Optimum dietary calcium requirement of Hypophthalmichthys molitrix juveniles

• Published in: Aquaculture research Vol. 53; no. 16; pp. 5455 - 5462
• Main Authors: Khizar, Ayesha, Fatima, Mahroze, Shah, Syed Zakir Hussain, Khan, Noor, Maryam, Khan, Fatima
• Format: Journal Article
• Language: English
• Published: Oxford Hindawi Limited 01.11.2022
• Subjects: Alkaline phosphatase; Bones; Calcium; Calcium (dietary); Carp; Diet; Feeding experiments; Fish; Freshwater fishes; growth performance; Hypophthalmichthys molitrix; Juveniles; mineralization; Minors; Moisture effects; Optimization; Phosphatase; Serum; whole‐body proximate composition; Zinc
• ISSN: 1355-557X; 1365-2109
• DOI: 10.1111/are.16026

A 13‐week feeding trial was conducted to determine the optimum dietary calcium (Ca) requirement of juvenile silver carp, Hypophthalmichthys molitrix (3.20 ± 0.02 g). For this, five isonitrogenous semipurified diets containing 2.3, 5.3, 8.3, 11.1 and 14.2 g/kg Ca levels were formulated. The growth performance of juveniles was significantly affected by Ca supplementation with the maximum increase recorded at 8.3 g/kg Ca and stabilized thereafter (p < 0.05). Whole‐body protein and ash contents were increased (p < 0.05) with increased dietary Ca up to 8.3 g/kg and then levelled off (p < 0.05). However, the moisture and fat contents in whole body were decreased (p < 0.05) with the increased Ca supplementation up to 8.3 g/kg and plateaued thereafter. Calcium and P concentration showed an increasing trend (p < 0.05) with the increasing Ca level up to 11.1 g/kg in whole body and 8.3 g/kg in bones and scales. However, Mg and Zn concentrations were decreased (p < 0.05) with increasing dietary Ca levels. The highest alkaline phosphatase (ALP) activity (p < 0.05) was recorded in the fish‐fed diet containing 11.1 g/kg Ca diet; however, serum Ca, P and Ca/P ratio remained unaffected (p > 0.05). Broken line regression showed that 8.45 g/kg Ca is the optimal requirement for the growth of silver carp. Conclusively, an increase in Ca supplementation up to 8.3 g/kg significantly improved the overall performance of silver carp without urging the negative effects.