Influence of graded levels of protein on external morphometrics, length-length (LLR) and length-weight relationship (LWR) of Genetically Improved Farmed Tilapia(GIFT) from Southern Punjab, Pakistan

Abstract

This study was planned to evaluate the influence of different levels of crude protein (CP) 15% (T1), 20% (T2) and 25% (T3) on external morphometric parameters, LLR, LWR and condition factor of Genetically Improved Farmed Tilapia (GIFT) fingerlings, a developed strain of Nile tilapia (Oreochromis niloticus). An increase in the external morphometric parameters was obtained with increasing protein level and highest values for mean wet weight (30.48±17.54) and Total length (TL) 12.84±1.97wereobserved in T3 (25%CP) fish. Correlation coefficient values (r = 0.961) and (r= 0.992) yielded highly significant (P<0.001) LWR in T1 and T3 respectively while significant (P<0.01) in T2 (r=0.856). Regression coefficient ‘b’ exhibited negative (T1= 2.829, T2= 2.069) and Positive (b=3.149) allometry in T3 group. Condition factor also exhibited increasing trend with dietary protein level yielding 1.52, 1.56 and 1.68 in T1, T2 and T3 respectively indicating good environmental and fish condition. All lengths of external morphometric parameters showed positive relationship both with total length and wet weight for insignificant and significant correlations. Protein feed of 25% (T3) was found to exhibit highest growth, in terms of weight and estimated morphometrics, in GIFT as compared to T1 and T2 in the current study.