• Journal of Aquaculture
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• v.20 no.3
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• pp.178-183
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• 2007

We investigated the effect of salinity decrease, food supply and color of the rearing tank on the growth and survival of Amphiprion polymnus larvae. White tanks had the highest survival rate, followed by transparency, black and blue tanks(P<0.05). The transparency tank had the best growth, followed by black tank, white and blue tanks(P<0.05). Daily food intakes of larvae with $5.1{\sim}10.0mm$ in total length were $36.8{\sim}429.3$ Artemia nauplii. When salinity was lowered 5 psu per week from 32 psu, all the larvae died under salinity condition 17 psu. In lowered 2 psu per 3 days, its all died at 16 psu.

• Journal of Animal Environmental Science
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• v.8 no.1
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• pp.25-34
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• 2002

In view of increasing environmental pollution, the organic farming in animal production is becoming increasingly urgent. The problems of veterinary medicine have not diminished through the most dangerous epidemic diseases. Organic farming attempts to function in harmony with the environment. The first criterion of the organic farm is that the animal must be self-sustaining. Their food must be produced to a large extent on the farm. The position of ruminants in biological systems is determined by the fact that this group of farm animals is provided with a digestive system which optimizes the utilization of the products of gut microfloral fermentation. The cattle do not require large amounts of concentrate feeling nor gross ugly farm building for intensive rearing. The economic profitability of a cow depends. on the first instance, on the level of milk production and the number of lactations. The length of life is an important factor since the tilde to maturing is relatively high in a cow. The result is that dairy cows in organic farming have greater length of live, and produce more milk in their life time than the shorter lived high input cow. This paper. therefore, discussed the problems of modern cattle farming and development trends of organic farming in Germany and Korea.

• Korean Journal of Ichthyology
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• v.19 no.2
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• pp.128-131
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• 2007

Head length, snout length, postorbital length, and eye diameter were measured in 209 brown croaker, Miichthys miiuy, ranging from 3.0 to 650.0 mm in total length (TL). All of the four head dimensions were regressed against the TL respectively and were increased linearly with the relative size of the head. The determination coefficients ($r^2$) ranged from 0.9823 to 0.9916, and all analysis of variance values were significant (P<0.0001). Those results suggest that these head dimensions may be useful indicators for detecting morphological deformities or for individual and population growth histories to aid in the successful rearing of brown croaker fingerlings.

• Korean Journal of Ichthyology
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• v.22 no.3
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• pp.195-200
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• 2010

A large volume of hatching jar was tested whether it is an effective to hatch fertilized eggs of Pacific cod. The volume of hatching jar did not show any significant differences in survival of the fertilized eggs; 48.3% for the jar of 15 L and 50.4% for that of 42 L. Survival rate of the fertilized eggs in a large volume of hatching jar ranged from 40.0 to 71.2%, which was higher than those of conventional small circular tank. A higher survival could be achieved even though stocking density of fertilized eggs was as high as 5,000 mL/jar. Consequently, the tested hatching jar allowed for incubation of a greater number of eggs with higher survival rate in a much smaller space. In addition, it reduces costs and manpower, and requires a relatively small amount of water per individual unit (6,700 mL/min), and provides a way to incubate multiple rearing groups in a quarantine environment.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.11
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• pp.1714-1720
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• 2018

Objective: This study was conducted to analyze the effects of stocking density on growth and carcass quality, and behavior of Hanwoo cattle to conform with global trends, targeting animal welfare production through the practice of environmentally friendly condition. Methods: Thirty six steers were randomly assigned to three treatment groups (C: 5 heads, T1: 4 heads, T2: 3 heads) and reared in separate pens with a constant stocking density of $50m^2$ (C: $10m^2/head$, T1: $12.5m^2/head$, T2: $16.67m^2/head$) per group from 12 to 30 month of age. Growth performance, behavior and carcass quality traits of each steer were recorded and compared between the treatment groups. Results: In general, the average daily gain during the fattening period was lower in group T2 than in T1 and the control groups. However, carcass weight and dressing percentage was lower in the control group than in T1 or T2 groups (p<0.05). Also, marbling score at 30 months of age was the lowest in the control group (p<0.05), while the three heads group (T2) had the greatest longissimus muscle area and marbling score (p<0.05). The behavior of walking time was the greatest in T2 group, while self-grooming and fighting occurred with the most frequency in the control group (p<0.05). Conclusion: Our results show that the steers in more spacious stocking density had better carcass quality and wellbeing related behaviors, indicating that a lower density has a positive effect on raising management and carcass quality. Thus it is a need to install appropriate pens fitted to welfare-oriented management practices from growing to fattening period in Hanwoo cattle.

• Development and Reproduction
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• v.18 no.1
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• pp.33-41
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• 2014

We investigated the process of yolk absorption in Korean rose bitterling, Rhodeus uyekii, and determined the changes in its morphometric characteristics. The R. uyekii from 1 days post hatching (DPH) to 21 DPH, the eye diameter (ED) was 5.4 at 5 DPH. Thereafter, the ED/total length (TL) ratio increased to 10.7 at 21 DPH (p<0.05). The yolk length (YL) decreased from 95.4 to 1.1 by 21 DPH, and this rate of decrease was greater than that for any other dimension (p<0.05). 12 morphometric dimensions/TL for the R. uyekii were measured at each sampling day from 21 DPH to 170 DPH. At just hatching, the average TL and BW were $6.1{\pm}0.09mm$ and $4.9{\pm}0.07mg$, respectively. At 53 DPH, the average TL was $12.9{\pm}0.28mm$ and the average BW was $14.7{\pm}0.72mg$; the total length growth equation was $TL=5.507e^{0.038t}$ ($R^2=0.916$). Further, the body weight growth equation was $BW=3.3647e^{0.0296t}$ ($R^2=0.9354$). The dimensions with regard to body depth showed the greatest growth rates in the external characteristics of the fish (p<0.05). The patterns of the morphometric characteristics measured in this study can be classified in three ways. The patterns were shown to be increased (y=0.0992x+12.07, $R^2=0.8333$), decreased (y=-0.0569x+42.029, $R^2=0.8395$) or maintained (y=0.005x+18.263, $R^2=0.3678$) from 21 DPH to 170. These results will provide useful indices for the successful rearing of the R. uyekii.

• Development and Reproduction
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• v.18 no.1
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• pp.13-23
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• 2014

This study is conducted to monitor the morphological developmental features of the egg development, larvae and juvenile of Epinephelus septemfasciatus, the fertilized eggs were gotton using artificial insemination. Matured parents are collected from marine caged fish farms in Geomun-ri, Samsan-myeon, Yeosu-si, Jeollanamdo Korea in June 2012. The fertilized eggs were pelagic eggs containing one oil globule, and measured 0.81~0.89 mm ($0.85{\pm}0.04mm$, n=50) in diameter. In regard to rearing environment, the water temperature is $21.0{\sim}23.0^{\circ}C$ and the salinity is 32.0~33.2‰. Hatching was observed from 48 hours after fertilization, the mouth and anus of prelarvae was not opened but had egg yolk at newly hatched. 4 days after hatching, the mouth and anus of postlarvae was opened and began to eat Rotifer and was measured 2.40~2.49 mm ($2.45{\pm}0.03mm$ n=10) in total length. 12 days after hatching, postlarvae was measured 3.77~4.67 mm ($4.27{\pm}0.33mm$) in total length, its the second pole tide of dorsal fin and the first pole tide of pelvic fin was extended longitudinally. 71 days after hatching, juvenile was measured 40.5~45.4 mm ($42.6{\pm}2.04mm$) in total length. Seven bands were observed in body, and pole tides of dorsal and pelvic fins were shortened.

• Journal of Veterinary Clinics
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• v.26 no.5
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• pp.423-428
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• 2009

There were outbreaks of canine distemper in Korea from the late 1990's to the early 2000's even though modified live CDV vaccines had been used as the same way as before. The present study was undertaken to investigate the levels of neutralizing antibodies in the Korean dog population, and the factors associated with the levels, with special reference to the vaccination history of the dogs. A total of 772 serum samples were from clinically healthy dogs with over one year old throughout the Korea from January 2003 to April 2004. Details on the sex, breed, age, vaccination status and disease histories were recorded. The level of neutralizing antibodies titer was determined with a modified version of the microneutralization test. Titers over 16 were classified as protective CDV antibody titers. The overall rate of adult dogs with protective antibody titers was 96.0%. The dogs with protective antibody titers varied depending on age, sex, rearing environment and vaccination status. Because the majority of healthy adult dogs in Korea had adequate serum antibody titers against CDV and the immunity provided by the vaccinations is claimed to last for several years, annual revaccination protocol for CDV in adult dogs should be reconsidered.

• Korean Journal of Ecology and Environment
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• v.44 no.1
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• pp.95-101
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• 2011

Present study aimed to investigate morphological change and gene expression in the gill of Cyprinus carpio after exposure against muddy water caused by riverbed disturbance with various rearing condition. The gill of C. carpio showed abnormal shapes in its secondary lamellae and a rough surface with impure debris after exposed to muddy water for 80 days. In addition, the gills showed the edema, the exfoliation of epithelial cell, and the fusion of the secondary lamellae. Using 20 ACPs, 24 differentially expressed genes (DEGs) exposed to muddy water for 80 days were identified. 17 genes among them were up-regulated, while 7 genes were down-regulated in preterm deliveries. A BLAST searches revealed that 3 genes were revealed known genes as calcium transporter 1 (TRPV6) mRNA, macha mRNA for putative puroindoline b protein, and Efnb3 protein-like. Therefore, it is considered that Efnb3 gene from gill would be a useful indicator for neurobehavioral changes in fish influenced by muddy water.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.10-17
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• 2013

History of Instream Flow Incremental Methodology (IFIM) Following the large reservoir and water development era of the mid-twentieth century in North America, resource agencies became concerned over the loss of many miles of riverine fish and wildlife resources in the arid western United States. Consequently, several western states began issuing rules for protecting existing stream resources from future depletions caused by accelerated water development. Many assessment methods appeared during the 1960's and early 1970's. These techniques were based on hydrologic analysis of the water supply and hydraulic considerations of critical stream channel segments, coupled with empirical observations of habitat quality and an understanding of riverine fish ecology. Following enactment of the National Environmental Policy Act (NEPA) of 1970, attention was shifted from minimum flows to the evaluation of alternative designs and operations of federally funded water projects. Methods capable of quantifying the effect of incremental changes in stream flow to evaluate a series of possible alternative development schemes were needed. This need led to the development of habitat versus discharge functions developed from life stage-specific relations for selected species, that is, fish passage, spawning, and rearing habitat versus flow for trout or salmon. During the late 1970's and early 1980's, an era of small hydropower development began. Hundreds of proposed hydropower sites in the Pacific Northwest and New England regions of the United States came under intensive examination by state and federal fishery management interests. During this transition period from evaluating large federal reservoirs to evaluating license applications for small hydropower, the Instream Flow Incremental Methodology (IFIM) was developed under the guidance of the U.S. Fish and Wildlife Service (USFWS).