• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.57-67
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• 2009

These studies were conducted to investigate the various dietary CP and ME feeding effect on productivity, blood composition and meat quality in cross bred chicks. Seven hundred twenty one day old cross bred chicks (Hanhyup Samho) were alloted to the floor pen for early starting (0~2 weeks), starting (3~5 weeks), growing (6~8 weeks), finishing period (9~10 weeks). Dietary ME and CP were 3,000, 3,100 kcal/kg, and 22% for early starting period, 19, 20, 21% for starting period, 18, 19, 20% for growing period, 17, 18, 19% for finishing period. Weight gain and feed consumption were weekly measured and feed conversion ratios were calculated. Blood and breast meat were collected at the end of experiment. Birds fed ME 3,100 kcal/kg diets improved significantly compared with others for the first two weeks (P<0.05). Feed conversion was statistically improved in CP (22)21% treatment relative to that of CP (22)20% from three to five weeks of age. No difference were found from 6 to 8 weeks of age. Weight gain and feed conversion also improved in ME 3,100 kcal/kg treatments, but feed intake decreased significantly in CP ($22{\times}21{\times}20$)19% treatment for the rest of experimental period (P<0.05). There was interaction between ME and CP for the first five weeks (P<0.05). Blood total protein showed higher in ME 3,100 kcal/kcal treatment than ME 3,000 kcal/kg (P<0.05). There were no differences in albumin, total cholesterol and glucose, but CP ($22{\times}20{\times}19$)18 treatment showed higher glucose than other treatments (P<0.05). Cooking loss, tenderness and water holding capacity were not different. However, pH was dependent on dietary ME, CP and existing the interaction between ME and CP treatments (P<0.05). As the results of this experiment, ME and CP were confirmed the 3,000 kcal/kg, 22% for the first two weeks 3,100 kcal/kg, 21% from three to five weeks of age, 3,100 kcal/kg, 18% for the growing period, 3,100 kcal/kg, 17% for the rest of period. However, further research would be required to confirm more optimum dietary nutrition for cross bred chicks.

• Korean Journal of Poultry Science
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• v.35 no.4
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• pp.399-405
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• 2009

Two experiments were conducted to establish the basic data of feeding system in cross-bred Korean native chicks. A total of seven hundred twenty chicks were replaced the 36 floor pen for the first five weeks with $3{\times}3$ factorial design in Experiment 1. Four hundred eighty of five weeks old chicks were raised from six to ten weeks of age with $3{\times}2$ factorial design in Experiment 2. Dietary ME and CP were formulated to contain 3,000, 3,050, 3,100 kcal/kg and 21, 22, 23%, respectively in Experiment 1 and 3,050, 3,100, 3,150 kcal/kg and 18, 19% in Experiment 2. Weight gain, feed intake were measured and calculated the feed conversion. Blood were collected and analyzed at the end of experiments. In Experiment 1, weight gain showed significantly higher in 3,050, 3,100 kcal/kg treatments than 3,000 kcal/kg treatment (P<0.05), but was not different in CP treatments. Feed intake was statistically high in 3,000 kcal/kg treatment compared with 3,050 and 3,100 kcal/kg ones (P<0.05), and more increased in 21% CP treatments compared to that of 22 and 23 CP treatment (P<0.05). Feed conversion of birds fed 3,050 and 3,100 kcal/kg diet showed much lower than 3,000 kcal/kg treatments (P<0.05). FCR was signicantly improved (P<0.05) in chicks fed diets containing 21 and 22% CP as compared to that fed 20% CP. Blood protein, glucose, and total cholesterol tended to increase in high energy and diet treatments. Blood HDL was increased as dietary energy increased, whereas LDL increased in low CP treatments. In Experiment 2, weight gain was not consistent between treatments, but more increased in 18% CP treatments compared to that of 19% CP treatment from six to ten weeks old in cross bred chicks (P<0.05). Feed intake was similar to the result of weight gain, but more increased in 19% CP treatment than 18% CP treatment (P<0.05). There were no statistically difference in FCR, but seemed to improve as dietary ME increased. Blood total protein and glucose increased as dietary CP was high, but triglyceride and HDL increased in high versus low ME (P<0.05). The results of these experiments suggested that optimum dietary ME and CP, were 3,050, 3,150kcal/kg and 22, 19% for the first five weeks and second one, respectively.

• Korean Journal of Poultry Science
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• v.36 no.4
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• pp.301-309
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• 2009

The present study was conducted to determine the effect of energy restricted (ER) diet on the expressions of lipogenic genes in liver and myogenic genes in muscle tissue of broiler chickens. Energy restriction was accomplished by providing chicks with 70% (ER70) or 85% (ER85) energy level of control diet intake. Energy restricted groups of chickens were restricted for 7 days, starting at 8 days of age. Ad libitum feeding was resumed after the restriction period, and continued through the end of the experiment. The body weight of chickens in the restricted groups gained less during the energy restriction period (P<0.05). The body weight of the ER groups were similar to the control group during the re-alimentation period. However, the body weight of the ER70 group did not catch up with that of the control group by 35 days of age. The energy restrictions during early life of chicks decreased the contents of triglycerides and cholesterol in blood (P<0.05), but those were not different among treatments after re-alimentation. The genes of fatty acid synthase (FAS) and transcription factors including SREBP and PPARγ were down regulated by restriction regimen only in ER70 (P<0.05). However, those genes were not completely recovered after re-alimentation in ER70 group. The RNA expression levels of Myo-D, Myf-5 and myogenin in all treatment groups were decreased by restriction regimen when compared with control group (P<0.05). Myogenin was highly expressed after re-alimentation, but the other genes were not different among groups. These results suggest that ER85 group shows the best growth performance by re-alimentation and the higher muscle differentiation by expressing myogenin.

• Korean Journal of Poultry Science
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• v.44 no.4
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• pp.267-274
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• 2017

This study was conducted to investigate the effect of feeding with dietary silicate based complex mineral (SCM) on the performance of laying hens. SCM at five levels (0%, 0.2%, 0.4%, 0.6% and 0.8%) was added to commercial diets, and fed to four hundred fifty Hy-Line Brown from fifty four to sixty five weeks of age. Egg production increased as the addition of dietary SCM to basal diets increased up to 0.6% (P<0.05). Furthermore, Feed intake increased in a manner similar to that of egg production (P<0.05). However, there was no difference in feed efficiency among the treatments. Eggshell thickness and breaking strength were significantly higher for the chickens fed with SCM than control from sixty weeks old to the end of experiment (P<0.05). Similarly, albumen height and Haugh unit were significantly higher for the chickens fed with SCM compared to those of control group (P<0.05). AST of birds fed SCM showed significantly higher than control (P<0.05). However, blood neutral fat level tended to increase in SCM treatments. Moreover, bone mineral density increased with SCM addition up to 0.4% (P<0.05). IL-2 (Interleukin-2) and IL-6 (Interleukin-6) levels appeared to be improved in the chickens fed with SCM addition diets, although not statistically different from all treatments. The results of this study indicated that the optimum SCM for improving the performance, egg quality and immunological competence of laying hens from 54 to 65 weeks of age was 0.6%.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.219-228
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• 2003

Two experiments were conducted to investigate the influence of dietary supplementation of yeast culture on the nutrient digestibility, performance and meat quality in growing-finishing pigs. Corn-soy basal diets contained 20, 18, and 16% CP and 3,265kcal/kg ME at different growth stages. One hundred and twenty pigs(8wk-old) were allocated into four supplementation levels of yest culture (0, 0.1, 0.2, 0.4%) in Expt 1. Weight gain, feed intake and feed efficiency were periodically recorded for 112 days. A metabolic feeding trial was conducted to measure the nutrient digestibility. Physical and chemical characteristics of the Longissimus Dorsi muscle(LM) from the pigs were measured at the end of experiment (Expt 2). In Expt 1, weight gain and feed efficiency were not different among the dietary treatment groups during the overall period. The digestibilities of protein and fiber were greater in 0.1% and 0.2% yeast culture-supplemented groups than in control (P<0.05). However, fat and ash digestibilities were not improved by the dietary treatment. In Expt 2, the LM protein content in 0.1% yeast culture-supplemented group, but not in 0.2% or 0.4%-supplemented group, was greater than that in the control group (P<0.05). The LM pH, purge loss, cooking loss and color were not affected by the dietary treatment. The LM shearing force was less in 0.2% yeast culture-supplemented group than in the control group (P<0.05). Other LM physicochemical properties did not differ between the dietary treatment groups. Total saturated and unsaturated fatty acids percentages and total cholesterol content of the LM did not differ across the dietary treatment groups.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.282-289
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• 2017

Animal Welfare is spreading throughout the world, but remains weak in Korean swine farms. Therefore, the aim of this study was to identify the effect of floor type and hanging type environmental enrichment on the behavior of growing pigs under the traditional feeding environment. A total of 45 crossbred pigs (Yorkshire${\times}$Landrace${\times}$Duroc; average weight, $33.35{\pm}5.5kg$) were assigned into three treatments consisting of control, hanging type(T1) and floor type(T2) with three replicates in semi-slurry pen. The hanging enrichment was suspended at shoulder height of the pigs, and the floor enrichment was fixed in the center of the pens. Growth and cortisol were estimated at the end of the experimental period. Behaviour patterns were analyzed on the first and eighth days after starting the experiment. Growth was not differed among control and treatments. However, cortisol was decreased in T2 compared to control(25.28 vs. 46.75 ng/mL; p<0.05). On the first day, movement and aggression were lower in both treatments than in control(p<0.01). On the eighth day, time and frequency of playing action were increased in T2 compared to T1(p<0.01) and both treatment groups showed more active behaviour than control(p<0.01). These results suggested that the enrichment may meet the natural action requirement of pigs. Therefore, our data can be utilized as basic information for welfare with environmental enrichments in farm animals.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.3
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• pp.151-157
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• 2015

Recent laboratory studies have documented that mixotrophic dinoflagellates Dinophysis spp. and heterotrophic dinoflagellate Oxyphysis oxytoxoides share a common prey, i.e. the mixotrophic ciliate Mesodinium rubrum. Nonetheless, very little is known about the population dynamics and species interactions among these protists in natural environments. To investigate the interactions between the dinoflagellate predators and their ciliate prey in the field, we took the samples twice a day from 26 July to 28 August, 2011 at a fixed station in Masan Bay and analyzed their abundances. During this study, salinity was highly variable, ranging from 5 to 28, due to the periodic input of rainfalls to the sampling station. Water temperature was on average $26.5^{\circ}C$ until 20 August and thereafter was about $21^{\circ}C$ by the end of the sampling period. The ciliate M. rubrum occurred persistently throughout the sampling period, ranging from 13 to $492\;cells\;mL^{-1}$. Cell densities of D. acuminata and O. oxytoxoides ranged from undetectable level to $19,833\;cells\;L^{-1}$ and from undetectable level to $100,333\;cells\;L^{-1}$, respectively. The high abundance of D. acuminata mostly followed the blooming of the ciliate M. rubrum, but it often did not peak even during heavy blooms of the prey, probably due to sensitivity to large salinity fluctuation and also presumably overlapped grazing by other mixotrophic dinoflagellates. The abundance of O. oxytoxoides was detected only when water temperature was lower than $24^{\circ}C$, indicating that water temperature is an important environmental factor to control the population dynamics of the dinoflagellate species.

• Korean journal of applied entomology
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• v.54 no.1
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• pp.7-15
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• 2015

CpBV (Cotesia plutellae bracovirus) is a polydnavirus and encodes a cystatin (CpBV-CST1) gene. Its overexpression suppresses insect immunity and alters insect developmental processes. This study aimed to construct a genetically modified (GM) tobacco to further explore the physiological function of the viral cystatin and to apply to control insect pests. To this end, the transgenic tobacco lines were screened in expression of the target gene and assessed in insecticidal activity. A recombinant vector (pBI121-CST) was prepared and used to transform a bacterium, Agrobacterium tumefasciens. The transformed bacteria were used to generate transgenic tobacco lines, which were induced to grow callus and resulted in about 92% of shoot regeneration. The regenerated plants were screened by PCR analysis to confirm the insertion of the target gene in the plant genome. In addition, the expression of the target gene was assessed in the regenerated plants by quantitative real-time PCR (qRT-PCR). The qRT-PCR analysis showed that the transgenic line plant expressed the target gene about 17 times more than the control tobacco, indicating a stable insertion and expression of the target gene in the transgenic tobacco line. The insecticidal activity was then analyzed using the screened transgenic tobacco lines against the teneral 1st instar larvae of the oriental tobacco budworm, Helicoverpa assulta. Though there was a variation in the insecticidal efficacy among transgenic lines, T9 and T12 lines exhibited more than 95% mortality at 7 days after feeding treatment. These results suggest that CpBV-CST1 is a useful genetic resource to be used to generate GM crop against insect pests.

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.273-282
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• 2009

The transmissible spongiform encephalopathies (TSEs) disease group are fatal neurodegenerative disorders affecting a wide range of hosts. The group includes kuru and Creutzfeldt-Jakob disease (CJD) in humans, scrapie in sheep and goats and Bovine spongiform encephalopathy (BSE) in cattle. The exact nature of the infectious agent involved in the transmission of these diseases remains controversial. However, a central event in their pathogenesis is the accumulation in infected tissues of an abnormal form of a host-encoded protein, the prion protein (PrP). Whereas the normal cellular protein is fully sensitive to protease ($PrP^{sen}$), the disease-associated prion protein ($PrP^d$) is only partly degraded ($PrP^{res}$), its amino-terminal end being removed. BSE was first reported in the mid-80s in the UK. Ten years later, a new form of human prion disease, variant CJD (vCJD) developed in the wake of the BSE epidemic, and there is now strong scientific evidence that vCJD was initiated by the exposure of humans to BSE-infected tissues, thus indicating a zoonotic disease. However, the ban on the feeding of animal-derived proteins to ruminants, and the apparent lack of vertical transmission of BSE, have led to a decline in the incidence of the disease within cattle herd and therefore, an assumed decreased risk for human contacting vCJD. The origin of the original case(s) of BSE still remains an enigma even though three hypotheses have been raised. Hypotheses are i) sheep- or goat-derived scrapie-infected tissues included in meat and bone meal fed to cattle, ii) a previously undetected sporadic or genetic bovine TSE contaminating cattle feed or iii) originating from a human TSE through animal feed contaminated with human remains. A host cellular membrane protein ($PrP^C$), which is abundant in central nervous system tissue, appear to be conformationally altered in the diseased host into a prion protein ($PrP^{Sc}$). This $PrP^{Sc}$ is detergent insoluble and partially protease-resistant ($PrP^{res}$). The term $PrP^{res}$ is normally used to describe the protein detected after protease treatment, in techniques such as Western immunoblotting, and enzyme-linked immunosorbant assay using fresh/frozen tissue. Immunohistochemistry may performed with formalin-fixed tissues. Also, clinical signs of the BSE are one of the major diagnostic indicators. Recently, atypical forms (known as H- and L-type) of BSE have appeared in several European countries, Japan, Canada and the United States. An unusual case was also reported in a miniature zebu. The atypical BSE fall into two groups based on the relative molecular mass (Mm) of the unglycosylated $PrP^{res}$ band relative to that of classical BSE, one of the higher Mm (H-type) and the other lower (L-type). Both types have been detected worldwide as rare cases in older animals, at a low prevalence consistent with the possibility of sporadic forms of prion diseases in cattle. This raises the unwelcome possibility that vCJD could increase in the human population. Now, active surveillance program against BSE is going on in Korea. In regional veterinary service lab, ELISA is applied to screen the BSE in slaughter and confirmatory tests by Western immunoblotting and immunohistochemisty are carried out if there are positive or suspect in the screening test. Also, the ruminant feed ban is rigorously enforced. Removal of specified risk materials such as brain and spinal cord from cattle is mandatory process at slaughter to prevent the infected material from entering the human food chain.

• Journal of Aquaculture
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• v.7 no.1
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• pp.63-76
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• 1994

The effects of different dietary lipids on growth, body chemical composition, and nutrient partition of the Korean rockfish (43 g of initial mean weight) were studied. Fish were fed three experimental diets containing 1) $4.5\%$ squid liver oil, 2) $1\%$ squid liver oil and $3.5\%$ beef tallow, and 3) $1\%$ squid liver oil and $3.5\%$ soybean oil. Growth and feed efficiency were detarmined during a 19-week feeding period at water temperature of $15.5^{\circ}C$, and at the end of which body chemical compositions were analyzed. Remained fish were fasted for 45 days, and four fish were taken at 6, 12 and 24 hours, and 3, 15 and 45 days after the fasting to determine tissue compositions and hematological changes. Growth, feed efficiency, protein and lipid retention efficiency, hepatosomatic index(HSI), viscerosomatic index (VSI), and chemical composition of whole body and dorsal muscle were not affected by the different dietary lipids. Liver moisture content of fish fed squid liver oil diet was higher than that of fish fed beef tallow or soybean oil diet. Liver lipid content of fish fed beef tallow diet was higher than that of fish fed the other diets. Fatty acid composition of dorsal muscle and liver were affected by the different dietary lipids ; high levels of 20 : 5n-3 and 22 : 6n-3 from fish fed the diet containing squid liver oil, 18 : 1 from fish fed the diet containing beef tallow, and high 18 : 2n-6 and 18 : 3n-3 from fish fed the diet containing soybean oil were observed. Both HSI and VSI of fish fed three diets decreased with time after the begining of starvation. Liver glycogen did not change during the first 15 days of starvation and decreased thereafter, and that was not affected by the different dietary lipids. Lipid and protein contents in the dorsal muscle of fish decreased up to 15 days of starvation and remained unchanged thereafter, these were not different from each other. Glucose, free fatty acid, triglyceride and phospholipid concentrations in Fish serum were varied for the first 15 days of starvation, after that the concentrations of fish serum remained relatively stable in all the treatment groups with prolonged starvation. The results indicate that Korean rockfish can utilize fish oil, animal fat or vegetable oil equally as energy source when n-3HUF A is adquate.