Document Type : Original Article
Authors
1
Ph.D. Student of Fisheries, Young Researchers and Elites club, Islamic Azad University, ShahreKord Branch, ShahreKord, Iran.
2
Assistant Professor, Department of Fisheries, Faculty of Fisheries and Environment, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
3
M.Sc. of Fisheries, Department of Fisheries, Faculty of Natural Resources, Islamic Azad University of Tehran Research, Tehran, Iran.
4
M.Sc. of Fisheries, Young Researchers and Elites club, Islamic Azad University, Yasouj Branch, Yasouj, Iran.
Abstract
The aim of the present study was to determine the effects of different levels of probiotic feed supplement (Primalac) on reproductive performance, survival of larvae as well as growth performance and feed utilization, body composition and survival rate of Golden Severum, (Heros severus) fry. The study was performed in a completely randomize design with 1 control group and 3 experimental groups include different level (1, 2.5 and 5 g per kg) of Primalac as probiotic. The study was performed in two separate phases: in first phased on spawners and their larvae and in second phase on performance and feed utilization, body composition of fry. Treatments repeated in triplicates with stocking density of 40 fish per experimental unit. In first phase, spawners were fed on primalac before the first spawning till 5 spawning cycle and reproductive performance parameters were measured. In second phase, fry were fed on experimental diets for 60 days and sampled for determination of above mentioned parameters. The results showed that Primalac significantly increased reproductive performance parameters include fertilization rate, absolute fecundity, hatching rate as well as survival of larvae (P < 0.05). Also, feeding fish with 2.5 or 5 g kg-1 primalac remarkably improved growth parameters (Final weight, weight gain, length increase, SGR) (P < 0.05). Furthermore, feed conversion ratio as well as PER were improved in primalac fed fish (P < 0.05). Also, primalac increased total protein, albumin, globulin and total glucose if fry body (P < 0.05). The results of the present study, revealed that primalac is a suitable probiotic to be used for spawners as well as in hatecheries to improve growth performance and FCR of Golden Severum. Biochemical parameters also showed that primalac improved physiological status of fry.
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