• Journal of Aquaculture
• /
• v.7 no.3
• /
• pp.165-175
• /
• 1994

Attempts were made to find out nitrogen and phosphorus loads to aquatic environment resulting from feeding Nile tilapia (Oreochromis niloticus). Two different size groups, small and large, were used. The average sizes of small and large tilapia were 65.2 g and 389.2 g respectively, and three kinds of commercial diets were used for each size. The 3 kinds of commercial diets for tilapia contained in average 33.8% crude protein ($5.4\%$ nitrogen) and $1.4\%$ total phosphorus. The load of nitrogen and phosphorus were measured by subtracting the amounts of nutrients retained in the body of fish from consumed nutrients. Sixty, five percentage of total feces was excreted within 24 hours after feeding at $23^{\circ}C$. Nitrogen content in the feces was higher in large fish than small ones. The apparent digestibility of dietary protein for small and large tilapia was $90.0\%$ and $89.7\%$, respectively. Availability of dietary phosphorus for small and large tilapia was $44.7\%\;and\;51.4\%$, respectively. The total load of nitrogen and phosphorus per 1 metric ton of tilapia production was 49.5kg and 6.3kg, respectively, for small ones with feed conversion ratio (FCR) of 1.4, and 61.3 kg and 13.4kg, respectively, for large ones with the FCR of 1.8. Nitorgen balance appeared that small and large tilapia excreted $7.1\%\;and\;9.9\%$ of consumed nitrogen through fecal-nitrogen and $55.5\%\;and\;62.3\%$ through urine and gills, retaining $37.4\%\;and\;27.8\%$ in the body, respectively. These results show that small fish pollute less than large fish, excreting less and retaining more nutrients in the body.

• Korean Journal of Ecology and Environment
• /
• v.37 no.1 s.106
• /
• pp.112-121
• /
• 2004

A study was performed to examine the effects of UV-disinfected reclaimed water on microorganism concentration during rice culture. Four treatments were used and each one was triplicated to evaluate the changes of microorganism concentrations: stream water irrigation (STR), biofilter effluent irrigation (BE), UV-disinfected water irrigation with dose of 6 mW ${\cdot}$ s $cm{-2}$ (UV-6), and UV-disinfected water irrigation with dose of 16 mW ${\cdot}$ s $cm{-2}$ (UV-16). The indicator microorganisms of interest were total coliform (TC), fecal coliform (FC), and E. coli. The biofilter effluent from 16-unit apartment sewage treatment plant was used as reclaimed water and flowthrough type UV-disinfection system was used. Concentrations of indicator microorganisms in the treatment plots ranged from $10^2$ to $10^5$ MPN/100 mL during 24 hours after irrigation in May and June, where initial irrigation water for transplanting reparation was biofilter-effluent without UV-disinfection. It implies that initial irrigation using only non-disinfected reclaimed water for puddling in paddy field can be health-concerned because of more chance of farmer's physical contact with elevated concentration of microorganisms. The concentrations of microorganisms varied widely with rainfall, and treatments using UV-disinfected water irrigation showed significantly lower concentrations than others and their levels were within the range of paddy rice field with normal surface water irrigation. The mean concentrations of STR and BE during growing season were in the range of 4 ${\times}\;10^3$ MPN/100 mL for TC, and 2${\times}\;10^3$ MPN/100 mL for FC and E, Coli, While mean concentrations of UV-S and UV-lS were less than 1${\times}\;10^3$ MPN/100 mL for all the indicator microorganisms. Overall, UV-disinfection was thought to be feasible and practical alternative for agricultural reuse of secondary level effluent in Korea.

• Journal of Life Science
• /
• v.15 no.5 s.72
• /
• pp.790-795
• /
• 2005

The effects of liquid culture of Coriolus (C) versicolor on weight gain, food intakes, food efficiency ratios, serum and hepatic lipid concentrations were investigated in male rats fed the high cholesterol diets. Eight weeks old Sprague-Dawley rats were given three different types of diet for six weeks, respectively: a control diet ($ 20\% fat +0.5 \% $ cholesterol), two kinds of C versicolor diet (control diet + $ 30\% or 40\%$C. versicozor in water) according to the levels of C. versicolor supplementation. The body weight gains of the rats fed $ 30\% or 40\% $ C. versicolor diets were lower than those in the rats fed the control diet. The food intake, food efficiency ratios, and liver, kidney, epididymal fat pad weights of the rats fed $ 30\% or 40\%$ C. versicoEer diets were similar to those of the rats fed the control diet. The concentrations of hepatic cholesterol and triglyceride in the rats fed $ 30\% or 40\% $ C. versicolor diets were significantly lower than those in the rats fed the control diet. The concentrations in serum total cholesterol, LDL-cholesterol, and atherogenic index ratios were significantly lower in the rats fed $ 30\% or 40\%$ C. versicolor diets compared to those fed the control diet. The HDL-cholesterol/total-cholesterol ratios was significantly higher in the rats fed $ 30\% or 40\% $ C. versicolor diets compared to those fed the control diet. The fecal excretion of total lipid and triglyceride in the rats fed $ 40\% $ C. versicolor diet was significantly higher than that of the rats fed the control diet. There were no significant difference found in the serum trigly-ceride, phospholipid and HDL-cholesterol concentrations among the experimental groups. These results showed that the C. versicolor feeding decreased the hepatic cholesterol, triglyceride, and the serum total cholesterol, LDL-cholesterol and atherogenic index, and increased the serum HDL-cholesterol/ total-cholesterol ratio of the rats.

• Korean Journal of Poultry Science
• /
• v.30 no.3
• /
• pp.151-159
• /
• 2003

Two experiments were carried out to evaluate the effects of feeding Aspergillus oryzae(AO) ferment on performance, intestinal microflora, serum components, ammonia generation and litter dampness in broiler chicks. In experiment I, three hundred sixty, one day old broiler chicks, Abor Acres, were fed 0 and 0.1% of Aspergiilus oryzae short conidia ferment(AOS) and 0.1% of Aspergillus oryzae long conidia ferment(AOL) for five weeks. In experiment II, three hundred sixty, one day old broiler chicks, Abor Acres were fed 0, 0.1 and 0.2% of Aspergillus oryzae long conidia ferment(AOL) for five weeks. In experiment I, growth rates were not statistically different among dietary treatments. AOS and AOL showed increased tendency in weight gain and feed intake compared to those of control, whereas feed conversion was not different. Litter dampness of AOS and AOL was also tended to decrease compared to that of control, but was not significantly different. Fecal ammonia gas generation was decreased in feeding AOS and AOL, and maintained 1/2 to 3/4 compared to the control. In serum metabolites, AOS and AOL increased glucose and calcium, and decreased total protein, blood urea nitrogen and total cholesterol. In experiment II, body weight of chicks fed 0.1 and 0.2% AOL were heavier than the control(P<0.05). Feed intake of chicks fed 0.1 and 0.2% AOL also were higher than the none, but feed conversion ratio was not different among treatments. Ileal and cecal microflora showed increased tendency in lactic acid bacteria compared to those of the control. Salmonella and E. coli were decreased in ileum of chicks fed 0.1 and 0.2% AOL. In conclusion, feeding AO ferment increased growth performance and improved intestinal microflora of broiler chicks and environments of broiler house.