Department of Fisheries, Faculty of Animal Sciences and Fisheries, Sari Agricultural Sciences and Natural Resources University, Sari, Iran , hoseinoraji@yahoo.com
Abstract: (104 Views)
Introduction: The aim of this study was to investigate the effect of different levels of lysine on growth performance, carcass composition and digestibility of nutrients in rainbow trout fed with a low protein diet. Materials and Methods: For this purpose, 400 fish with an average initial weight of 6 grams were purchased and distributed in 18 tanks for 8 weeks. Six experimental treatments include diet containing 42% protein and 24% fish meal (control 1), 37% protein and containing 24% fish meal (control 2), 37% protein and containing 12% fish meal (control 3), and diet The ones containing control 3 as a base were supplemented with 0.25, 0.5 and 1% lysine. The treatments were considered in 3 replications with 20 pieces of fish for each replication. Results and Discussion: The result showed that decreasing the percentage of dietary protein led to a significant decrease in final weight, increase in body weight and specific growth rate (P<0.05). Adding different levels of lysine to the diet improved these values so that they were not significantly different compared to control 1 (P>0.05). The food conversion was significantly improved in fed fish by 0.25% and 0.5% (P<0.05). Also, the protein of fish carcasses fed with 0.5% lysine was similar to control 1, and this amount decreased significantly in other treatments (P<0.05). In addition, protein digestibility decreased significantly with the reduction of both protein and fish meal in the diet (control 3), while in controls 1 and 2 and treatments containing 0.25 and 0.5% lysine, it was higher than others experimental treatments. Conclusion: it seems that by adding 0.5% of lysine, the protein in the diet of baby rainbow trout can be reduced from 42% to 37% and fish meal from 24% to 12% without having a detrimental effect on growth. Carcass quality and protein digestibility.
Ouraji H, Mehrani R, Firozbakhsh F, Jani khalili K. The effect of lysine supplementation on growth performance, carcass composition and digestibility of nutrients in juvenile rainbow trout (Oncorhynchus mykiss) fed with a low protein diet. JAD 2025; 19 (3) :86-99 URL: http://aqudev.liau.ac.ir/article-1-857-en.html