Growth and feed consumption of young rainbow trout (Oncorhynchus mykiss) exposed to different photoperiods


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Ergun S. , Yigit M. , Tucker A.

ISRAELI JOURNAL OF AQUACULTURE-BAMIDGEH, cilt.55, ss.132-138, 2003 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 55 Konu: 2
  • Basım Tarihi: 2003
  • Dergi Adı: ISRAELI JOURNAL OF AQUACULTURE-BAMIDGEH
  • Sayfa Sayıları: ss.132-138

Özet

A feeding experiment was carried out in a brackish water (18 ppt) flow-through system to determine the effects of different photoperiods (light hours/dark hours; UD) on feed intake and growth performance of young rainbow trout (Oncorhynchus mykiss). Duplicate groups of fish (35.32 g avg body wt) were exposed to a natural photoperiod, a long photoperiod (16L/8D) or a continuous photoperiod (24L/0D) for 60 days and fed to satiation twice a day. The growth rate, daily feed intake and feeding rate in the natural photoperiod were significantly lower (p<0.05) than in the long and continuous photoperiod groups. Growth was highest in the continuous photoperiod, but did not significantly differ from the long photoperiod. The feed conversion ratio, feed efficiency and gross efficiency in the long and continuous photoperiods were slightly better (about 5-7%) but did not significantly differ (p>0.05) from the natural photoperiod. Survival was not significantly (p>0.05) affected by the treatment. For better growth and a lower food conversion rate, the long photoperiod is recommended for young rainbow trout.

A feeding experiment was carried out in a brackish water (18 ppt) flow-through system to determine

the effects of different photoperiods (light hours/dark hours; L/D) on feed intake and growth

performance of young rainbow trout (Oncorhynchus mykiss). Duplicate groups of fish (35.32 g

avg body wt) were exposed to a natural photoperiod, a long photoperiod (16L/8D) or a continuous

photoperiod (24L/0D) for 60 days and fed to satiation twice a day. The growth rate, daily feed

intake and feeding rate in the natural photoperiod were significantly lower (p<0.05) than in the

long and continuous photoperiod groups. Growth was highest in the continuous photoperiod, but

did not significantly differ from the long photoperiod. The feed conversion ratio, feed efficiency

and gross efficiency in the long and continuous photoperiods were slightly better (about 5-7%)

but did not significantly differ (p>0.05) from the natural photoperiod. Survival was not significantly

(p>0.05) affected by the treatment. For better growth and a lower food conversion rate, the long

photoperiod is recommended for young rainbow trout.