EFFECT OF GREEN SEAWEED (ULVA SP.) AND PROBIOTIC (LACTOBACILLUS SP.) AS DIETARY SUPPLEMENTS ON GROWTH PERFORMANCE AND FEED UTILIZATION OF RED TILAPIA (♀ O. MOSSAMBICUS ×
♂ O. NILOTICUS)

Talaat N. Amer* and Nader E. El-Tawil

Department of Fish Nutrition, Central Laboratory for Aquaculture Research, CLAR, Agriculture Research Center, Egypt.

*Corresponding author’s e-mail: [email protected]

Received 4/ 9/ 2011 Accepted 5/ 10/ 2011

Abstract

This experiment was carried out to study the effect of green seaweed (Ulva sp.) and dried probiotic bacteria (Lactobacillus sp.) as dietary supplements on growth performance, body composition and feed utilization of red tilapia (Oreochromis sp.) (1.07 g initial body weight). Four practical diets containing 28% crude protein and 242 kcal metabolizable energy /100 g diet were used. Diets were: T1 without seaweed or probiotic supplements (control); T2 contained 10% seaweed (SW); T3 contained 0.5% probiotic (P) and T4 contained both of 10% seaweed and 0.5% probiotic (SW + P). Red tilapia fed the practical diets for 70 days in triplicate recirculating aquaria. The results showed that final body weight (FBW), weight gain (WG) and specific growth rate (SGR%/day) of fish
maintained at (SW) or (P) were better significantly (P ≤ 0.05) than fish maintained at control diet or (SW + P) diet. On the other hand, feed utilization parameters were affected significantly by different treatments. The best significant values (P ≤ 0.05) of feed conversion ratio (FCR), protein efficiency ratio (PER), protein productive value (PPV %), and energy retention (ER %) were found with fish maintained at (SW), (P) and (SW + P) diets, while control diet had the lowest significant (P ≤ 0.05) values. Insignificant differences (P > 0.05) were observed in fish body moisture, crude fat and crude protein contents among treatments. Therefore, it could be concluded that the addition of green seaweed (Ulva sp.) or probiotic (Lactobacillus sp.,) as feed supplements to red tilapia (Oreochromis sp.) diets have a positive effect on growth performance and feed utilization of fish.

Keywords: Red tilapia Oreochromis sp., probiotic (Lactobacillus sp.); seaweed (Ulva sp.), growth performance, feed utilization.