Effects of using Lactobacillus rhamnosus probiotic and Nigella sativa (black seed) on the growth parameters of Rainbow trout (Oncorhynchus mykiss)

In this work the effect of Lactobacillus rhamnosus and black seed (Nigella sativa) powder was studied on growth and feeding parameters of rainbow trout. The feeding treatments used were (1) rainbow trout commercial diet (control), (2) commercial diet supplemented with Lactobacillus rhamnosus (108 CFU/Kg feed), (3, 4, 5) commercial diet supplemented with the same probiotic bacteria and 25, 50 and 100 g black seed powder/Kg feed respectively. 900 rain bow trout fingerlings (average wt. 36g) were cultured in 15 concrete tanks containing 400 L underground well water for a period of 60 days. The fish were fed three times every day to apparent satiation. Maximum weight gain, standard length, specific growth rate, feed efficiency ratio and daily feed intake and minimum feed efficiency rate (FCR) were observed in group fed on feed containing probiotic bacteria and 25 g black seed/Kg feed compared to the control and the fish received 100 g black seed in their feed (P < 0.05). It was concluded that supplementation of 108 CFU Lactobacillus rhamnosus and 25 g black seed powder/Kg feed can positively influence the growth and feeding parameters of rain bow trout.