Naslov
Effects of reduced feeding to the growth performances of farmed tuna

Autori
Mišlov Jelavić, Krstina ; Šegvić-Bubić, Tanja ; Grubišić Leon

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
Youmares 2.0, 2nd international network meeting of young marine researchers

Mjesto i datum
Bremerhaven, Njemačka, 07.09.2011. - 09.09.2011

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Bluefin tuna; farming; feeding; growth

Sažetak
It is a common practice amongst tuna farmers to feed tuna (thunnus thynnus L.) to apparent satiation in order to increase biomass and fat content. However, minimising environmental impacts while producing top quality farmed bluefin tuna (BFT) requires employing the best feeding regime strategy to achieve optimal economic and environmental effectiveness. The effects of reduced feeding by 24% of its maximum on the specific growth rate (SGR), food conversion rate (FCR), condition factor (CF), viscerasomatic index (VSI) and hepathosomatic inex (HSI) were analysed. The fish were sampled just after capture in May 2008. and at the end of experiment in February 2010. Stocked fish with an average mass of 8.7 kg were randomly placed in two separate cages. The first group was fed ad libitum, while the second was given a 24% lower daily food ration than the first group. Consumed feed consisted of 60% herring, 25% sardines and 15% mixed pelagic fish (anchovy, mackerel, sardines). Initial body weight increased by 377% in the first group of fish fed ad libitum when compared to 344% in fish subjected to the reduced feeding regime. The SGR was 0.26 % and 0.24 %, while FCR was 14.2 and 12.0 for the fish in the first and second group, respectively. At the end of breeding period, a higher CF was observed in the fish less fed (2.2 ± 0.2 ; mean ± SD) compared to the fish fed ad libitum (1.9 ± 0.2). No significant differences were observed in VSI and HSI among feeding groups. The economic benefit was 520 t less bait spent in the reduced feeding BFT group. Further commercial elaboration of such a practice is needed to optimize both the economic and environmental performance of BFT farming in floating cages along the central Eastern Adriatic.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA