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    Economic analysis of tilapia pond culture in Iloilo
    Arellado, Emily A. (Division of Social Sciences, College of Arts and Sciences, University of the Philippines in the Visayas, 1997-03)
    This paper analyzed the factors affecting production of tilapia pond culture in Iloilo using the production function approach. The study used primary and secondary data. Primary data were gathered from a survey of actual operations of 30 tilapia farmers in Iloilo. Secondary data were taken from the Department of Agriculture in Sta. Barbara, Iloilo, the SEAFDEC and UPV libraries. The production function was specified using the Cobb-Douglas function to identify and explain the factors affecting variations in the output of tilapia. The explanatory variables included in the analysis were: fingerlings stocked (X1), inorganic fertilizers (X2), organic fertilizer (X3), supplementary feeds (X4), farm size (X5), hired labor (X6), miscellaneous operating costs (X7), number of years in tilapia farming (X8) and age of pond (X9). There were six variables found significant in explaining tilapia 'production namely; fingerlings stocked, inorganic' fertilizer, organic fertilizer, farm size, hired labor and age of pond. The F—statistic rejected the null hypothesis which states that no explanatory variables help to explain variations in the dependent variable. Therefore, the alternative hypothesis was accepted that at least one or more of the independent variables affect production. The R2 showed that 92 percent of the variations of the explanatory variables explained the variations in the independent variables. This implies that there exists a relationship between the independent and dependent variables. Fingerlings stocked, inorganic fertilizer and hired labor were used inefficiently by the tilapia farmers. The use of fingerlings stocked should be increased while the use of inorganic fertilizer, organic fertilizer and hired labor should be reduced, if the maximum net returns are to be realized.
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    Quality changes in Tilapia (Oreochromis niloticus) after delayed icing and subsequent storage in ice.
    Saluan-Abduhasan, Fathma (University of the Philippines Visayas, 1985-04)
    Quality changes in tilapia (Oreochromis niloticus) iced directly on harvesting were compared to those occurring when icing was delayed. Chemical and sensory examinations showed that the shelf life of tilapia was 26 days when iced immediately. 20 days and 15 days with 4 and 8 hours delay, respectively.Fish kept at ambient temperature for 12 hours were rejected after one day in ice. These results suggests that for every hour delay in icing the effective shelf life is reduced by approximately one day up to the 8th hour delay. Total volatile nitrogen values increased with storage time. Likewise, K-value and hypoxanthine values increased as storage time increased. The initial bacterial load ranged from 103- 104 cfu/g of fish with H2S-producers count of less than 100 cfu/g of fish. At rejection, the microbial load was 108-109 cfu/g of fish with H2Sproducers count of 106-107 cfu/g. The typical off odours of naturally spoiling fish have been reproduced in blocks of sterile muscle by organisms such as Alteromonas putrefaciens, Pseudomonas sp, Pseudomonas maltophilia, Pseudomonas flourescens and pseudomonas stutzeri.
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    Growth performance, feed utilization and survival against stress test of juvenile Nile tilapia Oreochromis niloticus fed with lactic acid bacteria (lab) Pediococcus acidilactici
    So, April Dawn P. (University of the Philippines Visayas, 2016-06)
    The present study evaluated the growth performance, feed utilization and survival against stress test of Nile tilapia, Oreochromis niloticus fingerlings (mean initial average body weight 0.39g ± 0.01) fed with commercial probiotics. The experimental design was randomized, with four treatments and four replicates: Treatment 1 (control) with 0g kg-1 probiotics inclusion, Treatment 2 with lg kg1 probiotics inclusion, Treatment 3 with 2g kg'1 probiotics inclusion and Treatment 4 with 4g kg'1 probiotics inclusion. Three hundred and twenty fingerlings were distributed in 16 50L containers and fed for 40 days. Differences in the mean values of total weight were found at the end of the experiment. After 40 days of feeding trial, percent weight gain (%WG), specific growth rate (SGR) and and feed conversion ratio (FCR) was significantly high (P < 0.05) in treatments with probiotics compared to probiotic-free treatments; no differences on survival rate (SR) was observed among dietary treatments. The best growth performance and feed conversion was observed in fishes fed with 4g kg'1 probiotics inclusion. Challenge was done immediately after the period of application. The stress challenge test was done to the experimental animals by exposure to oxygen deficient water or asphyxia. No significant difference (P < 0.05) on SR was observed after 3 hours exposure to asphyxia. It could be concluded that probiotics can improve growth performance and feed utilization. However, further studies are recommended to assess the effects of probiotics to fish when exposed to asphyxia.
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    Quality changes in Tilapia (Oreochromis niloticus) after delayed icing and subsequent storage in ice
    Saluan-Abduhasan, Fathma (College of Fisheries, University of the Philippines in the Visayas, 1985-04)
    Quality changes in tilapia (Oreochromis niloticus) iced directly on harvesting were compared to those occurring when icing was delayed. Chemical and sensory examinations showed that the shelf life of tilapia was 26 days when iced immediately. 20 days and 16 days with 4 and 8 hours delay, respectively. Fish kept at ambient temperature for 12 hours were rejected after one day in ice. These results suggest that for every hour delay in icing the effective shelf life is reduced by approximately one day up to the 8th hour delay. Total volatile nitrogen values increased with storage time. Likewise, K-value and hypoxanthine values increased as storage time increased. The initial bacterial load ranged from 103- 104 cfu/g of fish with H2S-producers count of less than 100 cfu/g of fish. At rejection, the microbial load was 108~109 cfu/g of fish with HgS-producers count of 106-107 cfu/g. The typical off odours of naturally spoiling fish have been reproduced in blocks of sterile muscle by organisms such as Alteromonas putrefaciens, Pseudomonas sp, pseudomonas maltophilia, Pseudomonas flourescens and pseudomonas stutzeri.