Growth and production performance of tilapia (Oreochromis niloticus) in intensive and semi-intensive tank based aquaculture system using floating feed

Abstract

The stocking density is considered one of the most critical factors that affects the growth performance and production as well. The study was aimed to compare the growth parameters of tilapia at different stocking densities. The growth performance usually considered as the data of the beginning and the end of production cycle avoiding intermediary data for the measurement is highly criticized by the scholars due to the abjection of the accuracy. However, the utilization of floating feed by fish can be acquainted addressing the growth performance at different stages of fish growth. To evaluate the growth performance, the study was conducted in twelve concrete tanks under an outdoor laboratory shed from 10 th May to 29 th July, 2017. Tilapia (Oreochromis niloticus) fry was released at the rate of 8 fry per tank as per the recommended stocking density of 320 fishes/decimal and 4 fry per tank equivalent to the stocking density of 160 fishes/decimal in intensive semi-intensive aquaculture system, respectively. To evaluate the growth performance floating feed was used for feeding the fish during the experimental period for T1 (Intensive) and T2 (Semi-intensive), respectively. Each with three replications at the rate of 20%, 15%, and 10% of the body weight feed was supplied in 1 st , 2 nd and 3 rd month, respectively. The daily ration of feed was delivered to fish in the morning and at the evening dividing into two parts. Aeration facilities using air stone aerator were installed for 24 hours. The weight of fish was recorded using digital balance in 3 days interval to assume the trend of consecutive growth of fish while a customized scoop net was used to sample the fish. Water quality parameters i.e., temperature and dissolved oxygen (DO) were recorded two times (morning & evening) daily. The weight gains of fish were 132.23±1.29 and 63.12±4.97gm for T1 and T2, respectively. The mean percent weight gain of tilapia was higher in T1 (1715.05±0.00) than T2 (747±0.00 gm). Feed conversion ratio (FCR) in T1 and T2 were 2.53±0.18 and 2.13±0.20, respectively. The specific growth rates (SGR) of tilapia in T1 6.26.98±2.28 and 4.78±3.83 considering the data at the beginning and the end of the production cycle, respectively. However, the growth performance and SGR was higher at the initial stage of production cycle and lower in the later stages. Higher total production was obtained in T1 (1119.52 g) than T2 (830.96 g) with 100% survival in both the treatments.