• Asian-Australasian Journal of Animal Sciences
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• 제22권9호
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• pp.1328-1333
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• 2009

To evaluate different housing systems, 80 gilts were randomly allocated at puberty to four treatments: i) sow stall in gestation followed by farrowing crate (SC), ii) group housing with individual feeding in gestation followed by farrowing crate (GC), iii) ESF (Electronic Sow Feeding) system in gestation followed by farrowing crate (EC), and iv) ESF system followed by group farrowing pen (EG). The results showed that stalled sows had a longer interval between puberty and second estrus (p<0.001). The sows kept in the ESF system gained more body weight (p<0.01) and backfat (p<0.05) prior to service, and more backfat during gestation (p<0.05), but also had greater backfat losses in the subsequent lactation (p<0.01). Sows changing from loose housing to confinement at farrowing had longer gestation length (p<0.001). Total litter size did not differ significantly between gestation treatments, but the number of stillborn piglets was significantly higher in the SC treatment (p<0.01). After weaning, SC sows had the longest interval for rebreeding (p<0.001). Some EG sows came into heat before weaning, giving this treatment the shortest interval. These results indicate that gestation confinement in sow stalls had several detrimental effects on sow performance relative to group housing.

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.633-639
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• 2008

The genetic relationship of gestation length (GL) with birth and weaning weight (BW, WW) was investigated using data collected from the Hanwoo Experiment Station, National Institute of Animal Science, RDA, Republic of Korea. Analytical mixed models including birth year‐season, sex of calf, linear and quadratic covariates of age of dam (days) and linear covariate of age at weaning (days) as fixed effects were used. Corresponding restricted maximum likelihood (REML) and Bayesian estimates of variance components and heritability were obtained with two models; Model 1 included only direct genetic effect and Model 2 included direct genetic, maternal genetic and permanent environmental effect. All the genetic parameter estimates from REML were corresponding to the Bayesian estimates. Direct heritability estimates for GL, BW, and WW were 0.48, 0.33 and 0.25 by Model 1. From Model 2, direct and maternal heritability estimates were 0.38 and 0.03 for GL, 0.14 and 0.05 for BW, and 0.08 and 0.05 for WW. Genetic correlation estimates between direct and maternal effects were 0.05 for GL, 0.59 for BW, and 0.52 for WW. Estimates of direct genetic correlation between GL and BW (WW) were 0.44 (0.21). Positive genetic correlation of GL with BW and WW imply that selection for greater BW or WW would lead to prolonged gestation length.

• Asian-Australasian Journal of Animal Sciences
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• 제18권7호
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• pp.909-914
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• 2005

This study was conducted to estimate phenotypic and genetic parameters of body condition score (BCS) and reproductive traits in Hanwoo cows. DFREML procedures were applied to obtain variance-covariance components and heritability estimates with single or two-trait models. Estimates of phenotypic correlations of BCS at service with BCS at calving was 0.16 and 0.26 with calving interval, 0.08 with gestation length, and 0.06 with number of services per conception, respectively. Estimates of phenotypic correlation of BCS at calving was 0.10 with calving interval, 0.13 with gestation length, and 0.10 with number of services per conception, respectively. Estimates of phenotypic correlation were low and negative, -0.11 between calving interval and gestation length and -0.13 between gestation length and number of services per conception. Estimates of direct genetic correlation were -0.06, between BCS at service and BCS at calving, 0.37 between BCS at service and BCS at weaning, and -0.18 between BCS at calving and BCS at weaning. Estimates of direct genetic correlation of days from calving to the 1st service were 0.17 with number of services per conception and -0.21 with BCS at service. Estimates of direct genetic correlation for BCS at calving were -0.02 with number of services per conception and -0.08 with BCS at service. Estimates of direct genetic correlation for BCS at weaning were 0.02 with number of services per conception and -0.07 with BCS at service. Estimates of direct heritability from single trait analyses were 0.13 for BCS at service, 0.20 for BCS at calving, 0.02 for BCS at weaning, and 0.20 for number of service per conception, respectively. Estimates of direct heritability were 0.20 for birth weight and 0.10 for weaning weight.

• 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.

• 한국수정란이식학회지
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• 제8권2호
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• pp.97-103
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• 1993

This study was conducted to determine the main effects of the parity and farrowing season on gestation length and newborn pigs on the basis of the data obtained from 234 litters of Landrace breeds raised at an integrated swine farm in Kyunggy province from January 1991 to December 1992. The results obtained are summarized as follows ; 1. The average gestation length was 115.37 days, and 114.64 days of 8th parity and over was shorter than those of other parities. 2. The averages of litter size and litter size alive per sow were 9.91 and 9.50 heads. The litter size horn at 1st parity was smaller than at other parities, and the litter size in spring was larger than in summer, autumn or winter. 3. The averages of birth weight per litter and pig were 13.53 kg and 1.37 kg. The effect of farrowing season for each litter weight(p<0.01) and pig weight(p<0.05) at birth was significantly higher in spring than other seasons. 4. Incidence of malformation and stillbirth at birth was 4. 10%, and it at 8th parity and over showed the highest rate(7.50%).

• 한국수정란이식학회지
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• 제26권1호
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• pp.27-32
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• 2011

본 연구는 OPU 유래 한우 수정란을 이식한 대리모의 품종이 임신 기간과 산자의 생시 체중에 미치는 영향을 분석하고자 6~7일차 OPU 유래 한우 체외수정란을 한우와 젖소 대리모에 이식하여 산자를 생산하였다. 1. 대리모에 따른 평균 임신 기간(젖소: $284.4{\pm}9.8$일, 한우: $280.9{\pm}6.2$일)과 산자의 생시 체중(젖소: $27.70{\pm}7.92\;kg$, 한우: $23.56{\pm}3.75\;kg$)에서 유의적인 차이가 없었다. 2. 임신 기간은 수송아지를 생산한 대리모(한우: $283.8{\pm}6.7$일, 젖소: $287.3{\pm}8.9$일)가 암송아지(한우: $277.3{\pm}3.3$일, 젖소: $280.1{\pm}9.9$일)를 임신한 대리모보다 유의적으로 길었다(p<0.05). 단태에서도 수송아지를 분만한 대리모의 임신 기간이 유의적인 차이가 있었다(p<0.05). 3. 산자의 성별에 따른 생시 체중은 암송아지(한우 대리모: $21.5{\pm}3.8\;kg$, 젖소 대리모: $21.5{\pm}6.1\;kg$)보다 수송아지(한우 대리모: $25.2{\pm}3.1\;kg$, 젖소 대리모: $32.3{\pm}6.0\;kg$)가 무거웠으며, 수송아지의 경우 품종간 유의적 차이를 보였다. 단태에서도 수송아지가 유의 하 게 높았다(p<0.05). 이상의 결과, OPU 유래 수정란을 이식한 대리모의 임신 기간은 대리모의 품종에 따른 차이는 없었으나, 분만된 산자의 성별에 따라 유의적인 차이기 있었다. 산자의 생시 제중은 수송아지가 유의적으로 높은 생시 체중을 보였고 임신 기간도 수송아지를 분만했을 때 유의적으로 길었다. 수송아지의 경우 품종간의 차이를 보였는데, 이러한 결과는 수정란이식에 의해 생산되는 송아지의 생시 체중과 대리모의 임신 기간은 태아의 품종보다 대리모의 품종이 영향을 미치는 것으로 판단된다. 본 연구에서 젖소 대리모가 한우 대리모보다 번식 적령기의 체중이 무거우므로 대리모의 품종이 산자의 생시 체중에 영향을 미치는 것으로 판단된다.

• 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.

• Journal of applied mathematics & informatics
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• 제5권3호
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• pp.597-606
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• 1998

In the present study we consider a mathematical model of a non-interactive type autotroph-herbivore system in which the amount of autotroph biomass consumed by the herbivore is assumed to follow a Holling type II functional response. We have also incorpo-rated discrete time delays in the numerical response term to represent a delay due to gestation and in the recycling term which represent a delay due to gestation and in the recycling term which represents the time required for bacterial decomposition. We have derived con-dition for global asymptotic stability of the model in the absence of delays. Conditions for delay-induced asymptotic stability of the steady state are also derived. The length of the delay preserving stability has been estimated and interpreted ecologically.

• Asian-Australasian Journal of Animal Sciences
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• 제15권12호
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• pp.1680-1685
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• 2002

Reproductive data collected from more than 20,000 Japanese Black cows of Hyogo and Shimane Prefectures were analyzed. Averages of age at first calving, gestation length, days open and calving interval were 25.1 mo, 289 d, 112 d and 401 d, respectively. Variance components were obtained by REML procedure and the heritability estimate of age at first calving was 0.22. In gestation length the heritability estimate was 0.40 and no permanent environmental effect was estimated. Estimated variance components of calving interval were similar to those of days open and the heritability and repeatability of calving interval were 0.05 and 0.09, respectively. Random farm effects accounted for approximately 10% of phenotypic variations in all traits. Genetic and farm correlations between age at first calving and calving interval were 0.27 and 0.39, respectively. It was found that temporary environment was an important source of variation for calving intervals of Japanese Black.

• Asian-Australasian Journal of Animal Sciences
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• 제23권10호
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• pp.1282-1290
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• 2010

The study was carried out to assess the developmental abnormalities induced by Cytotec in mice during intrauterine life. Pregnant mice were exposed to a single dose of 0, 0.02, 0.04, 0.06, 0.08 and $0.1{\mu}g$/g BW on day 8 of gestation. Fetuses were recovered on day 18 of gestation. These fetuses were subjected to morphological and morphometric studies. Morphological studies showed abnormalities like anophthalmia, microophthalmia, micromelia and syndactyly. In addition to these, resorptions were also encountered in the higher dose groups. Morphometric analysis showed an overall reduction in body weight, crown rump length, brain and eye circumference, pinna and snout size, length of fore and hind limb and tail size with a significant difference (p<0.001) compared to controls. The outcomes of histological studies revealed some brain defects like hydrocephaly, enlarged third ventricle and undifferentiated ectoneural cells and abnormalities of the heart included right auricle thrombosis and degeneration of trabecular zone.