~ 420 ~ International Journal of Fisheries and Aquatic Studies 2017; 5(3): 420-424 E-ISSN: 2347-5129 P-ISSN: 2394-0506 (ICV-Poland) Impact Value: 5.62 (GIF) Impact Factor: 0.549 IJFAS 2017; 5(3): 420-424 © 2017 IJFAS www.fisheriesjournal.com Received: 24-03-2017 Accepted: 25-04-2017 Fajri Khairiz Zaman Department of Aquaculture, Bogor Agricultural University, Bogor, Indonesia Nur Bambang Priyo Utomo 1) Department of Aquaculture, Bogor Agricultural University, Bogor, Indonesia 2) Research Southeast Asian Regional Centre for Tropical Biology, Bogor, Indonesia Mia Setiawati Department of Aquaculture, Bogor Agricultural University, Bogor, Indonesia Alimuddin Department of Aquaculture, Bogor Agricultural University, Bogor, Indonesia Correspondence Nur Bambang Priyo Utomo 1) Department of Aquaculture, Bogor Agricultural University, Bogor, Indonesia 2) Research Southeast Asian Regional Centre for Tropical Biology, Bogor, Indonesia Evaluation of pollard substitution with water hyacinth Eichhornia crassipes on enzyme activity and growth performance of tilapia Oreochromis niloticus Fajri Khairiz Zaman, Nur Bambang Priyo Utomo, Mia Setiawati and Alimuddin Abstract The present study was to subtitute pollard as one of raw materials in fish feed production obtained from the import with other raw material. One potential alternative raw material is water hyacinth Eichhornia crassipes. This research was conducted with 5 treatments and 3 replications namely feed with substitution of pollard with E. crassipes at 0%, 25%, 50%, 75% and 100%. On the test of growth performance, tilapias (Oreochromis niloticus) with the initial weight of 6.55 ± 0.02 g fish -1 were maintained for 60 days. On digestibility test, treatment feeds were added with 0.6% Cr2O3 and fed to tilapia with a weight of 23.70 ± 0.48 g fish -1 . The results show that tilapia fed with 50% replacement rate of pollard yielded similar relative growth, feed efficiency, protein retention and protein digestibility with 0% treatment. The activities of protease, amylase and cellulase decreased due to the increase in water hyacinth in the feed. In conclusion, water hyacinth flour can be used up to 50% as a pollard substitution with 12.5% of material quantity in the diet of tilapia Keywords: Eichhornia crassipes, enzyme activity, growth, tilapia 1. Introduction Culture feed is the major part of production cost in aquaculture activities. In general, feed cost contributes approximately 60-70% of the total production cost in semi-intensive and intensive aquaculture activities (Singh et al. 2006) [15] . The availability and price of imported raw materials are highly dependent on producer countries. The rarely of raw materials leads to higher prices, it is also caused by Dollar exchange rate. Therefore, an alternative raw material to reduce dependence on imported raw materials is needed. One of the materials that could potentially be used as feed ingredients is water hyacinth. Eichhornia crassipes has the ability to adapt from extreme changes in water conditions, nutrient levels, pH, temperature and water level (Sotolu 2012) [17] . Based on the chemical analysis, this plant contains 80.1% organic material, 12.4% protein, amino acids, lysine and methionine, 19.9% crude fiber and 4.72% fat (Chang et al. 2013) [2] . A rapid growth of water hyacinth is often considered as a weed in the water because it can cover water surface. Therefore, water hyacinth is utilized not only for reducing the use of imported raw materials but also for reducing waste waters. The use of water hyacinth in the fish feed will affect the fish growth. Sotolu and Sule (2011) [18] reported that the utilization of water hyacinth flour in replacing soybean meal amounted to 22.91% in catfish showed significantly different fish growth. Utilization of vegetable raw materials may affect the activity of the protease of fish (Liao et al. 2015) [8] . Manufacture of plant-based fish feed should be focused on its optimal level in the feed for effective utilization (Francis et al. 2001) [3] . This research used E. crassipes obtained from Sukabumi (West Java) contained 11.91% protein. The protein content was not much different from pollard (14.54%) which is an imported product. Therefore, this study was performed to evaluate the utilization of E. crassipes in replacing pollard on enzyme activity, growth performance, and feed digestibility test.