• 한국양식학회지
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• 제15권1호
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• pp.49-60
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• 2002

Research on practices for improving water quality in channel catfish Ictalurus punctatus ponds was conducted at the Auburn University Fisheries Research Station, Auburn, Alabama, in 1998 and 1999. The objective of this two-year study was to determine better management practices to enhance water quality and improve production efficiency. In the first year, oxidation of bottom soil by drying, tilling, and applying sodium nitrate was performed (dry-till and dry-till with sodium nitrate treatments). The second year, based on the results obtained during the first year, precipitation of phosphorus (P) from water by applying gypsum was compared to the dry-till treatment (dry-till and dry-till with gypsum treatments). Control ponds were not subjected to bottom drying, tilling, sodium nitrate, or gypsum treatment. Channel catfish fingerings were stocked at 15,000/ha. In the first year, water in ponds from dry-till and dry-till with sodium nitrate treatments had lower concentrations (P < 0.01) of soluble reactive P, nitrate ($NO_{3} ^{-}) and nitrite ($NO_{2} ^{-}) nitrogen (N), total ammonia ($NH_3$) nitrogen, total suspended solids and turbidity, and higher values of pH, Secchi disk visibility, total alkalinity, total hardness, and calcium ($Ca^{2+}) hardness than water in control ponds. Ponds of the dry-till treatment also had lower concentrations (P < 0.01) of total P and total N than control ponds. Total fish production and survival rate did not differ among the treatments (P > 0.05). The findings suggested that drying and tiling pond bosoms between crops could achieve water quality improvement. Applying sodium nitrate to dry, tilled pond bosoms did not provide water quality improvement. In the second year, the treatment with the best results from the first year, dry-till, was compared with a dry-till with gypsum treatment. Enough gypsum was applied to give a total hardness of about 200 mg/L, and gypsum was reapplied as needed to maintain the hardness. Compared to the control, dry-till and dry-till with gypsum treatments had lower concentrations (P < 0.01) of total and soluble reactive P, total N, and total $NH_3$-N, and higher concentrations (P < 0.01) of dissolved oxygen. Ponds of the duty-till with gypsum treatment also had lower concentrations (P < 0.01) of chlorophyll $\alpha$, chemical oxygen demand, and total alkalinity than the control. Total fish production and survival rate did not differ (P > 0.05) among the treatments. These findings suggest that drying and tilling pond bosoms between crops and treating low hardness waters with gypsum could achieve water Quality improvement.

• Asian-Australasian Journal of Animal Sciences
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• 제31권10호
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• pp.1643-1653
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• 2018

Objective: This study investigated the effect of dietary crude protein (CP) supplementation on nutrient intake, nitrogen (N) utilisation, blood metabolites, ruminal fermentation and growth performance of young Holstein bulls. Methods: Twenty-one young bulls weighing $277{\pm}11.2kg$ were equally divided into three groups and were offered diets formulated with low CP (LCP; 10.21% CP and 4.22% rumen degradable protein [RDP]), medium CP (MCP; 12.35% CP and 5.17% RDP) and high CP (HCP; 14.24% CP and 6.03% RDP). Yellow corn silage was used as a unique forage source and was mixed with concentrate. This mixed feed was given ad libitum to the young bulls included in the study. Results: Results showed that CP intake, blood urea nitrogen, N intake, total N excretion and N balance increased linearly with an increase in dietary CP level (p<0.05). However, no significant difference was observed in nutrient digestibility among the bulls receiving the different diets. Ruminal pH (p<0.05) and ammonia nitrogen ($NH_3-N$) concentration (p<0.01) were significantly higher in the bulls receiving the MCP and HCP diets than in those receiving the LCP diet. The bulls receiving the HCP diet showed significantly higher ruminal bacterial protein level, propionate, acetate and total volatile fatty acid (TVFA) concentrations than bulls receiving the LCP diet (p<0.05). Moreover, dietary CP level exerted a significant positive effect on the final body weight, average daily gain and gain-to-feed ratio of the bulls (p<0.05). Conclusion: High dietary CP level is optimal for achieving maximum growth and high profitability without exerting a negative effect on the physiology of growing Holstein bulls.

• 멤브레인
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• 제28권1호
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• pp.31-36
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• 2018

본 연구에서는 막결합생물반응조(MBR)공법을 비롯한 하수고도처리공법에서 유입하수량의 변화에 따른 슬러지 특성 변화를 파악하고자 하였다. 일 1.5톤을 처리하는 모형실험시설에서 설계유량 대비 유입하수량을 100, 70, 40, 10%로 변화시켜가며 이에 따른 비탈질속도(specific denitrification rate)와 비질산화속도(specific ammonia oxidation rate)의 변화를 측정하였다. 각 공법의 폭기조에서 채취한 슬러지의 비질산화속도는 유입하수량 100% 조건에서 세 가지 공법 모두 유사한 값($0.10gNH_4/gMLVSS/day$)으로 측정되었다. 유입하수량이 70%에서 40%로 감소함에 따라 비질산화속도가 크게 감소하는 경향을 나타냈다. 비탈질속도 역시 유입하수량이 감소함에 따라 최대 50%가량 감소하였다. 유입하수량이 감소할수록 비탈질속도와 비질산화속도가 감소하는 경향을 나타냈으나 원수의 총질소 농도와 반응조 내 미생물 농도를 고려하면 질소제거율에 영향을 미칠 정도는 아니었다. 따라서 유입하수량이 감소하는 경우에도 반응조 내 미생물 농도를 높게 유지할 수 있다면 안정적인 질소 제거가 가능할 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권4호
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• pp.536-542
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• 2007

The responses of whole body protein and glucose kinetics and of nitrogen (N) metabolism to non-protein energy intake (NPEI) were determined using an isotope dilution approach and measurement of N balance in three adult male goats. The diets containing 1.0, 1.5 and 2.0 times ME maintenance requirement, with fixed intake of CP (1.5 times maintenance) and percentage of hay (33%), were fed twice daily for each 21 d experimental period. After an adaptation period of 11 d, N balance was determined over 3 d. On day 17, whole body protein synthesis (WBPS) and glucose irreversible loss rate (ILR) were determined during the absorptive state by a primed-continuous infusion of [$^2H_5$]phenylalanine, [$^2H_2$]tyrosine, [$^2H_4$]tyrosine and [$^{13}C_6$]glucose, with simultaneous measurements of plasma concentrations of metabolites and insulin. Ruminal characteristics were also measured at 6 h after feeding over 3 d. Nitrogen retention tended to increase (p<0.10) with increasing NPEI, although digestible N decreased linearly (p<0.05). Increasing NPEI decreased (p<0.01) ammonia N concentration, but increased acetate (p<0.05) and propionate (p<0.05) concentrations in the rumen. Despite decreased plasma urea N concentration (p<0.01), increased plasma tyrosine concentration (p<0.05), and trends toward increased plasma total amino N (p<0.10) and phenylalanine concentrations (p<0.10) were found in response to increasing NPEI. Increasing NPEI increased ILR of both glucose (p<0.01) and phenylalanine (p<0.05), but did not affect ($p{\geq}0.10$) that of tyrosine. Whole body protein synthesis increased (p<0.05) in response to increasing NPEI, resulting from increased utilization rate for protein synthesis (p<0.05) and unchanged hydroxylation rate of phenylalanine ($p{\geq}0.10$). These results suggest that increasing NPEI may enhance WBPS and glucose turnover at the absorptive state and improve the efficiency of digestible N retention in goats, with possibly decreased ammonia and increased amino acid absorption. In addition, simultaneous increases in WBPS and glucose ILR suggest stimulatory effect of glucose availability on WBPS, especially when sufficient amino acid is supplied.

• Asian-Australasian Journal of Animal Sciences
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• 제7권3호
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• pp.413-419
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• 1994

Mold growth decreased nutritive value of wheat straw (WS). Mold increased DM (94 vs 98%) and ADF (51 vs 56%) contents and had no effect on natural detergent fiber (NDF). Crude protein and N values were decreased in moldy wheat straw, Mold increased insoluble N content of wheat straw (WS) from 21 to 27%. Ammoniation increased the CP of nonmoldy straw from 3.8 to 8.3% and moldy straw from (3.3 to 6.2%). Aspergillus and zygomycetes fungal species were most prevalent and total numbers were higher on moldy straw. Ammoniation decreased total numbers of fungal spores on nonmoldy and moldy WS. Ammoniation of moldy WS increased (p < 0.10) feed in take (1.8%) as compared with nonmoldy, ammoniated, nonmoldy and moldy WS. Steers fed moldy WS had lowest (p < 0.10) feed intake (1.3% of BW daily) compared with other diet. There was little difference (p < 0.10) in intake of nonammoniated vs. ammoniated WS. Steers fed moldy straw lost 6 kg BW. Ammoniated, nonmoldy straw elevated Blood Urea Nitrogen (BUN) (10.5 mg/dl). Alkaline Phosphatase (ALK) was greater in steers fed moldy VS nonmoldy straw (148 VS 95 U/liter. p < 0.10).

• Membrane and Water Treatment
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• 제6권1호
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• pp.15-26
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• 2015

The compact structure and high-quality effluent of membrane bioreactors make them well-suited for decentralized greywater reclamation. However, the occurrence of membrane fouling continues to limit their effectiveness. To address this concern, a unique membrane module configuration was developed for use in a decentralized greywater treatment system. The module featured local aeration directly below a series of inclined membrane bundles, giving the overall module a twisted appearance compared to a module with vertically orientated fibres. The intent of this design was to increase the frequency and intensity of collisions between rising air bubbles and the membrane surface. Material related to the construction of custom-fit modules is rarely communicated. Therefore, detailed design and assembly procedures were provided in this paper. The twisted module was compared to two commercially available modules with diverse specifications in order to assess the relative performance and marketability of the twisted module with respect to existing products. Contaminant removal efficiencies were determined in terms of biochemical oxygen demand, chemical oxygen demand, ammonia, total nitrogen, total phosphorus, and turbidity for each module. Membrane fouling was monitored in terms of permeate flux, transmembrane pressure, and membrane resistance. Following 168 h of operation, the twisted module configuration demonstrated competitive performance, indicating good potential for further development and commercialization.

• Asian-Australasian Journal of Animal Sciences
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• 제18권1호
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• pp.22-26
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• 2005

Four male crossbred beef steers about 2 years old were used in a 4$\{times}$4 Latin square design to investigate the effect of pelleted sugarcane tops on voluntary feed intake, rumen fermentation and digestibility of nutrients. Experimental treatments were; Control (dried-chopped sugarcane tops (DCST)); PS1 (Pelleted sugarcane tops at 1 cm of diameter); PS2 (Pelleted sugarcane tops at 2 cm of diameter) and PS3 (Pelleted sugarcane tops at 3 cm of diameter). Roughage intake and total dry matter intake were 1.59, 1.62, 1.61, 1.63% BW and 2.09, 2.12, 2.11 and 2.13% BW in control, PS1, PS2 and PS3 treatments, respectively (p<0.05). Digestibility of DM, OM and CP were similar in control and PS3 treatment but there was significant difference (p<0.05) between control and PS1, PS2 treatments. Digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were 52.89, 50.01, 50.05 and 50.56% and 41.91, 39.96, 39.91 and 39.69% in control, PS1, PS2 and PS3, respectively (p<0.05). Total volatile fatty acids concentrations in rumen contents was 67.68, 65.93, 66.15 and 66.67 mM in control, PS1, PS2 and PS3, respectively (p<0.05). Even though, concentrations of acetate and butyrate (%) were significant different (p<0.05) but concentration of propionate (%) was not affected by treatments (p>0.05). Rumen pH, ammonia nitrogen and plasma urea nitrogen were significantly different (p<0.05) among treatments. From this experiment, it was found that dried-chopped sugarcane tops increased digestibility of nutrients whereas pelleted sugarcane tops increased feed intake in beef cattle. However, pelleted sugarcane tops at 3 cm of diameter did similar result in digestibility and rumen parameters with DCST. Therefore, it could be concluded that pelleting sugarcane top is an alternative way to improve the quality of sugarcane tops for use as ruminant roughage source.

• Asian-Australasian Journal of Animal Sciences
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• 제24권6호
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• pp.810-817
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• 2011

A feeding trial was conducted to study the effect of tannin rich Pakar (Ficus infectoria) leaves on microbial profile, rumen fermentation and nutrient utilization in goats. Eight goats divided in two groups were fed pakar leaves (experimental group) and green oats (control group) as sole roughage source along with a fixed quantity of concentrate mixture for a period of 3 months. Two metabolic trials of six days duration were conducted after 30 and 90 days of experimental feeding. The dry matter intake was significantly higher (p<0.05) and digestibility's of DM, OM, CP, EE, NDF and ADF were reduced in experimental as compared with the control group. The TDN intake was similar (236.52 vs. 240.39 g/d) in both the groups. All the animals were in positive nitrogen balance. The concentration of ammonia nitrogen, TVFA, lactic acid and activities of xylanase and protease were reduced in pakar leaves fed goats. The rumen microbial profile as obtained by MPN technique showed no change in total bacterial population but total fungi and cellulolytic bacteria were reduced (p<0.05), whereas, tannin degrading/tolerant bacteria increased with the feeding of pakar leaves. Real time PCR data revealed a decrease in Ruminococcus flavefaciens, an increase in methanogens and no change in the Fibrobacter succinogenes population by feeding of pakar leaves.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.371-378
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• 2011

Juvenile red seabream (mean body weight 29.0 g) were reared in recirculating culture systems with three different biofilter media, sand (SF), polystyrene microbeads (PF), and Kaldnes beads (KF). The efficiencies of the three different biofilter media were also tested. The SF was fluidized, and the PF and KF were trickled. All treatments were duplicated. The volumetric removal rates of total ammonia nitrogen by SF, PF, and KF were 193.8, 183.9, and 142.6 g $m^{-3}day^{-1}$, respectively, and those of nitrite nitrogen ($NO_2$-N) were 113.4, 105.9, and 85.8 g $m^{-3}day^{-1}$, respectively. The TAN and $NO_2$-N removal rates of KF were lower than those of SF and PF (P < 0.05), but there was no significant difference in these rates between SF and PF (P > 0.05). Among the biofilters used, only KF showed total suspended solid (TSS) removal capacity. The TSS removal efficiencies of SF and PF were negative. The growth rates of fish in SF were significantly higher than those in KF but not higher than those in PF. There was no difference in growth rate between fish in PF and KF. The specific growth rate and feed conversion efficiency of red seabreams in KF were lower than those in SF and PF, but there were no significant differences between SF and PF. These results indicate that sand and polystyrene microbeads are recommended for red seabream culture in a recirculating system.

• 한국축산시설환경학회지
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• 제6권2호
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• pp.73-81
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• 2000

A two-phase anaerobic digestion system for the treatment of swine waste was constructed in a commercial hog farm. The digester system was composed of 4 major units; slurry storage pit, acidogenic digester, methanogenic digester and sedimentation pit. A biogas boiler unit was also attached to maintain the digester temperature of 37$^{\circ}C$. Substrate lading was made with 2hr-interval by pumping about 2.1$m^3$ of slurry type swine waste from the slurry pit into the acidogenic digester, which corresponds to hydraulic retention time of 4 days for the acidogenic digester and of 11 days for the methanogenic digester. Digester temperature were well maintained as the set temperature of 37$^{\circ}C$ in the methanogenic digester, while the temperature in the acidogenic digester showed around 34$^{\circ}C$. pH also showed a steady-state results of 7.3 in the acidogenic digester and of 7.6 in the methanogenic digester during the operation period. Average biogas production rate was 0.66$m^3$/$m^3$ digester volume. Reduction rate of total solid and volatile solid were 42.8% and 5.8%, respectively. Total nitrogen and ammonia nitrogen were not reduced during the anaerobic fermentation, however, most of VFAs seemed to be converted to the biogas,. These fermentation performance data may suggest that he newly developed a two-phase anaerobic digester for the swine waste treatment worked so successfully.