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        검색결과 5

        1.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluated genetic parameters of direct and maternal effects for calving ease in Hanwoo. A total of 2,102 records for calving ease were collected from 2018 to 2020 from the Hanwoo Genetic Improvement Center in Korea. The calving ease score was rated from 1 to 4 (1=unassisted delivery, 2=assisted easy calving, 3=assisted difficult calving, 4=mechanical or caesarean section) as categorical data, and the data were converted using a truncated normal distribution for linear model analysis. To evaluate the genetic parameters, the birth year-season of calving, the sex of the calf, parity, and the age of the dam at calving were considered as fixed effects, and genetic and maternal effects were considered random effects. The genetic parameters were evaluated using the program BLUPF90. The calving ease scores for male calves, first parity cows, and currently calving cows were much higher than for females, later parities, and past calving cows. The direct genetic variance (0.0164) was higher than the maternal genetic variance (0.0018), and the estimated heritabilities of the direct and maternal effects were 0.055 and 0.006, respectively. The parameters determined here should help with the genetic evaluation of calving ease in Hanwoo.
        4,000원
        2.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to find out that how much does it effects as it considered not only animal additive genetic effect but also maternal genetic effect for improving litter traits of pigs. The data of 10,836 records on 2,636 sows in Landrace and 14,463 records on sows in Yorkshire were analyzed which had been measured from 1998 to July 2017 in a nucleus herd of pig population. The traits used on this analysis were total number of born with (TNB2) and without mummy (TNB1) and number of born alive (NBA). Two different multivariate animal mixed models were considered and compared of variance components estimated from these models. The one (Model 1) was set up with assumed to parity, return events and batch effects as fixed and service sire, permanent environment and animal additive genetic effects as random. The other (Model 2) was same with Model 1 except considering maternal additive genetic effects as random. (Co)variance for random effects and genetic parameters were estimated using restricted maximum likelihood method and breeding values as best linear unbiased prediction were estimated using preconditioned conjugate gradient algorithm on each model and breed. From these models, heritability estimates for NBA were about 0.10 and 0.11 on both models in Landrace and Yorkshire, respectively. Forthermore, it was estimated that there were little variations in the maternal genetic effects with roughly 1~2% of total variation. Result from comparing estimated breeding values for each trait between each model, ranking of genetic capability through total breeding values on model 1 and on model 2 showed highly correlated with more than 0.92. Consequently, for improving litter traits, selection based on breeding values by direct genetic effects without considering maternal genetic effects were reccommendable.
        4,000원
        4.
        2006.12 구독 인증기관 무료, 개인회원 유료
        Di-n-butyl phthalate (DBP), diisononyl phthalate (DINP) and di-(2-ethylhexyl) adipate (DEHA) are ubiquitously distributed chemicals that are widely used as plasticizers and also found at low levels in foods. The aims of this study were to determine whether perinatal exposure to DBP, DINP and DEHA could alter normal patterns of neonatal development. Dams were provided with pulverized soy-free diet containing 20, 200, 2,000 and 10,000 ppm of DBP, 40, 400, 4,000 and 20,000 ppm of DINP, or 480, 2,400 and 12,000 ppm of DEHA from gestational day 15 to postnatal day 21. Exposure to the high doses of DBP, DINP and DEHA during gestational period significantly decreased food consumption and body weight gain of dams. These chemicals reduced neonatal body weight as well as that of the after maturation. Also, exposure to DINP of all the doses used and the higher doses (2,400 and 12,000 ppm) of DEHA decreased AGD at PND 1 in male neonates, though that to DBP did not affect AGD in males. In female neonates, an increase in AGD was observed in DBP- and DINP-exposed animals at the highest doses. Moreover, these chemicals affected survival rate of pups at PND 5, and delayed onset of eye opening in all chemical-exposed groups at PND 17. These results suggest that perinatal exposure to these chemicals may affect the normal development and / or growth of offspring.
        4,200원
        5.
        2001.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Maternal stress was very common symptom that every pregnant women could have experienced during pregnant period. We found that the causative factors of stress for subjects were physical change(50.8%), family relationship(13.6%), change of body image(7.4%), concern baby(6.8%), economic difficulties(6.4%), depress(4.3%), morning sickness(3%), and miscellaneous(3.5%). According to our study, maternal stress during the first trimester negatively correlated with food and nutrients intake of pregnant women and gave low weight gain during pregnancy and low birth weight of infants. It also significantly correlated with monthly income(p〈0.001) and monthly food cost(p〈0.001) during pregnant period. Mean intake of Calcium and Iron were 47~60% of RDA and 35~48 of RDA, respectively. With the Iron supplement the total intake of Iron exceeded 100% of RDA. We also found majority of food items, except seaweeds, fruits and vegetables, were negatively correlated with maternal stress during three trimesters. Additional support system projected by professionals in health-care field could mediate maternal stress and lead to healthy pregnancy outcome.
        4,300원