17 M. Z. Arsalan S. M. Hussain A. Javid M. Hussain R. Manzoor M. M. Jalees M. M. Rehan A. Sharif Journal of Animal and Plant Sciences JAPS 20232023/03/24 33 2 416-424 1018-7081 https://doi.org/10.36899/JAPS.2023.2.0631 <p>A 3&times;3 factorial arrangement was used to determine the synergistic effects of citric acid (CA) and phytase (PHY) supplemented canola meal (CM) based diet on growth performance and nutrient digestibility of&nbsp;<em>Cyprinus carpio</em>&nbsp;fingerlings. Canola meal was used as a main ingredient to prepare diets by replacing fishmeal at graded levels such as: 0%, 25%, 50% and 75%. These diets were further supplemented by different levels of CA (0% and 2.5%) and PHY (0 and 750 FTU kg^-1) to formulate a total of 16 test diets. Completely Randomized Design (CRD) was followed to add diets to the fish groups. Chromic oxide (Cr₂O₃) was added as an indigestible marker. Fish were fed at the rate of 5% of their live wet weight. The findings of study revealed that the maximum weight gain% (267.81%), SGR (1.44) and the lowest value of FCR (1.32) were noted when fingerlings were fed on test diet T_12&nbsp;containing 50% canola meal with 750 FTUkg^-1&nbsp;PHY and 2.5% CA supplementation as compared to fish fed on control diet (T₁) having 0% canola meal and without any concentration of CA and PHY. Similarly, optimum nutrient digestibility values such as crude protein (75.06%), crude fat (83.31%) and gross energy (66.45%) were noted when fish fed on the same diet (T₁₂). It may be concluded that fish meal could be optimally replaced with canola meal up to 50%, when supplemented with PHY (750 FTU kg^-1) and CA (2.5%).</p> C. carpio, phytase, citric acid, canola meal, growth, nutrient digestibility Pakistan Agricultural Scientists Forum https://thejaps.org.pk/AbstractView.aspx?mid=ZLG-21-0044