• Journal of Aquaculture
• /
• v.20 no.1
• /
• pp.14-18
• /
• 2007

Seed production of the cherry salmon, Oncorhynchus masou (Brevoort) were studied in terms of egg development, hatching rate, juvenile growth, smolt duration, smolt rate, and adult growth rates. Fork length and body weight of $0^+$ juvenile were $9.32{\pm}1.19\;cm$ and $9.36{\pm}3.50\;g$ for females and $9.07{\pm}1.02\;cm$ and $8.57{\pm}3.04\;g$ for males, respectively. Body weights of $1^+$ smolt were $84.09{\pm}18.1\;g$ and $86.33{\pm}41.2\;g$ for females and males, while body weights of $1^+$ parr were $101.88{\pm}60.9\;g$ and $98.38{\pm}39.6\;g$ for females and males, respectively. Monitoring of gonadosomatic index (GSI) confirmed that maturations of both sexes were not synchronous; males achieved highest GSI in September, while females achieved it in October.

• Journal of Nutrition and Health
• /
• v.50 no.3
• /
• pp.225-235
• /
• 2017

Purpose: This study aimed to investigate the potential of freeze-dried persimmon powder (Diospyros kaki Thumb.) to protect against dyslipidemia induced by a high-fat/cholesterol diet (HFD) in a rat model. Methods: Fifty Wistar rats were randomly divided into five groups: normal control (NC), high-fat/cholesterol control (HC), tannin in HFD (HT, 1% of diet), immature persimmon in HFD (HI, 7% of diet), and mature persimmon in HFD (HM, 7% of diet). Tannin was used as a positive control. Biochemical, molecular, and histopathological changes were observed in the blood and liver. Results: We confirmed that a high fat/cholesterol diet successfully induced dyslipidemia, which was characterized by significantly altered lipid profiles in the plasma and liver. However, oxidized low-density lipoprotein levels, histopathological damage in the liver, and hepatic triglyceride levels were significantly reduced in all HT, HI, and HM groups compared to those in the HF group. In contrast, plasma apolipoprotein B level was significantly reduced only in the HT and HM groups, whereas reduction of the LDL-C level was detected only in the HI group. Although HF-induced sterol regulatory element-binding protein (SREBP) gene expression was significantly reduced in all treated groups, downstream gene expression levels varied among the different groups; significant reduction of fatty acid synthase (FAS) and 3-hydroxy-3-methylglutaryl-CoA (HMGCR) gene expression was detected only in the HI group, whereas cholesterol $7{\alpha}$-hydroxylase (CYP7A1) gene expression was significantly elevated only in the HM group. Conclusion: Taken together, the data suggest that protection of LDL oxidation and hepatic lipogenesis might be, at least partly, attributed to tannin in persimmons. However, the identified mechanisms varied up to the maturation stage of persimmon. In the case of immature persimmon, modulation of FAS and HMGCR gene expression was prominent, whereas in the case of mature persimmon, modulation of CYP7A1 gene expression was prominent.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.5
• /
• pp.526-535
• /
• 2001

The gametogenesis, reproductive cycle, frequency distribution of egg diameter and fecundity of spotted sea bass Lateolabrax maculatus were investigated by histological observation. The samples were collected at Goheung, Jeonam from December 1996 to November 1997. Gonadosomatic index (CSI) was appeared less than 1.0 in female and male from December to July and began to increase from August and reached the maximum values of female 7.50 and male 2.98 in October. Hepatosomatic index (HSI) was appeared annual maximum value of female 1.97 and male 1.64 in March and then decreased from April. The annual reproductive cycle of this species can be divided into four successive stages: growing stage (July to August), maturation stage (September to October), ripe and spawning stage (October to November) and degeneration and resting stage (November to July). According to the frequency distribution of egg diameter, the development mode of egg was not seperated, formed one mode for the maturation and spawning season, The individual absolute fecundity ranges from $1,726,242\~17,822,576$ eggs, and individual relative fecundity ranges from $29,458\~214,730$ eggs in total length (cm) and $938\~3,363$ eggs in body weight (g). Female and male of L. maculatus were matured when total length were over 50.1 and 45.1 cm, respectively.

• Journal of Life Science
• /
• v.23 no.3
• /
• pp.333-340
• /
• 2013

This study was performed to determine whether stem bark extract containing saponin of Albizzia julibrissin in the diet influences gonadal maturation and spawning in medaka (Oryzias latipes). The crude extraction containing saponin (HaBC) was partially purified from n-BuOH extraction of A. julibrissin stem bark by Diaion HP-20, Silica gel and Sephadex LH-20 chromatographies. We fed diets supplemented with HaBC to medaka. We then studied the effects of the HaBC supplement on the suppression of gonadal maturation and spawning in female medaka that were reared in aquaria with recirculation systems. In the experiment with immature female medaka, the periods of initiation of gonadal maturation and spawning were delayed in the fish that were fed diets supplemented with at least HaBC 20 mg/g-feed. In the experiment with mature female medaka, the fish that were fed diets supplemented with at least HaBC 20 mg/g-feed had lower GSIs than the control diet group did. The results showed that the growth of the immature medaka was not correlated with the amount of supplementation of HaBC in the diet. However, the condition factors (CF) in the medaka that were fed diets supplemented with at least HaBC 20 mg/g-feed were higher than in the medaka fed on the control diet. We concluded that extracts containing saponin from the stem bark of A. julibrissin have the potential to inhibit gonadal maturation in female medaka, but they did not act as growth stimulation. Further studies are required to determine the mechanism of the action.

• Journal of Yeungnam Medical Science
• /
• v.18 no.1
• /
• pp.94-100
• /
• 2001

Background: It is doubtful that aging causes deteriorated glucose metabolism and insulin resistance of skeletal muscle. Some researchers had different results about it. So we have studied the mechanism responsible for the abnormal glucose tolerance associated with aging in rapidly growing and matured rats. Materials and Methods: Animals were used S.D. rats. Growing rats were 7 weeks old (BW: 160-190 gm) and matured rats were 28 weeks old (BW: 420-525 gm). Results: Fasting blood glucose and plasma insulin levels were significantly elevated in matured rat compared with growing rats. And during oral glucose tolerance test the glucose level was also significantly elevated in matured rats. These results confirmed an insulin resistant state of aging. Insulin levels at 30 minutes of oral glucose tolerance test was significantly elevated in growing rat. But at 120 minutes it was maintained at higher level in matured rats than in growing rats. It suggested the possibility of increased insulin secretion by initial stimulation of beta-cells in growing rats, and increased secretion and decreased catabolic rate of insulin in matured rats. Glucose uptake rate of soleus muscle in matured rats was lower than that of growing rats, but the difference was not statistically significant. The dose(insulin)-responsive(glucose uptake) curve of soleus muscle was only slightly deviated to the right side. Conclusion: Glucose metabolism of rat skeletal muscle was worsened by aging. The data of glucose uptake experiments suggested the possibility of insulin resistance of skeletal muscle in matured rats. but the mechanism of insulin resistance of skeletal muscle need further studies.

• Korean Journal of Soil Science and Fertilizer
• /
• v.23 no.3
• /
• pp.180-187
• /
• 1990

This experiment was conducted to find a methode reducing peant empty pods when it was cultivated on a newly reclaimed upland soil in Kimjae, Jeonbuk, Korea. Liming materials, slaked lime and dolomite were applied to the soil at two levels : lime requirement amount neutralizing the soil and one of 1.5 times. The results are summarized as the followings. 1. There was a yield increase of 27% from the field applied 1.5 times amount of dolomite Compared to that of slaked lime. The number of empty pods per plant was at the lowest level with the treatment of higher amount of dolomite. 2. At the maturing stage of the plant there was a positive significant correlation observed between the content of MgO and other parameters such as no, of branchs per plant dry weight per plant, no, of pods per plant and 100 seed-weight. But the correlation between MgO content and the no of empty pods was negatively significant at 5% level. 3. The content of CaO and MgO was significantly correlated to hull and pod volumes, pod surface area, hull thickness and hull weight. 4. Correlation coefficients between yield and the contents of Ca and Mg in soil at mauring stage were $0.572^{**}$ and $0.556^{**}$ respectively.

• Journal of agriculture & life science
• /
• v.50 no.4
• /
• pp.113-125
• /
• 2016

This study was conducted to investigate the effect of low feeding level of concentrate after sexual maturity(14 month old) on the growing and breeding performances in Hanwoo cows. Eighteen cows(average body wt. 251kg) were alloted to two groups by completely randomized design, and fed a commercial formula feed by 0.8%(T1) and 1.2%(T2) of body weight for 30 months of total experimental period(feeding trial of 20 months, breeding trial of 10 months). When the results of this experiment compared to the Korean feeding standard for Hanwoo(2012), the reason of low growing performance in T1 was induced from low protein intake rather than energy. The change of body size by feeding levels was significantly appeared at chest width and body length, particularly chest width of cows in T1 was rather reduced by 3.7% in the final than the initial measurement. Ovarian size of T1 was only 63% of T2, and pregnancy rate(33.3% : 77.8%) and birth wight of calf(22.5kg : 29.5kg) were also seriously repressed by low intake of dietary protein after sexual maturity in Hanwoo cow. It was appeared that the growing and breeding performances of Hanwoo cows were more affected by the level of dietary protein rather than energy in the feeding after sexual maturity.

• Journal of Animal Science and Technology
• /
• v.45 no.5
• /
• pp.689-694
• /
• 2003

Weight records of Hanwoo cows from birth to 36 months of age collected in Daekwanryeong branch, National Livestock Research Institute(NLRI) were fitted to Gompertz, von Bertalanffy and Logistic functions. For the growth curve parameters fitted on individual records using Gompertz model, the mean estimates of mature weight(A), growth ratio(b) and growth rate(k) were 383.42 ${\pm}$ 97.29kg, 2.374 ${\pm}$ 0.340 and 0.0037 ${\pm}$ 0.0012, respectively, and mean estimates of body weight, age and daily gain rate at inflection were 141.05 ${\pm}$ 35.79kg, 255.63 ${\pm}$ 109.09 day and 0.500 ${\pm}$ 0.123kg, respectively. For von BertalanfTy model, the mean estimates of A, b and k were 410.47 ${\pm}$ 117.98kg, 0.575${\pm}$0.057 and 0.003 ${\pm}$ 0.001, and mean estimates of body weight, age and daily gain at inflection were 121.62 ${\pm}$ 34.94kg, 211.02 ${\pm}$ 105.53 and 0.504 ${\pm}$ O.l24kg. For Logistic model, the mean estimates of A, b and k were 347.64 ${\pm}$ 97.29kg, 6.73 ${\pm}$ 0.34 and 0.006 ${\pm}$ 0.0018, and mean estimates of body weight, age and daily gain at inflection were 173.82 ${\pm}$ 37.25kg, 324.47 ${\pm}$ 126.85 and 0.508 ${\pm}$ 0.131kg. Coefficients of variation for the A, b and k parameter estimates were 25.3%, 14.3% and 32.4%, respectively, for Gompertz model, 28.70/0, 9.9% and 33.3% for von Bertalanffy model, and 27.9°/0, 5.0% and 30.0% for Logistic model.

• Current Research on Agriculture and Life Sciences
• /
• v.8
• /
• pp.45-50
• /
• 1990

This study was carried out ot investigate the effects of fetal calf serum (FCS) and gonadotropins supplemented to the medium on maturation and fertilization in vitro of porcine follcular oocytes. Ovaries were obtained from gilts at local slaughter-house. Oocyte-cumulus complexes were recovered by puncturing the ovarian follicles(3~5 mm in diameter). The complexes from individual ovaries were pooled in a $0.4m{\ell}$ droplet of medium covered with paraffin oil, then washed twice in fresh droplet and cultured for 36hrs in culture media according to experimental conditions. Boar epididymal spermatozoa were capacitated by preincubation for 4hrs in m-KRB medium and the preincubated spermatozoa were insemenated in the fertilization medium containing the cultured oocytes. The results obtained in this study are summarized as follows: 1. The maturation rates of oocytes cultured in m-KRB and m-KRB supplemented to 10% FCS were 82 and 37%, respectively. When PMSG, hCG. and PMSGt hcG($10Iu/m{\ell}$) were added to the media supplemented to 10% FCS, the maturation rates were 66, 58 and 68%, respectively. 2. Expansion of cumulus cells was not occured in m-KRB and m-KRB supplemented to 10% FCS. However, when PMSG, hCG and PMSG+hCG($10Iu/m{\ell}$) were added to m-KRB supplemented to 10% FCS, the expansion rates of cumulus cell layers were 92, 13 and 91%, respectively. 3. When oocytes were mltured in m-KRB, the rates of penetration and formation of male pronucle: were 93 and 7%, respectively. By adding FCS and gonadotropin to m-KRB, the penetration and formation of male pronuclei were 100 80%, respectively.

• Korean Journal of Environment and Ecology
• /
• v.37 no.1
• /
• pp.86-93
• /
• 2023

This study investigated the ecological characteristics of Odontobutis interrupta at the Geumdang Stream from January to December 2021. The riverbed structure of the species habitat was rich in sand and mud. The water was deep, ranging from 21 to 124 cm, with an average of 48 cm. The stream velocity was slow at 0.24 (0.08-0.36) m/sec. The ratio of females to males was 1:0.98, and the total length of collected individuals ranged from 23 mm to 162 mm. The age according to the total length-frequency distribution as of May indicated that the group with a total length of 23-59 mm was one year old, the group with 60-99 mm was two years old, the group with 100-139 mm was three years old, and the group with 140-162 mm was four years old. As a secondary gender characteristic, the females genital papilla had a cylindrical shape, a hollow inside of the tip, and a longer diameter than males. The males had a cone shape with a pointed end. Sexually mature males had the nuptial color, with a black abdomen and whole body. Some females with a length ranging from 60 to 69 mm and all females 70 mm longer were sexually mature. Some males with a length ranging from 70 to 79 mm and all males 80 mm longer were sexually mature. The spawning season was from May to July, and the water temperature was between 19.6℃ to 29℃ during that period. The prosperous spawning season was June (26℃). The average number of eggs in the ovaries was 2,473 (883-4,955) per matured female, and the matured eggs were yellowish and spherical with a mean diameter of 1.42 (1.20-0.54) mm. The correlation between total length and weight was BW=0.0000006TL^3.21 with the constant a as 0.0000006 and parameter b as 3.21. The condition factor (K) was 1.67 (1.18-2.43) on average, and the slope was 0.116.