Now showing items 1-6 of 6

    • Article

      Dietary administration of dehydroepiandrosterone hormone influences sex differentiation of hybrid red tilapia (O. niloticus x O. mossambicus) larvae 

      AH Mohamed, RFM Traifalgar, AE Serrano Jr., JP Peralta & FL Pedroso - Journal of Fisheries and Aquatic Science, 2012 - Academic Journals, New York
      Effects of a steroid hormone Dehydroepiandrosterone (DHEA) on sex differentiation of hybrid red Tilapia Oreochromis niloticus x O. mossambicus larvae were investigated. Three day-old tilapia larvae were fed diets supplemented with varying concentrations of DHEA (0, 20, 40, 80 and 160 mg kg-1 feed) for 24 days. A positive control group fed with diet containing 60 mg kg-1 of 17α-methyl testosterone was also included in the experimental run. Results indicate that among the DHEA treatment groups, larvae fed with 160 mg kg-1 DHEA showed the highest percentage of males that is comparable to the number of differentiated male fish observed in treatment group receiving the 17α-methyl testosterone as the positive control group. DHEA supplementation also improves weight gain and enhances feed conversion ratio. These findings suggest that DHEA can be used as a dietary supplement to induce masculinization and can improve the growth performance of tilapia larvae.
    • Article

      Dietary substitution of protein concentrate of Ulva lactuca for soybean meal in the black tiger shrimp Penaeus monodon fry 

      AE Serrano Jr. & RB Santizo - Animal Biology and Animal Husbandry, 2014 - Bioflux Society
      A feeding trial was conducted to test the protein concentrate of the green seaweed Ulva lactuca as a substitute for soybean meal in the diet of the black tiger shrimp Penaeus monodon fry. Experimental diets containing various replacement levels for soybean meal by weight were prepared, namely 0 (control diet), 15, 30 or 45% Ulva protein concentrate (UPC). Survival rate was not affected by the diets. Feed intake (FI) was statistically similar in shrimp fed the control diet and diet containing 15% UPC replacement while the FI of shrimps fed diets containing 30% and 45% were lower and were not significantly different from each other. SGR of shrimps fed the control diet was not significantly different from the values of those fed diets containing 15% and 30% UPC replacements while those fed diets containing 45% UPC replacement exhibited significantly the lowest SGR. Protein gained of shrimps were statistically similar between those fed the control diet and those fed diets with 15% and 30% UPC while those fed diets at 45% UPC was significantly lower than the three groups. Protein efficiency ratio (PER) was unaffected by the dietary treatments. Ulva protein concentrate could be a substitute for soybean meal in the diet of Penaeus monodon fry up to 30% without compromising the survival, growth and feed utilization efficiency of the shrimp despite lower feed intake.
    • Article

      Lysine and arginine requirements of juvenile Asian sea bass (Lates calcarifer) 

      DP Murillo-Gurrea, RM Coloso, IG Borlongan & AE Serrano Jr. - Journal of Applied Ichthyology, 2001 - Blackwell Publishing
      Two separate experiments were conducted to determine the dietary requirements of juvenile Asian sea bass Lates calcarifer Bloch for lysine and arginine. Fish (average initial weight: lysine experiment, 13.12 ± 0.12 g; arginine experiment, 2.56 ± 0.13 g) were given amino acid test diets for 12 weeks containing fish meal, zein, squid meal, and crystalline amino acids. Each set of isonitrogenous and isocaloric test diets contained graded levels of L-lysine or L-arginine. The feeding rate in the lysine experiment was at 4–2.5% of the body weight day−1, while in the arginine experiment it was at 10–4% of the body weight day−1. The fish (20 per tank, lysine experiment; 15 per tank, arginine experiment) were reared in 500-L fibreglass tanks with continuous flowthrough sea water at 27 °C and salinity of 31 ppt in the lysine experiment and at 29 °C and salinity of 29 ppt in the arginine experiment. The experiments were in a completely randomized design with two replicates per treatment. Survival was high in fish given adequate lysine or arginine. Mean percentage weight gains were significantly different in fish fed varying levels of lysine or arginine. Fish fed high levels of L-arginine suffered high mortalities. No significant differences were obtained in the feed efficiency ratios (FER, g gain g−1 feed) of fish fed graded lysine, although the values tended to increase as the dietary lysine level was increased up to the requirement level. In contrast, in the arginine experiment, significant differences in FER of fish among treatments were obtained; the highest FER was observed in fish fed the diet containing an optimum arginine level. On the basis of the growth response, survival, and FER, the lysine and arginine requirements of juvenile Asian sea bass were estimated to be 20.6 g kg−1 dry diet (4.5% protein) and 18.2 g kg−1 dry diet (3.8% protein), respectively. These data will be useful in the further refinement of practical diet formulations for the Asian sea bass.
    • Article

      Potential use of the sea lettuce Ulva lactuca replacing soybean meal in the diet of the black tiger shrimp Penaeus monodon juvenile 

      AE Serrano Jr., RB Santizo & BLM Tumbokon - Aquaculture, Aquarium, Conservation and Legislation, 2015 - Bioflux
      To evaluate the biological value of incorporating the sea lettuce Ulva lactuca meal in the diet of the black tiger shrimp (Penaeus monodon), 3 diets were fed to groups of shrimps containing two levels (15% and 30% replacement of soybean meal) of the sea lettuce for 90 days. Biological parameters were determined either periodically or at the termination of the experiment. Specific growth rate (SGR) of shrimp fed the control diet and those fed with the diet containing 15% replacement were not significantly different from each other while that of shrimp fed 30% soybean replacement was slightly but significantly inferior. All other parameters such as survival rate, feed intake, food conversion efficiency, protein efficiency ratio protein and lipid deposited and body composition were all statistically similar between the experimental groups of shrimp. Thus, the 30% replacement level or 10.5% inclusion level could be used in the diet of the shrimp P. monodon. When performances were compared with the best result in incorporating U. lactuca protein concentrate from a previous study and that in the present study (both were 30% replacement or 10.5 inclusion level), they were statistically similar. Thus, the raw U. lactuca meal is recommended because it did not require additional processing to produce the concentrated seaweed.
    • Article

      Protein concentrate of Ulva intestinalis (Chlorophyta, Ulvaceae) could replace soybean meal in the diet of Oreochromis niloticus fry 

      AE Serrano Jr. & JIL Aquino - Aquaculture, Aquarium, Conservation and Legislation, 2014 - Bioflux
      An experiment was conducted to evaluate the effects of replacing soybean meal with the protein concentrate of Ulva intestinalis (UPC) in the diet of juvenile Nile tilapia, Oreochromis niloticus. Four experimental diets were formulated to replace 0, 15, 30 or 45% of soybean meal by weight and were fed to group of fish for 90 days. Results showed that survival rates were high and independent of dietary treatment. Feed intake decreased as level of inclusion of UPC increased. Food conversion ratios of Nile tilapia fry fed the experimental diets were all statistically similar. Weight gain and specific growth rate of Nile tilapia fry fed with the diet containing 15% replacement was statistically similar with those of fish fed with the control diet. Thus, U. intestinalis protein concentrate could replace 15% by weight of the imported soybean meal without negatively affecting food conversion ratio, weight gain and specific growth rate; this substitution could mean slightly cheaper formulated diets for the Nile tilapia fry and fingerlings.
    • Book chapter

      Use of soybean meal and rice bran in formulated diets for the grouper Epinephelus coioides 

      ET Marasigan, SL Miag-ao & AE Serrano - In T Bagarinao (Ed.), Research Output of the Fisheries Sector Program, 2007 - Bureau of Agricultural Research, Department of Agriculture
      Two diets were formulated to include 8–14% soybean meal and 9–18% rice bran, 34–40% fish meal, 4–5% mussel meal, and 7–8% Acetes shrimp meal, and 11–13% cod liver oil. Soy bean meal and rice bran were included at 4:1 ratio together to replace 12.5% and 25% of the animal protein sources in the two diets. The two diets were prepared in dry D form and moist M form. The four test diets, D12.5, M12.5, D25, and M25 diets had 40–42% protein and 4,000 kcal/g gross energy. The control diet used was a dry diet with 44% crude protein and 4,260 kcal/g, made with 30% Peruvian fish meal, 8% squid meal, 22% Acetes shrimp meal, 8% cod liver oil, 8% soybean oil, but no plant protein sources. The five diets were fed to juvenile grouper (mean weights ranging from 1.63 ± 0.47 to 2.41 ± 0.91 g) in indoor 400 L concrete tanks (10 fish per tank). After 10 weeks, growth, feed intake, feed conversion ratios (1.2–2.2), and survival (60–80%) of juvenile grouper were not significantly different between the test diets and the control. The carcass composition of the harvested grouper was not significantly different among diets. Protein utilization was best among the fish fed the test diet D12.5. This study showed that soybean meal and rice bran at 4:1 ratio can be included in formulated diets for grouper to replace 12.5% to 25% of the animal protein sources. However, the results for the test diets may also have been due to other factors - the high fish meal content, inclusion of mussel meal, and increase in cod liver oil.