Effects of stocking density and feeding levels on growth and feed efficiency of Nile tilapia (Oreochromis niloticus L.) fry

Abstract

The effects of stocking density and feeding levels on larval survival, growth rates, feed utilization efficiency and body composition of Nile tilapia (Oreochromis niloticus L.) fry were investigated in two consecutive experiments. In experiment 1, swimup fry (0.016 g average body weight) were stocked in 20‐L fibreglass tanks, in a closed, recirculating indoor system, at five stocking densities (3, 5, 10, 15 and 20 fry L−1) and fed a larval test diet (40% crude protein) to apparent satiation, three times a day, for 40 days. Fish survival, percentage weight gain and specific growth rate (% SGR) were negatively correlated with stocking density. The best performance was achieved at 3 fry L−1. However, no significant differences in growth parameters were found between 3 and 5 fry L−1. Body composition was not significantly affected by stocking density. In experiment 2, fry (0.016 g average body weight) were stocked at 5 fry L−1, and fed a larval test diet (40% crude protein) at six feeding levels (10%, 20%, 25%, 30% and 35% BW day−1) and to satiation, three times a day for 40 days. Fish growth rates and survival were extremely poor at 10% feeding level, and improved significantly with increasing feeding levels up to 30%, and levelled off with further increase in feeding levels. On the contrary, feed conversion ratio (FCR) and protein production value (PPV) were negatively correlated with feeding level. The lowest feeding level (10%) produced significantly lower body lipid and higher protein and ash than other feeding levels. The present results suggest that the optimum stocking density and feeding level of Nile tilapia fry are 5 fry L−1 and 30% per day respectively.

Performance and economic indicators of a large scale fish farming in Mato Grosso, Brazil

“…On the other hand, fish farmed in highly populated ponds usually display lower growth rates (El-Sayed, 2002). The results of this study follow this trend, since the higher stocking biomass observed in pond 6 translated into lower slaughtering weight, despite higher productivity, compared with the less populated ponds 2, 3, 4, 5 and 9.…”

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“…The best feeding strategy for tambaqui during the first growth phase in cages was found to be 10% body weight/day (Silva and Gomes, 2007). The optimum stocking density and feeding level of Nile tilapia fry were reported to be 5 fry/L and 30% (crude protein) daily (El-Sayed, 2002). The optimum commercial stocking density, for survival, fast growth and high production rates of silver perch were examined by Rowland et al (2006).…”

“…The type of feed and feeding frequency has a direct effect on water quality, growth, fish welfare and responses of the immune system (Riche et al, 2004;Silva et al, 2007;Garcia and Villarroel, 2009;Luthada and Jerling, 2013). Stocking density and ration size also influence growth, survival, and the innate immune system (El-Sayed, 2002;Rowland et al, 2006;Salas-Leiton et al, 2010). Farming factors may cause stress and disturb fish homeostasis.…”

Farinha de resíduos da filetagem de tilápias na alimentação de tilápia-do-nilo (Oreochromis niloticus) na fase de reversão sexual

“…As tilápias representam o segundo peixe de água doce mais criado no mundo, tanto em regiões tropicais quanto subtropicais e temperadas (El-Sayed, 2002;Borghetti et al, 2003) e, em razão de seu potencial, muitos aspectos relacionados ao manejo e à nutrição têm sido estudados (Furuya et al, 2001;Hayashi et al, 2002;Boscolo et al, 2002ab;El-Sayed, 2002;Meurer et al, 2003a). A fase inicial da criação é responsável pela produção de alevinos em quantidade e qualidade para o sucesso nas fases posteriores.…”