synthetic and algal astaxanthin levels on egg astaxanthin content of rainbow trout (Oncorhynchus mykiss)

This research was done in a trout farm in Kohkiloyeh and Boyer- Ahmad province. The main object of this study was comparing of two sources of astaxanthin (synthetic or algae) in feed on astaxanthin content of egg in rainbow trout. It was considered seven groups consisting six treatments (T1-T6) in two different astaxanthin sources and a control (C) (without astaxanthin). So, algal astaxanthin (haematococcus pluvialis) in the three levels of 2.67, 3.55 and 8gr/kg food (T1,T2, T3); and synthetic astaxanthin in three levels of 40, 80 and 120mg/kg food in diet (T4, T5, T6) examined on 140 trout broods (3-4 years) for 4 months, before the spawning season. Astaxanthin content of obtained eggs from all treatments in spawning season was measured by HPLC apparatus. The highest and the lowest amount of egg astaxanthin were observed in T3 and C respectively. In each astaxanthin group, a significant difference was obtained between averages in treatments (P <0.05), as T3 was the highest between them. No significant difference was observed between synthetic astaxanthin treatments (T4, T5 and T6) and T1 (the lowest level of algal astaxanthin). Treatments T2 and T6 also had the same function in term of saving astaxanthin in eggs. It also concluded that natural astaxanthin (Haematococcus pluvialis) for the reason that contains supplementary nutritious, is extraordinary preferable than synthetic astaxanthin to improve astaxanthin content of egg in rainbow trout.