EFFECT OF DIFFERENT STOCKING DENSITY AND FEEDING TYPE ON GROWTH PERFORMANCE, FEED UTILIZATION AND BODY CHEMICAL COMPOSITION OF BLUE TILAPIA (OREOCHROMIS AUREUS) FINGERLINGS

Amal S. Hassan and Ibrahim M. Samra

Department of Fish Production and Aquaculture Systems, Central Laboratory for Aquaculture Research, Abbassa, Abo-Hammad, Sharkia, Egypt.

Received 23/ 11/ 2010

Accepted 27/ 12/ 2010

Abstract

This study was designed to study the effect of stocking density and feeding type on growth performance, feed utilization and body chemical composition of Blue Tilapia (Oreochromis aureus) fingerlings and determine in Central Laboratory for Aquaculture Research, Abbassa, Abou Hammad, Sharkia Governorate. Using in this study 2× 2 factorial designs, two different stocking densities low and high of Blue Tilapia, Oreochromis aureus (2.5 and 5.0 g total biomass/ L )were combined with two different diets (formulated or commercial ) containing 25 % crude protein to obtain 4 experimental treatments were subjected to be studied as the following :

1- The first treatment 2.5 g/ L low stocking density +feed of formulated diet.

2- The second treatment 2.5 g/L low stocking density + feed of commercial diet.

3- The third treatment 5.0 g/ L high stocking density +feed of formulated diet.

4- The fourth treatment 5.0 g/ L high stocking density + feed of commercial diet.

In this study was used twelve glass aquarium, all glass aquarium 80×40 ×40 cm and used three replicate in all treatment and Blue Tilapia fingerlings were reared in the same condition. Fish were daily fed at a rate 3% of their biomass for ten weeks.

Results obtained indicate that:

-There were significant differences in AWG, ADG and SGR among treatments. The first treatment (2.5 g/L stocking density + feed of formulated diet) recorded the highest values for the above parameters, while the lowest level of these values was observed with fourth treatment (5.0 g/ L stocking density + feed of commercial diet).

-Feed conversion ratio (FCR), protein efficiency ratio (PER), protein productive value (PPV %) and energy utilization (EU %) were significantly affected by the experimental treatments.

-The formulated diet at the lowest stocking density in the first and second treatments recorded the best values of feed and protein utilization compared with other treatments.

– Body dry matter (%) was not significantly affected by the experimental treatments, while CP%, EE% and ash % significantly differed among treatments.

-The formulated diet at the lower density recorded the highest CP and EE contents.

-The best economic efficiency (expressed as feed cost / kg weight gain) was observed in the first treatment (2.5 g/L stocking density + feed of formulated diet), While the lowest efficiency was recorded for fourth treatment (5.0 g/ L stocking density +feed of commercial diet).

This is study it can concluded rereading of Blue Tilapia (Oreochromis aureus) fingerlings in low stocking density and using formulated diet as content of 25% protein for gave the best of growth relatives, productive performance, good feed conversation and good body chemical composition compared with high stocking density and fed commercial diet for gave many money by men rearing and culture of these types of fish.