UPV Theses and Dissertations
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Item Effects of high and low protein diets on the gut evacuation rate of Tilapia niloticaAndrada, Bryan Andrew S. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1999-03)Gut evacuation rate of young Nile tilapia, Tilapia nilotica fed commercial pelleted diets containing high or low protein diet were determined in the laboratory. The decline in gut fullness of the fish with time was examined at low and high protein diets. Two mathematical models were used to express the decline in gut fullness of the fish with time. Fish fed the low protein diet followed more closely the linear model while those fed the high protein diet followed the logarithmic model. The level of protein resulted in different gut evacuation rates (GER), expressed as coefficients b of the gut fullnesstime curve. GER values were higher in either linear or logarithmic models for fish fed low protein diet than for those fed high protein diet.Item Comparison between commercial pellets and golden apple snail pellets as food for Tilapia nilotica fingerlingsArboleda, Daphne A. (Dision of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1997-04)The viability of Golden apple snail as food for Tilapia nilotica was determined by comparing it with commercial pellets. The experiment was conducted on February 3, 1997. The two treatments had three replicates each with a stocking density of 15 fingerlings each. Comparison of growth curves showed that fingerlings fed with commercial pellets grew significantly (P< 0.01) faster than those fed with golden apple snail pellets. The computed FCR was also greater for commercial pellets. The results suggest that golden apple snail alone does not promote efficient growth in Tilapia nilotica fingerlings. Thus it is recommended that golden apple snail be combined with other food ingredients to enable its efficient utilization as a protein source.Item Quality changes in Tilapia (Oreochromis niloticus) after delayed icing and subsequent storage in ice.Saluan-Abduhasan, Fathma (University of the Philippines Visayas, 1985-04)ABSTRACT 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, V 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.Item Effects of dietary pH on growth performance and feed utilization of nile tilapia (Oreochromis niloticus)Fabay, Ryan V. (University of the Philippines Visayas, 2020-06)ABSTRACT Two feeding trials were conducted to investigate the effects of dietary pH (pH 2.5, 3.7, 4.6, 5.7-control, pH 7.0, and pH 8.0) and dietary acid source (acetic acid, citric acid, hydrochloric acid and control-no acid) on growth rate and feed utilization efficiency of the Nile tilapia fry. In addition, attractability indices of the diets at different pH and dietary acid sources were determined. Results of the first feeding trial showed that the feed with pH adjusted to 4.6 resulted in increased growth rate and improved feed utilization efficiency in the Nile tilapia. In the second feeding trial, the use of either hydrochloric, citric or acetic acid in adjusting the pH to the optimal 4.6 did not affect the growth performance of the fish. This study demonstrated that pH and not actually the kind of acid diet promoted growth and efficiency in the Nile tilapia fry. Furthermore, this study provides new information on the use of acid in aquaculture as feed additive for tilapia fry, which can be added to fish feed literature.Item Growth performance, feed utilization and survival against stress test of juvenile Nile tilapia Oreochromis niloticus fed with lactic acid bacteria (lab) Pediococcus acidilacticiSO, April Dawn P. (University of the Philippines Visayas, 2016-06)ABSTRACT 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.