• Korean Journal of Poultry Science
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• v.42 no.3
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• pp.257-265
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• 2015

Heat conditioning at an early age has been known to help chickens cope with heat stress later in life. The present study was conducted to determine the effects of heat conditioning at 5 days of age in broilers repeatedly exposed to high ambient temperature later in life. A total of 256 day-old Arbor Acre boiler chicks were housed in two identical rooms with a 23-h light/1-h dark cycle and provided with feed and water ad libitum. At 5 days of age, the birds in one room were exposed to $37^{\circ}C$ for 24 hours, while those in the other room served as controls. On day 21, half of the birds in each room were moved into the other room so that each room contained both control and heat-conditioned birds. After a 7-day adaptation period, the birds in one room were exposed to high ambient temperature ($21^{\circ}C{\rightarrow}31^{\circ}C$) for 3 days, whereas those in the other room were kept at normal temperature. The same 3-day exposure to high ambient temperature was repeated two weeks later. Hence, there were four treatment groups (CON+CON: control+control; CON+HS: control+high ambient temperature; HC+CON: heat conditioning+control; and HC+HS: heat conditioning+high ambient temperature). Repeated heat stress resulted in decreased feed intake, water intake, body weight gain, and spleen weight (p<0.05) and increased rectal temperature (p<0.05), mortality, and plasma corticosterone concentrations. The relative weight of the spleen was increased in the heat-conditioned group (p<0.05). Plasma biochemicals were also influenced by high temperature. Thus, no beneficial effects of heat conditioning at an early age were detected in broilers repeatedly exposed to high ambient temperature later in life.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.512-519
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• 2012

The current study was conducted to investigate the effect of macsumsuk and herb resources on the performances and meat quality of broiler chickens. Six hundreds (600) broiler chickens were randomly allocated into four groups (4 groups${\times}$50 chickens/group${\times}$3 replica), Control, Treatment 1 (T1; 0.3% macsumsuk), Treatment 2 (T2; 0.3% herb resources), and Treatment 3 (T3; 0.3% macsumsuk + 0.3% herb resources) and fed for 5 wk. T2 group showed higher total body weight gain and average daily gain of 1,812.5 g and 51.79 g, respectively, than the other groups. Control group showed the highest (p<0.05) mortality (8%) and total blood cholesterol (111.8 mg/dL) among experimental groups. T3 group (6.71 mg/dL) showed the highest (p<0.05) while control group (4.50 mg/dL) showed the lowest (p<0.05) in blood IgG levels. Cooking loss was 17.08, 16.14, 16.55, and 15.25%, shear force value was 1.91, 1.52, 1.55, and 1.47 $kg/cm^2$, and water holding capacity (WHC) was 54.40, 55.97, 56.01, and 55.70% for Control, T1, T2, and T3, respectively. Cholesterol contents in breast meat of Control (88.91 mg/100 g) chickens showed the highest (p<0.05) levels comparing to either T1 (83.59 mg/dL), T2 (82.41 mg/dL), or T3 (80.81 mg/dL) chickens. In conclusion, the current study implies that feeding macsumsuk and herb resources to broiler chickens could decrease cholesterol contents in breast meat.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.3
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• pp.187-198
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• 1970

The author succeeded in rearing the young blue crab from the first stage of zoe ato the true crab shape, and during this time he observed their growth and metamorphosis. The relationships between the number of eggs carried by female crabs (E) and the carapace width (C) and body weight (W) are shown as follows: E= 27.9049C-281.8155, E=0.5682 W-116.4606. There are five zoeal stages and a megalopa in the complete larval development of the blue crab. Water temperature in rearing aquaria ranged from 21.4 to $25.2^{\circ}C$. The duration of each zoeal stage was two days on the average. After the fifth moulting, the zoea becomes megalopa and 5 to 6 days later the megalopa moults and develops into the first stage of adult crab shape. The carapace width of megalopa measured about 1.70 mm and the carapace length, from the tip of the rostrum to the posterior dorsal margin of the carapace, was about 2.78 mm on the average. The carapace width and length of the first crab, 18 days after hatching, measured about 4.48 mm and 2.62 mm respectively. After two days, the first crab moulted and grew into the second crab with about 6.47 mm in carapace width and 4.66 mm in carapace length. The larval rearing in the outdoor tank shelved better results than in the indoor aquarium. The highest mortality occurred when the first stage of zoea moulted into the second stage. Percentage of crabs which survived, from the first crab to the ninth crab stages, was about $55\%$. The relationships between rearing days (D) and the carapace width (C), carapace length (L) and body weight (W) of the crab stages during 40 days of rearing are shown as follows. Carapace width, Indoor: C=1.1250D+1.7227 Outdoor C=1.3465D -0.2449 Carapace length, Indoor: L=0.6654D+1.6712 Outdoor: L=0.7893D+0.6919 Body Weight, Outdoor: $$W=1.15e^{0.12423D}$$ Indoor: $$W=6.759\times10^{-2}D^{1.2598}$$ (9-19 day old crabs) Outdoor: $$W=4.136\times10^{-2}D^{1.6024}$$ (21-40 day old crabs) During the crab stage, the following relationships between the number of moulting times and the carapace width (C), carapace length (L) and body weight (W) were found as follows: $$C=5.2e^{0.28119N}$$ $$L=3.65e^{0.26372N}$$ $$W= 0.14e^{0.7037N}$$ The relationships between the carapace length (L) and the carapace width (C) and body weight (W) of the crab stages are shown as follows: Carapace length, mm Formula 2.62-27.17 L=1.6864C-1.0387 7.47-18.53 $$W=9.367\times10^{-5}C^{3.5567}$$ 22.11-27.17 $$W=3.406\times10^{-5}C{3.8571}$$

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.6
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• pp.514-519
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• 2012

Abalone culture is one of important coastal fisheries off Wando in the southeast coast of Korea. Since cage culture for abalones was popularized, Understanding of temperature variation, which is important to raise abalones and to prevent their mass mortalities, is necessary. We analyzed temperature data from 2005 to 2009 obtained at Sinji-do and Cheongsan-do off Wando. Sinji-do, which is relatively close to land, had yearly wide range of temperature and rate of temperature variation. It is likely to be caused by heating of solar radiation in summer and cooling in winter at the shallow area. Rate of temperature variation in autumn was higher than that in spring. In summer short term variation of temperature corresponding tidal period was distinguished clearly. Diurnal temperature range, abrupt temperature change, was larger open sea. Comparison between temperatures of two stations and favorable raising conditions of abalones showed that Cheongsan-do, located out to sea, appears to be more appropriate than Sinji-do.

• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.128-133
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• 2017

To determine the optimum water temperature (a temperature which minimizes metabolic activities and stress in fish) for long distance transportation of red-spotted grouper (Epinephelus akaara), by evaluating the behavior, survival and physiological and hematological responses to variable water temperature conditions (9, 12, 15, 18 and $21^{\circ}C$) for 48 hours. Fish exposed to $9^{\circ}C$ died at 48 hours exposure, but those exposed to 12, 15, 18 and $21^{\circ}C$ treatment groups all survived. Fish in the 15, 18 and $21^{\circ}C$ exposure groups exhibited normal swimming, while those exposed to $12^{\circ}C$ were observed to be stationary at the bottom of the tank. The plasma cortisol and glucose concentration were higher in fish exposed to $12^{\circ}C$ than at other temperature conditions. The fish in the 12 and $15^{\circ}C$ groups had significantly higher hematocrit (Ht) and hemoglobin (Hb) than those in the 18 and $21^{\circ}C$ groups (P<0.05). Levels of aspartate aminotransferase (AST), $NH_3$ and osmolality showed a pattern similar to the levels of plasma cortisol, while alanine aminotransferase (ALT) and total protein did not significantly vary among the experimental groups. These results indicate that the optimum water temperature for long distance transportation of the red-spotted grouper is $15^{\circ}C$.

• Korean Journal of Poultry Science
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• v.45 no.3
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• pp.193-200
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• 2018

The purpose of this study was to evaluate the influence and safety of spraying Farm Clean-S (FC-S) containing 70% Chamaecyparis obtusa essential oil on the elimination of red mite in laying hens. In total, 300 laying hens (ISA brown) aged 72 weeks and infected with red mite were assigned to individual cages for five treatments with five replicates for 18 days. Treatments consisted of distilled water (negative control; NC), commercial spray product (positive control; PC), FC-S 0 (original concentration), FC-S 50 (50 times diluted) and FC-S 100 (100 times diluted). The number of red mites, egg production and weight of each group were evaluated daily throughout the whole experimental period. Egg quality and blood biochemical parameters were measured at the end of the experiment. Safety tests were confirmed by feed intake, respiration, lethargy, diarrhea and mortality symptoms after the feeding trial. As the result, more than 80% of red mites were eliminated by the FC-S 0 spray treatment, and FC-S 50 also showed a higher elimination percentage than did PC (P<0.01). However, the elimination effect of the FC-S 100 spray was lower than that of the PC, but higher than that of the NC (P<0.01). These results confirmed that the optimum FC-S dilution rate ranged from 0~50 times with distilled water to eliminate the red mite effectively. The performance, egg quality, blood parameter and safety tests were not significantly different among treatments. Thus, FC-S 0 and FC-S 50 spray treatments can effectively and sustainably control red mite infestations without detrimental effects on the performance, egg quality and plasma biochemical properties of laying hens.

• Journal of fish pathology
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• v.3 no.2
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• pp.69-77
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• 1990

Tilapia, Oreochromis niloticus, weighing 100g on average was fed on the oxidized pellet diets in peroxide value (POV) 102 meq/kg, with or without the vitamin mixture of C and E for 67 days. After administration of vitamin mixture for 67 days, the fish fed them displayed better growth than the fish fed oxidized pellet only. The fish fed low level of the vitamin mixture or the oxidized pellet retained visceral ceroidosis but did not show myopathy. But the fish administered high level of the vitamin mixture lossed macrophages disposing of ceroid in the viscera. Based on the results, the administration of vitamin mixture at high level was effective as prophylaxis for ceroidosis.

• Journal of fish pathology
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• v.1 no.1
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• pp.51-57
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• 1988

Pleistophora disease is well known as microsporidiosis at eel cultural farms in Korea in recent years. Major objects of this study were to undertake the induction of Pleistophora infection experimentally and to carry out histopathological investigation from December 1984 to June 1986. Experimental infection of Pleistophora spores into young eels was carried out by oral and immersed administration. Both methods induced the same symptom successfully as that in naturally occurring diseased fish. Remarkable whitish lesions developed mainly on the body surface around the abdomen when orally administrated. On the other hand, they were scattered over the whole body when administrated through immersion. Histopathological investigation revealed that some cysts in the muscle were observed 21 days after administration. Spores were developed within the cyst. Each sporont has undergone several nuclear divisions to form a pair of multinucleate cells (Sporoblasts) enclosed within a common coat (Pansporoblast). All stages were surrounded by cyst. The cysts were destroyed and mature spores were scattered in the muscle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.295-302
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• 2018

This study was conducted to investigate effect of feeding fermented hulless barley (FHB) on growth performance and blood metabolites in growing pigs. Forty-five pigs (LYD; initial body weight, $30.33{\pm}0.05kg$) were randomly allotted into three dietary treatments that consisted of 0, 0.5 and 1.0% of the FHB in the basal diets. The pigs fed 0.5% FHB showed higher average daily gain than the 0 and 1% FHB treatments, although there was not significant among the treatments. Similarly, average daily feed intake and feed conversion ratio were not different among the treatments. Blood white blood cells, neutrophil, lymphocyte, monocyte, eosinophil and basophil were ranged to reference values, but not difference among the treatments. Serum glucose was increased in the control compared with 0.5 and 1.0% FHB. However, parameters related to protein, lipid and mineral also were not different among the treatments. These results indicate the FHB has no significant effect of growth performance and metabolizable responses in growing-finishing pigs.

• The Korean Journal of Malacology
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• v.19 no.1
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• pp.19-24
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• 2003

Artificial spawning, larval and spat developments of the bay scallop, Argopecten irradians, which was transplanted from China on 16 August 1996, were investigated monthly until August 1997 in the Deukyang Bay, Jangheung-gun, Jeollanam-do, Korea. Sufficient amount of cultured microalgae supplemented seawater were supplied as food (6 kinds of phytoplankton) for fully grown adult individuals at 17.1-23.2$^{\circ}C$ for 44 days. A total of 45,320,000 eggs were spawned by way of 2 times of artificial spawning inductions such as exposure stimulus to the air and thermal shock (with water temperature) on 29 January and 31 January in 1997. Artificially fertilized eggs were developed to D-shaped larvae (77.5 ${\times}\;63.8\;{\mu}m)$ and metamorphosed to larvae (191.8 ${\times}\;181.2\;{\mu}m)$ 181.2 m) in the attached larval stage on the collectors. A total of 110,000 spats (average 3.04 mm in shell length) were produced at 22.8-26.3$^{\circ}C$ and 31.0-34.4 psu in the indoor rearing tank from 14 February through 7 May in 1997. In case of Argopecten irradians, if the attached larvae in the attachment stage are detached from the collector, they could not live. Accordingly, it is assumed that survival (%) of the attached larvae of A. irridians showed very low because of weak power attached to the collector due to the small number of the byssuses of the attached larva, not the short attachment period by the byssus as seen in other scallops such as Argopecten balloti.