• Applied Microscopy
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• 제28권3호
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• pp.283-297
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• 1998

Hemopoiesis and morphogenesis of the human fetal liver through from 10 to 32 weeks of gestation were investigated by light and electron microscopy. The results obtained were as follows. Hemopoiesis of fetal liver tissue was found from 10 to 32 weeks of gestation, but the hemopoiesis was decreased at 32 weeks of gestation. At the 32 weeks of gestation, matured erythrocytes were observed in the sinusoid, and formation of liver cell cord and portal triad were established. Differentiation of hepatic cell was characterized by the increase of amount of cell organelles within cytoplasm, decrease of hemopoietic cell, morphological change of nuclear envelope from folding form to round form during the developmental period. These results suggest that human fetal liver plays a hematopoietic function until bone marrow and spleen play their function, but morphology of liver at 32 weeks of gestation was differed with structure observed in liver of adult.

• 농업과학연구
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• 제51권1호
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• pp.41-51
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• 2024

This study explored the effect of increased feed intake during the late gestation on the reproductive performance of sows, and fecal score in sows and piglets. A total of 21 crossbred [Landrace × Yorkshire] multiparous sows were randomly distributed into three treatments with seven replicates per treatment. Treatments: CON, 2.4 kg/day; TRT1, 3.2 kg/day; TRT2 , 3.6 kg/day. Body weight and body condition score of sow in different stages were not altered (p > 0.05) due to extra feed in late gestation. A linearly higher (p < 0.05) difference in backfat thickness during farrowing was found in this study. Average daily feed intake was increased (p < 0.05) linearly with extra feed in this experiment. The weaning body weight of piglets was increased (p < 0.05) with extra feed in the sow. The fecal score of sows and their piglets was similar (p > 0.05) in different levels of feed intake. In conclusion, extra feed to gestation sow showed a beneficial effect on improving the weaning piglet's body weight. Although there is a small improvement in the body weight of weaning pigs of sow fed 3.6 kg feed/day in the late gestation period, it is unlikely to be profitable enough to justify the additional waste of feed.

• Journal of Animal Science and Technology
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• 제52권1호
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• pp.57-64
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• 2010

This study was conducted to compare the aspects of behavior between miniature pigs and conventional sows during gestation and lactation periods. Miniature pigs and conventional sows at 3 parity were used in this experiment with 4 pigs per treatment. The behavioral patterns and stereotyped behaviors were observed on day 60 and 90 of gestation, at farrowing, and on day 10 of lactation before and after the feeding. On 60 and 90 days of pregnancy, both treatments showed the tendency of frequent lateral lying rather than other postures. On ventral lying, eating and drinking, miniature pigs spent more time than conventional pigs at day 90 of gestation (P<0.01, P=0.0539, P<0.05, respectively). The occurrence of stereotyped behaviors included bar biting and bar mouth chewing. At 90 day of pregnancy was observed, conventional pigs was higher than miniature pigs (P<0.05). At farrowing, miniature pigs spent more time on ventral lying, standing and walking than conventional sows (P<0.05), however, there were more frequency of drinking and eating. And on day 10 of lactation, there was no significant difference in stereotyped behaviors between miniature pigs and conventional sows. In conclusion, miniature pigs were generally more sensitive than conventional sows although sows were reared in stall during gestation and lactation period and the behavioral pattern during lactating period showed the similarity between miniature pigs and conventional sows for protection of nursing pigs. In consideration of the general reproductive performance of conventional sows, the high sensitivity and stress of miniature pigs did not affect the reproductive performance of miniature pigs.

• 한국가축번식학회지
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• 제16권2호
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• pp.141-147
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• 1992

The present study was conducted to find out the changes of progesterone and 20$\alpha$-dihydroprogesterone(20$\alpha$-OHP) levels during the gestation period in Korean native goats. 4 pregnant goats were offered for this experiment. Blood samples were taken from jugular vein on Day 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140 and 145 of the pregnant goats. The serum levels of progesterone and 20$\alpha$-OHP were measured by radioimmunoassay. The progesterone level in goat serum during the gestaton was low as 2.94$\pm$0.21 at 5 days, and then increased to 4.51$\pm$0.25ng/ml at 10 days of gestation and increased greatly from Days 60 and reached a peak level of 7.21$\pm$0.58ng/ml at 100 days of gestation, and thereafter decreased to 6.01$\pm$0.57, 5.26$\pm$0.64ng/ml on Days 130, 140 of gestation, and decreased to 4.05$\pm$0.52ng/ml on Days 145 of pregnancy. The serum level of 20$\alpha$-OHP during the gestation was low as 0.3~0.4ng/ml in the early stage of pregnancy, and increased gradually and increased to 0.85$\pm$0.06ng/ml, 0.97$\pm$0.08ng/ml on Days 90 or 100, and then increased to 1.18$\pm$0.18, 1.25$\pm$0.21ng/ml on Days 140 or 145 of gestation. While the serum levels of progesterone during the luteal regression decreased, the 20$\alpha$-OHP increased continuously. From the above results, it was concluded that the enzyme 20$\alpha$-hydroxysteroid dehydrogenase (20$\alpha$-HSD) catalyzing theconversion of progesterone to a biologically inactive steroid, 20$\alpha$-OHP was active properly in the luteal cells what the levels of progesterone decreased and the levels of 20$\alpha$-OHP increased during the late pregnancy in Korean native goats.

• Asian-Australasian Journal of Animal Sciences
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• 제15권8호
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• pp.1098-1102
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• 2002

A set of 313,169 reproduction records of Japanese Black cows calving between 1987 and 1996 were collected in nation widely Japan to investigate the current level of reproductive performances and the factors influencing the performances such as calving interval, first calving age, services per conception, calving difficulty, non-gestation period and gestation length. All the records of reproductive performances are outcome of artificial insemination. The means of first calving age, calving interval, non-gestation period and gestation length were 25.0 months, 389.9, 101.9 and 287.5 days, respectively. Services per conception were 1.41 and degree of calving difficulty was 1.07, which suggests most of the calving, did not need assistance. There were chronological tendencies that first calving age became younger while calving interval became longer. Differences in reproductive performance were found for seasons and calving numbers. Calving interval became shorter towards the fourth calving but became longer afterwards. The cows calving in May had the shortest calving interval followed by those in April and June and first calving age had a similar tendency. The cows with the standard body condition score showed more favourable reproductive performances compare with those with rather fatty or thin body condition scores.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.73-83
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• 2005

Higher methylmercury (MeHg) accumulation and susceptibility to toxicity in the fetus than in the mother at parturition is well known. However, the difference in MeHg exposure to fetus and offspring throughout gestation and suckling is not well established. In the human, the effects of MeHg exposure on pregnant and breast-feeding women remain an important issue for elucidation, especially those of continuous uptake in high-fish-consumption populations. The purpose of this paper was to evaluate the difference in MeHg exposure to fetus and offspring throughout gestation and lactation using our recent animal and human studies data. In the animal study, adult female rats were given a diet containing 5 ${\mu}$g/g Hg (as MeHg) for 8 weeks. Then they were mated and subsequently given the same diet throughout gestation and suckling. On embryonic days 18, 20, 22 and at parturition, the concentrations of Hg in the brains of fetus were approximately 1.5-2.0 times higher than those in the mothers. However, during the suckling period Hg concentrations in the brain rapidly declined to about 1/10 of that during late pregnancy. Hg concentrations in blood also decreased rapidly after birth. In human study, Hg concentrations in red blood cells (RBCs-Hg) in 16 pairs of maternal and umbilical cord blood samples were compared at birth and 3 months of age after parturition. RBCs-Hg concentration in the umbilical cords was about 1.6 times higher than those in the mothers at parturition. However, all the infants showed declines in Hg concentrations throughout the breast-feeding period. The Hg concentration in RBCs-Hg at 3 months of age was about half that at birth. Both the animal and human studies indicated that MeHg exposure to the fetus might be especially high but it dramatically decreases during the suckling period. Therefore, close attention should be paid to the gestation rather than the breast-feeding period to avoid the risk of MeHg to human infants.

• 대한수의학회지
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• 제12권1호
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• pp.7-14
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• 1972

Hemogram and serum composition of pregnant rabbits were studied and the results obtained were as follows: 1. Erythrocyte, hemoglobin concentration and hemotocrit value of pregnant rabbits decreased at the late stage of gestation, and 1 week after delivery the values were recovered to the normal levels. Number of erythrocyte and hematocrit value were not found to be significant, but hemoglobin concentration showed significant differences at the third and fourth week of pregnancy. 2. Total leucocytes of pregnant rabbits increased continuously as gestation progresses and 1 week postpartum the values were returned to normal. Highly significant changes were observed in the third and the fourth week of pregnancy. Neutrophil was revealed highly significant rise at the third and the fourth week of gestation and 1 week postpartum, but lympocyte was decreased highly significantlly. 3. Serum calcium of pregnant rabbits revealed the tendency of decrease as gestation progresses and 1 week after delivery the value was returned to normal, and highly significant decrease was abserved at the fourth week. Serum inorganic phosphorus of pregnant rabbits showed highly significant decrease at the fourth week of gestation, but no differences were observed at the other period of gestation and 1 week postpartum. 4. Serum protein of pregnants rabbits showed the tendency of decrease continuously pregnancy progresses, and 1 week after delivery showed the normal values. Highly significant decrease was found at the fourth week of gestation. the levels of serum lipids in pregnant rabbits was unchanged untill the third week of pregnancy, but at the fourth week and 1 week postpartum, the rise was highly significant. The level of total serum cholesterol in pregnants rabbis was shown the tendency of decrease untill the end of the second week of gestation and significantly dropped at the third week, thereafter, the value was rose significantly at the fourth week of gestation and 1 week postpartum.

• 대한수의학회지
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• 제35권1호
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• pp.11-17
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• 1995

The development of colon in fetuses between 60, 90, 120 days of gestation and neonates of Korean native goats was investigated by light scanning electron microscopy. The results were summarized as follows : 1. The colonic wall appeared to be differentiated into the epithelium, lamina propria, submucosa, tunica muscularis and serosa in 60-day-old fetus. 2. The epithelium of the colonic villi was stratified in some areas and simple columnar in others at 60- and 90day-old fetus but was only observed simple columnar epithelium at 120-day-old fetus. 3. The goblet cells and the intestinal glands appeared in the colonic mucosa at 90 days of gestation and continued gradually to increase in number during gestation. 4. The well-developed villi of the colon appeared in columnar shape at 60 days of gestation and increased in length and width until 90 days of gestation but the villi appeared to be shorter and degenerated after 120 days of gestation. At birth only the rudiment trace of the villi remained. 5. The tunical muscularis of the colon was continuously developed during gestation period. The inner circular and outer longitudinal muscle layers were distinguishly observed in the colon of 90-day-old fetuses. 6. Scanning electron microscopically, the colonic villi developed in columnar shape or finger-like of fetuses at 60 days of gestation. The of the colonic villi became degenerated after 120 days of gestation. At birth only the rudiment trace of villi remained.

• 한국수산과학회지
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• 제29권2호
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• pp.157-164
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• 1996

태생 경골어류 망상어, Ditrema temmincki의 임신기 동안 체내자어는 건중량과 체액삼투압의 증가를 나타냈으며, 모체는 난소강액의 증가와 함께 난소 내부조직상의 현저한 변화를 나타냈다. 체내자어는 난황흡수 완료시기인 전장 6.0 mm부터 전장 60.0 mm 사이에 373.76mg의 건중량 증가를 나타냈으며, 체액삼투압은 출산직전인 전장 64.0mm에는 796.8mOsmo1/kg으로 나타났다. 모체의 난소외막은 수정 이후 뚜렷히 비후되기 시작하여 임신중기인 3월에 가장 비후되고, 난소습곡은 임신후기인 4월말에 가장 팽창되며, 혈관의 팽창 및 혈구의 증가는 출산직전에 최고에 달한다. 이와같은 변화양상은 임신기 동안 체내자어와 모체의 영양${\cdot}$환경적 적응현상을 의미하는 것이라 하겠다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권10호
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• pp.1512-1518
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• 2015

This experiment was conducted to assess the welfare and productivity of gestating gilts in groups with the electronic sow feeding (ESF) system compared to conventional stalls. A total of 83 gilts ($Yorkshire{\times}Landrace$) were housed into individual stalls to be artificially inseminated. Gilts confirmed pregnant were introduced to their treatment, conventional stalls (ST) or groups with the ESF system. All gilts were taken to the farrowing crates one week prior to their expected farrowing date. In the gestation period, there were no significant differences between gilts allocated to ST and ESF on growth performance. However, backfat thickness gain (p = 0.08) and body condition score (BCS) at 110 days of gestation (p = 0.10) tended to be higher in ESF gilts than ST. Likewise, gilts housed in group showed significantly higher estimated body muscle contents at 110 days of gestation (p = 0.02) and body muscle change during gestation (p = 0.01). There was a trend for a shorter parturition time in ESF gilts (p = 0.07). In the lactation period, group housed gilts showed a tendency to increased BCS changes (p = 0.06). Reproductive performance did not differ with the exception of piglet mortality (ST = 0.2 no. of piglets vs ESF = 0.4 no. of piglets; p = 0.01). In blood profiles, ST gilts showed a higher cortisol level at 110 days of gestation (p = 0.01). Weaning to estrus interval was shorter in gilts housed in ESF than ST (p = 0.01). In locomotory behaviors, ESF gilts recorded a tendency to elevate locomotion score at 36, 70, and 110 days of gestation (p = 0.07, p = 0.06, and p = 0.06, respectively). Similarly, ESF gilts showed significantly higher incidence of scratches at 36, 70, and 110 days of gestation (p = 0.01). Moreover, farrowing rates were higher in stall treatment (97.6%) compare to group housing treatment (95.2%). In conclusion, while group housed gilts with ESF system positively affected welfare status in combination with less physiologically stressful environments and activity, it negatively effects piglet mortality, farrowing rates and injuries of gilts.