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Phosphorus requirement of Catla ( Catla catla Hamilton) fingerlings based on growth, whole‐body phosphorus concentration and non‐faecal phosphorus excretion
Author(s) -
Sukumaran Krishna,
Pal Asim Kumar,
Sahu Narottam Prasad,
Debnath Dipesh,
Patro Biswamitra
Publication year - 2009
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/j.1365-2109.2008.02073.x
Subject(s) - catla , phosphorus , zoology , biology , carp , fish <actinopterygii> , fishery , chemistry , organic chemistry
A 120‐day feeding trial was conducted to determine the dietary requirement of phosphorus for Indian major carp, catla ( Catla catla ) fingerlings. Four hundred and eighty fingerlings (mean body weight: 4.23±0.87 g) were randomly distributed among eight treatment groups with three replicates each. Eight isonitrogenous and isocaloric semi‐purified diets (crude protein: 35% and crude lipid: 8.5%) were formulated with graded levels of phosphorus using KH 2 PO 4 (T 1 : control, 0.1%; T 2 : 0.3%; T 3 : 0.5%; T 4 : 0.7%; T 5 : 0.9%; T 6 : 1.1%; T 7 : 1.3%; T 8 : 1.5%) and fed to the respective groups. Twenty fish were stocked in 150 L plastic tanks and fed to apparent satiation twice a day. Specific growth rate (SGR) significantly ( P <0.05) increased with increasing dietary phosphorus concentration from 0.73% to 1.27%, after which there was a slight decline in growth at 1.1% available phosphorus (aP) and remained constant thereafter. The quadratic broken‐line model based on growth was Y =317.5−581(0.64− x ) (0.64− x ); R 2 =0.73. Moisture and crude protein contents of whole body were similar among all the treatments. However, the ether extract in T 1 group was significantly ( P <0.05) higher than all the other treatments. The whole‐body phosphorus content increased significantly ( P <0.05) with an increase in phosphorus in the diets. The one‐slope broken‐line model based on whole‐body phosphorus concentration was Y =4.07−1.63 (0.71− x ); R 2 =0.48. The one‐slope broken‐line model for non‐faecal phosphorus excretion as inorganic phosphorus (Pi) for 24 h revealed a trend of Y =12.67+73.96 ( x −0.6); R 2 =0.81. Minimum aP requirements based on weight gain (%), whole‐body phosphorus content and phosphorus excretion were 0.64%, 0.71% and 0.6%, respectively. Hence, the dietary aP requirement of catla fingerlings ranges from 0.6% to 0.71%.