Effect of soybean meal (SBM) on growth and hematological parameters of rohu (Labeo rohita) and grass carp (Ctenopharyngodon idella)

This study investigates the efficacy of soybean meal (SBM) as a potential protein source in aquafeed, focusing on its effects on the growth and hematological parameters of rohu (Labeo rohita) and grass carp (Ctenopharyngodon idella). The research was conducted at the Microbiology and Immunology Laboratory, University of Agriculture, Faisalabad. With global demand for fishmeal exceeding supply, alternative protein sources, such as SBM, are increasingly crucial for sustainable aquaculture. The study, spanning 7 weeks, involved assigning rohu and grass carp into control (fish meal) and experimental soybean meal (SBM) groups. Growth parameters, including weight, length, specific growth rate (SGR), feed conversion ratio (FCR), and survival rate, were monitored, alongside hematological analyses. The fish were fed on an experimental diet at a feeding level of 2% of body weight. The results indicated comparable growth performance between SBM-fed and fishmeal-fed groups, with SBM potentially enhancing survival rates. Body weight gain and SGR increased significantly compared to the control group fed with FM in rohu. However, for grass carp, there was no significant difference in weight gain and SGR values when fed SBM compared to FM. For rohu, the hematological studies showed significantly higher red blood cells, hemoglobin, hematocrit, white blood cells, and leucocytes. For grass carp RBCs, hemoglobin, and hematocrit values showed a declining tendency with experimental feed; besides that, there was a prominent rise in white blood cell (WBC) count and lymphocytes. These results suggested that SBM could be incorporated at varying percentages in carp feed, considering enhanced growth performance and hematological status as a cost-effective alternative protein source strategy to overcome the cost of fish meal protein in the aquaculture industry.