The effect of simultaneous feeding of BioAqua probiotics and soy-bean lecithin on reproductive performance of female rainbow trout (Oncorhynchus mykiss)

In this study, the effects of different levels of dietary supplementation with probiotic (BioAqua) and soy-bean lecithin on reproductive efficiency (absolute and relative fecundity, number of eggs per gram, egg diameter, percentage of fertilization and percentage of eyed-egg) of female rainbow trout (Oncorhynchus mykiss) were investigated. For this purpose, the broodstock (2.73±0.02 kg) were fed with 5 different experimental diets including control, B2L6 (2 grams/kg of BioAqua probiotics and 6 percent soy lecithin), B2L9, B4L6 and B4L9 with the rate of one percent of their body weight once a day (at 10 A.M) for two months. The highest absolute   relative fecundity, percentage of fertilization, and percentage of eyed-egg were significantly different in B4L9 treatment (7153.01±76.89, 2604.23±23.77, 99±1%, and 97.33±1.15%, respectively) compared to the control treatment (5304.64±143.09, 1950.05±26.46, 93.33±1.15% and 91±1%, respectively; P<0.05). Also, the largest egg diameter was recorded in B2L9 and B4L9 treatments (5.01±0.07 and 5.05±0.04 mm, respectively), which were significantly different from other treatments (P<0.05). Furthermore, the lowest number of eggs per gram was obtained in B4L9 treatment (15±0.3), which had a significant difference with the control treatment (17.2±0.4; P<0.05). The absolute and relative fecundity and number of eggs per gram in B2L6, B4L6 and B2L9 treatments were not significantly different (P>0.05). The result of the current study revealed that simultaneous dietary supplementation of at least two grams per kilogram of BioAqua probiotic along with at least six percent soy-bean lecithin improve the reproductive efficiency in female rainbow trout.