• Asian-Australasian Journal of Animal Sciences
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• 제14권10호
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• pp.1460-1464
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• 2001

This study compared the lipid metabolism of white Leghorn layers between the growing and the laying periods. The study was conducted on thirty layers in the growing period (14 weeks old) and in the initial laying period (36 weeks old; 14 weeks from the onset of laying). Results indicated that all plasma lipid traits were significantly different (p<0.05) between the two periods. The estrogen concentration in the laying period was about 3 fold that in the growing period. Triacylglycerol (TG) concentration in the laying period was about 12 fold that in the growing period. The phospholipids, cholesterol, glycerol and non esterified fatty acid (NEFA) in the laying period were also higher than those in the growing period (p<0.05). Lipogenic enzyme activities in the laying period were higher than in the growing period (p<0.05). High-density lipoprotein (HDL) was the largest lipoprotein portion in growing layers. In laying hens, the major lipoprotein portion was very low-density lipoprotein (VLDL). It was also shown that protein is the primary component of HDL and TG is the largest portion of VLDL in both periods. In laying hens, VLDL contained more TG than that in growing layers (p<0.05). The VLDL particle size in laying hens was larger than that in growing layers (p<0.05). This study indicates that the lipid metabolism traits of a layer in the laying period were different from those in the growing period. The lipogenesis related traits in the laying period were markedly greater than in the growing period.

• Asian-Australasian Journal of Animal Sciences
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• 제12권7호
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• pp.1090-1095
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• 1999

In order to minimize the occurrence of fatty liver, this study investigated how adding a high level of dietary choline or methionine affected the lipid metabolism of Tsaiya ducks. Feeding trials were conducted with sixty Tsaiya ducks during their growing period, when they were 8-12 weeks old, and during their laying period, 10-14 weeks after the onset of laying when they were 26-30 weeks old. The ducks were randomly assigned to one of three groups: a control group (basal diet), a group in which methionine was added to the basal diet, and a group in which choline was added to the basal diet. The levels of methionine and choline added were twice as high as the levels recommended by the NRC for layer-type chickens. Experimental results indicated that adding choline to the basal diet of growing ducks significantly (p<0.05) increased their body weight, while adding methionine significantly (p<0.05)reduced their body weight. Adding either choline or methionine reduced the ducks' liver fat content in both the growing and the laying periods (p<0.05). Ducks receiving added methionine or choline in their diets displayed enhanced egg production (p<0.05). Adding choline increased serum triacylglycerol (TG) in the laying period (p<0.05). Adding either choline or methionine did not significantly (p>0.05) affect the t-globulin level. Adding methionine increased the activity of liver malic dehydrogenase in both the growing and the laying periods, and increased fatty acid synthetase in the laying period (p<0.05). While adding choline markedly (p>0.05) increased VLDL and apo B in both the growing and the laying periods, it decreased HDL and apo A in the laying period (p<0.05). This study found that adding a high level of choline to the basal diets of Tsaiya ducks in both the growing and the laying periods had beneficial effects. Furthermore, adding methionine affected the lipid metabolism of Tsaiya ducks to a lesser extent than adding choline.

• Asian-Australasian Journal of Animal Sciences
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• 제12권8호
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• pp.1258-1262
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• 1999

With an attempt to elucidating the lipid metabolism of Tsaiya ducks, thirty ducks at growing (8 weeks of age) and laying periods (10 weeks after the onset of laying) were examined, respectively. The ducks were randomly allocated into ad libitum feeding and 3-day fasting groups, to investigate their in vitro hepatocytes lipogenesis capacity and adipocytes lipolysis rate. Results indicate that (1) the capacity of hepatocytes incorporation of glucose and acetate into total lipid and metabolite of $^{14}CO_2$ production during the laying period was greater than during the growing period. Approximately 50% of the glucose or acetate converted into triacylglycerol (TG) by the hepatocytes were recovered as fatty acid during the growing period, while it was 65-70% during the laying period. (2) Acetate used for lipogenesis ability was superior to glucose in both periods. (3) The adipocytes lipolysis rate was increased significantly (p<0.05) by fasting. In contrast, the capacity of incorporated glucose or acetate into total lipid, triacylglycerol, fatty acid and glycerol by hepatocytes was reduced significantly (p<0.05) by fasting.

• Asian-Australasian Journal of Animal Sciences
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• 제16권3호
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• pp.403-408
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• 2003

The study investigated the lipid metabolism of Tsaiya ducks under fasting and ad libitum feeding conditions. Sixty Tsaiya ducks in their growing period (8-12 wk-old) and sixty Tsaiya ducks in their laying period (26-30 wk-old, 10-14 weeks after the onset of laying) were randomly divided into ad libitum feeding and 3-day fasting groups. The activities of lipid metabolism related enzymes were determined. Experimental results indicated that fasting depressed the activities of lipogenesis related enzymes such as fatty acid synthetase and NADP-malic dehydrogenase in both periods (p<0.05). Fasting also increased the activities of liver fatty acid $\beta$-oxidation enzymes (p<0.05). However, the activities of lipoprotein lipase in adipose tissue, heart and ovarian follicle in both periods and the hormone-sensitive lipase of adipose tissue in the growing period were decreased by fasting (p<0.01).

• Asian-Australasian Journal of Animal Sciences
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• 제15권2호
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• pp.254-265
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• 2002

Soybean meal (SBM) is a major protein source in poultry feeds and one of the best quality ingredients because of the relatively high protein content, good amino acid profile and bioavailability. But soybean meal quality is largely dependent on the processing technology and origins. In this experiment, effects of three different soybean meals were evaluated in layer (experiment 1) and broiler (experiment 2). Soybean meal sources used in the experiments were the US-originated dehulled soybean meal (USDHSBM), India-originated non-dehulled soybean meal (India SBM) and Brazil-originated non-dehulled soybean meal (Brazil SBM). Experiment 1 was conducted during growing and laying periods and evaluated the interactive effects of soybean meal sources according to feeding periods on growth performance and egg quality. Experiment 2 was conducted during growing period (day 1-35) and finishing period (day 35-42). The growth performance was measured for the same periods and any possible interaction between soybean meal origins and crude protein levels was also studied. In experiment 1, chicks fed India SBM utilized feed more efficiently (p<0.05) than those fed Brazil SBM from day 29 to day 42. The body weights of layers during the laying period had no relation to egg production. But egg weights were significantly heavier in all the USDHSBM fed groups than other groups (p<0.001) and depended on feed protein source during growing period (p<0.001). The average egg weight of the USDHSBM fed group scored the highest value (65.4 g), followed by the Brazil SBM fed group (62.1 g) and India SBM fed group (62.1 g). There was an effect of interaction between origins of soybean meal fed group in growing and laying period on eggshell color (p<0.01). Eggshell was significantly stronger in the USDHSBM fed (for growing period) groups than other groups (p<0.05) on $31^{st}$ week. Haugh's unit (HU), albumin index and yolk index of the USDHSBM fed group in growing stage were significantly superior (p<0.001) to other groups. In experiment 2, for the 7-week, chicks on the India SBM group gained less (p<0.001) weight than other groups. While daily gain of India SBM chicks was not affected by dietary crude protein level, those of the USDHSBM and Brazil SBM chicks were linearly increased as dietary crude protein level increased from 18% to 20%. The gain per feed ratio of the USDHSBM group was the highest (0.585), followed by the Brazil SBM group (0.568) and India SBM group (0.550) (p<0.01). Therefore, in this experiment, the use of USDHSBM with excellent protein quality and amino acid digestibility could be of advantage to the economic production of layer and broiler.

• Journal of Animal Science and Technology
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• 제64권4호
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• pp.717-726
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• 2022

The study evaluated different molt-inducing methods to achieve the main goal of molting in commercial layers during molting and post-molting periods. A total of 400 60-week-old Lohmann Brown layers were randomly divided into five groups (eight replicates of 10 birds for each group). Laying hens in the fasting control group received no diet from day 1 to day 10. The second group received a molt-inducing diet recommended by the breeding company. The third group received a wheat bran-based diet. The fourth group received a commercial layer diet with 8,000 ppm zinc (as zinc oxide, ZnO). The fifth group received an induced molting diet given to the second group with 8,000 ppm zinc, respectively. Egg production in the fasting control group and groups fed a diet with ZnO were significantly lower (p < 0.001) than those in groups fed the molt-inducing and wheat bran-based diets without ZnO during molting. Egg laying in the fasting control group was rapidly reduced and stopped on the 5.9th day of molting. In both groups having molt treatment with ZnO, egg production was similarly reduced and ceased on the 6.9th day and 7.0th day of molting, respectively, none of them differed significantly from the control. Layers fed molt-inducing diet or wheat bran-based diet did not reach the cessation of laying even on the 28th d of molting period. Relative weights of the ovary and growing oocytes of layers subjected to fasting or fed diets with ZnO were significantly lower than those of other groups. During the first two weeks of post molting, layers fed molt-inducing diet with ZnO showed higher egg production than the other two groups (p < 0.01). The eggshell strength in the group fed the commercial diet with ZnO was significantly higher than those fed the molt-inducing diet or wheat bran-based diets at 6 weeks of post molting (p < 0.05). These results suggest that the non-feed withdrawal molting using ZnO is more effective in inducing molting and increasing post-molt egg production and egg quality than other methods using a molt-inducing diet alone or wheat bran-based diet without ZnO.

• The Korean Journal of Ecology
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• 제26권6호
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• pp.341-347
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• 2003

이 논문에서는 우리나라 적지적수 연구사에 관한 사료를 제시하였다. 필자는 조선시대의 임금에 대한 진상을 목적으로 한 적지적수사와 일제강점 초기의 간이적인 적지적수 연구 및 실시사례, 강점중기에 이르러서는 조선수목죽류 기후상적지도, 후기에는 속성수의 절지식재시험 및 지역별 조림수종 선발시험 등에 관한 주요 자료를 해외에서 수집 발굴하였다. 조선수목죽류 기후상적지도는 아직까지 국내에 알려지지 않은 자료로서 향후 우리나라 산지의 지원화 및 산불 피해지 복구조림, 남북통일을 대비한 북한지역 녹화사업의 기초자료로서 뿐만 아니라 고유임상 및 식생연구 등에도 유용하게 사용될 것으로 기대된다.

• 한국가금학회지
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• 제13권2호
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• pp.179-186
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• 1986

본 연구는 1985년 5월부터 1986년 9월까지 천연기념물 265호인 한국재래조골계 총 749수와 45,340개의 종란에 대하여 수정율, 부화율, 생존율, 체중 그리고 산란성등을 조사하였는 바 얻어진 결과를 요약하면 다음과 같다. 1. 수정율은 82.2$\pm$1.37%(X＋S.E.)이고, 부화율은 79.0$\pm$1.91%였다. 2. 육추율은 90.5$\pm$1.69%, 육성율은 77.9$\pm$2.28%이고 성계생존율은 80.6$\pm$3.06%로 나타났다. 3. 체중은 부화시 31.5$\pm$0.43, 18 주령시 1209.3$\pm$17.29, 24 주령시 1646.1 $\pm$25.80, 44주령시 1975.3$\pm$49.56 그리고 72 주령시는 2096.7$\pm$40.83g이었다. 4. 초산일령은 은 165.5$\pm$1.69일이었고, 란중은 초산시, 44주령시, 72주령시에 각각35.7$\pm$0.49, 48.8$\pm$0.47, 50.2$\pm$0.44g이었다. 산란수는 44주령까지는 69.5$\pm$3.10개이고, 72 주령까지는 129.3$\pm$5.56개였다. 5. 체중과 초산일령사이에는 낮은 상관과 부의 관계가 있었다. 24주, 44주, 72주령의 체중과 란중간에는 정의 상관관계였으나, 이들 체중은 44주와 72주까지의 산란수에 대하여 유의한 부의 상관관계가 있었다. 초산일령은 초산시 란중에 대하여 정의 상관이었으나, 44주와 72주까지의 산란수에 대하여는 부의 상관관계가 있었다.