<p class="BasicParagraph" align="center"><strong>ABSTRACT</strong></p><p class="BasicParagraph" align="center"><strong><br /></strong></p><p class="BasicParagraph" align="center"> </p><p class="Pa2">This experiment was aimed to investigate the effects of protein hydrolysates on growth performance and immune response of the Asian sea bass <em>Lates calcarifer </em>Bloch. The experiment was performed in two different rearing period, namely nursery and grow out by using completely randomized design. Experimental fish were fed with three types of diets and each treatment was repeated three times: a local commercial diet (control), coated or not, with 2%, and 3% of protein hydrolysates. Challenge test was performed with <em>Vibrio parahaemolyticus </em>at a density of 105 sel/mL by using immersion method. The results showed that the the neutrofil, leukocyte and monocyte of the fish fed on protein hydrolisates were significantly higher than those non-supplemented group (P<0.05). Meanwhile, the lymphocyte on the fish treated with hydrolisates showed no difference amongst treatments (P<0.05). The growth performance of Asian sea bass fed on protein hydrolisates significantly improved the total fish weight (g), relative weight gain, specific growth rate, final weight (g) and final length (cm) in comparison to the control (P<0.05) both at nursery and grow out phase. Higher survival both at the nursery and grow out phase were obtained by the group fed with 3% protein hydrolisates: 97.28±0.18% and 86.0±4.32%. Followed with 2% supplementation level 96.75±0.28% and 78.4±7.7%. The lowest survival was shown by the control group with 93.65±0.13% and 20.1±21.1% from nursery and grow-out phase respectively. Results of challenged test showed that the protein hydrolisates supplementation was able to improve the post-challenged survival and resistency of Asian sea bass against <em>V. parahaemolyticus </em>infection. Fish treated with 3% protein hydrolisates generated higher survival 78,33±2,89%, followed by treatment 2% 73,33±5,77%, and control 31,67±7,64% after five days post immersion (P<0.05).</p><p class="Default"> </p><p class="Pa2">Keywords: Asian sea bass, protein hydrolisates, growth, immune system</p><p class="BasicParagraph" align="center"><strong> </strong></p><br class="BasicParagraph" /><p class="BasicParagraph"> </p><p class="BasicParagraph"> </p><p class="BasicParagraph" align="center"><strong>ABSTRAK</strong></p><p class="BasicParagraph"><strong> </strong></p><p class="Pa2">Penelitian ini bertujuan untuk menguji efektivitas suplementasi protein hidrolisis pada pakan terhadap respons kekebalan tubuh dan performa pertumbuhan ikan kakap putih <em>Lates calcarifer</em>. Penelitian dilakukan di dua fase pemeliharaan, yakni fase pendederan dan pembesaran dengan menggunakan rancangan acak lengkap. Penelitian ini menggunakan tiga perlakuan dan masing–masing perlakuan memiliki tiga ulangan, dengan deskripsi perlakuan adalah kontrol, aplikasi 3% dan 2% protein hidrolisis. Uji tantang dilakukan dengan menggunakan <em>Vibrio parahaemolyticus </em>pada konsentrasi 105 sel/mL dengan metode perendaman. Hasil analisa respons kekebalan tubuh menunjukkan bahwa neutrofil, leukosit, dan monosit pada kelompok ikan yang mendapatkan aplikasi protein hidrolisis meningkat secara nyata dibandingkan kontrol (P<0,05). Sementara limfosit pada kelompok perlakuan protein hidrolisis tidak memiliki perbedaan yang nyata dibandingkan kontrol (P<0,05). Performa pertumbuhan ikan kakap putih yang mendapatkan suplementasi protein hidrolisis juga memiliki total bobot (g), % bobot relatif, % laju pertumbuhan spesifik, bobot akhir (g) dan panjang akhir (cm) yang secara nyata lebih baik jika dibandingkan dengan kontrol (P<0,05) baik pada masa pemeliharaan di pendederan maupun di pembesaran. Sintasan paling tinggi pada fase pendederan dan pembesaran terdapat pada kelompok suplementasi 3% dengan 97,28±0,18% dan 86,0±4,3%. Diikuti oleh kelompok 2% dengan 96,75±0,28% dan 78,4±7,7%; dan paling rendah diperoleh pada kelompok kontrol dengan 93,65±0,13 % dan 20,1±21,1% masing-masing dari fase pembenihan dan pembesaran. Hasil uji tantang menunjukkan bahwa suplementasi protein hidrolisis mampu meningkatkan sintasan dan meningkatkan resistensi ikan uji terhadap infeksi <em>V. parahaemolyticus</em>. Pemberian protein hidrolisis dengan konsentrasi 3% merupakan dosis terbaik dengan sintasan 78,33±2,89%, diikuti oleh aplikasi 2% dengan 73,33±5,77% dan kontrol dengan 31,67±7,64% setelah lima hari masa uji tantang (P<0,05).</p><p class="Default"> </p><p class="Pa2">Kata kunci: ikan kakap putih, protein hidrolisis, pertumbuhan, sistem kekebalan tubuh</p><br /><p> </p>
A comparative laboratory trial on the effect of Sargassum wightii incorporated formulated feed on growth performance and immunity development of Asian sea bass Lates calcarifer (Bloch 1790): can it be an alternative to commercial feed?
