• Asian-Australasian Journal of Animal Sciences
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• 제14권6호
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• pp.771-776
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• 2001

A pregnant-induced clone was identified by differential screening from a cDNA library of bovine mammary gland. The clone was identified as a cDNA encoding a polyadenylate binding protein 1 (PABP). The cDNA clone had a total length of 1,911 nucleotides coding for 636 amino acids. The nucleotide sequence of the bovine PABP was 95% and 94% identical to those of human and mouse species, respectively. Comparison of the deduced amino acid sequences of bovine PABP with those of human species showed 100% identity. Induction of the PABP mRNA was observed in bovine mammary tissues at pregnant 7 and 8 months compared to virgin, lactating and involuted states. Expression of the PABP gene was examined in mammary epithelial HC11 cells at proliferating, differentiated and apoptotic conditions. The mRNA levels of PABP gene were similar between proliferating and differentiated cells, but expression levels were very low in apoptotic cells compared to other conditions. Results demonstrate that the PABP gene is induced during pregnancy at which stage mammary epithelial cells are actively proliferating.

• 한국가축번식학회지
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• 제12권1호
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• pp.15-19
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• 1988

This study was carried out to investigate the fertility and farrowing date in post-weaning sows using PG600 and inseminated with frozen semen. A total of 48 sows of Landrace, Large White and Duroc after 7-week lactation were used at the Chungnam Provincial Animal Breeding Station. The results obtained were summarized as follows: 1. Motility had no significant differences between the breeds, but NAR acrosome was highest in Landrace, followed by Duroc and Large White(p<.01). 2. Interval from weaning to estrus and length of estrus were, respectively, 3.7 days and 52.6hours of sows treated with PG600, and 6.5 days and 53.8 hours for control sows. The average interval from weaning to onset of estrus was significantly(p<.01) shorter by 2.8 days in PG600 treated sows compared to control sows. 3. In Landrace, Duroc and Large White, farrowing rate and number of pigs born alive per litter were 55.0%, 10.0; 43.8%, 8.1; and 16.7%, 3.5, respectively. Average pig weight at birth and survival rate at 56 days had no significant differences between the breeds. 4. Farrowing rate, number of pigs born alive per litter, average pig weight at birth and survival rate at 56 days were, respectivey, 45.8%, 101, 1.56kg and 94.5% for sows treated with PG600, and 37.5%, 7.0, 1.66kg and 93.8% for control sows. Sows treated with PG 600 had an average of 3.1 more pigs at farrowing compared to control sows.

• Asian-Australasian Journal of Animal Sciences
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• 제10권1호
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• pp.75-78
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• 1997

Season is very important as it defines the contemporaries for sire and cow evaluation. An attempt is made for defining season for animal model evaluation of Sahiwal animals, using 1,227 records from 730 cows. Cows were required to have a lactation length of 305-days. Ten different combinations of months for two, four, five or other seasons were tried. The other fixed effect in the model was age defined within parity. The random effects were permanent environment and animal's breeeding value along with the residual effects. A single trait animal model was used where all known relationships of an animal were incorporated in a relationship matrix. The error variance from the fitted model decreased as the number of year-season combinations increased, indicating a month-year model to be more appropriate. This, on the other hand, decreased the number of contemporaries for certain subclasses to a minimum of one, making the bull comparisons invalid. Use of a two season scenario, with winter (November through February) and summer (March through October) was better than the other combinations in terms of error variance of the fitted model and the number of lactations represented in any year-season subclass.

• Asian-Australasian Journal of Animal Sciences
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• 제21권6호
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• pp.769-775
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• 2008

This study was on the relative net income (RNI) for 18,286 Iranian Holstein cows from 799 herds, with first freshening between 1991 and 2000. Two kinds of production system, which differed mainly in milk pricing system and feed cost, were considered. Four different models adopted from the literature were examined to find the optimum model. They differed by the cost of rearing and growth after first calving and they needed different amounts of economic data at the farm level. Results showed that four measures of RNI were highly correlated (>0.96) and could be used equally to measure lifetime profitability of cows. Therefore, in herds without a regular system for recording economic and management data, use of the simplest model is recommended. Multiple regression analysis revealed that RNI was affected by age at first freshening, milk yield and days of productive life (DPL), regardless of production system, and a similar breeding goal could be defined for the two systems. Multiple regression analysis of RNI showed that in order to obtain an unbiased estimate of economic value for DPL, the per day milk yield, not total lifetime milk yield, should be included in the regression model along with DPL. Regression analysis suggested that it is possible to predict RNI using information on age at first freshening along with the length of first lactation and per day milk yield with a coefficient of determination ranging from 0.44 to 0.47.

• 한국축산식품학회지
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• 제25권3호
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• pp.328-332
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• 2005

The effect of k-casein (k-CN) variant on milk production traits (milk yield, fat yield, protein yield, fat percentage and protein percentage) was estimated for 568 Holstein cows in the first lactation. The k-CN valiant were determined by PCR-RFLP (restriction fragment length polymorphism) technique at the DNA level. Single trait linear model was used for the statistical analysis of the data. Result of this study indicated that k-CN variant affected significantly milk yield (P<0.05) and protein yield (P<0.01). Animals with the BB variant produced 622kg milk more and had protein yield higher by 32kg compared with animals with the AA variant No associations between the k-CN variants and other milk production trait were found. Therefore, milk and protein yield may be improved through milk protein typing by increasing the frequencies of k-CN B variant in dairy cattle population. In cheese making, it will be also preferable to have milk with the B variant of k-CN, which gives higher yield having a better quality than the A variant milk.

• Journal of Nutrition and Health
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• 제26권6호
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• pp.758-771
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• 1993

This study was conducted longitudinally following the total lipid and cholesterol content, fatty acids composition and Vitamin E content in human milk from 2-5 days to 12 weeks postpartum of 45 lactating Korean mothers. All samples were from well-defined subjects and uniform collection procedures were used. Total lipid concentration increased from 1.98g/dl at 2-5 days to 3.09g/dl at 12 weeks postpartum. However, there was a large variation in the concentration of total lipids. Total cholesterol concentration tended to decrease from 20.68mg/dl at 2-5days to 17.19mg/dl at 12 weeks. In comparison with transitional and mature milk, human colostrum was characterized by a lower percentage of saturated fatty acids including medium chain length fatty acids and a higher percentage of monounsatureated fatty acids and polyunsaturated fatty acids. Therefore, the P/S and M/S ratios of human milk lipids decreased significanlty during lactation. P/M/S ratio of colostrum changed from 0.38 : 0.84 : 1.00 at 2-5 days to 0.29 : 0.61 : 1.00 at 12 weeks of mature milk. Total tocopherol concentration decreased significantly from 833 ug/dl at 2-5 days to 300 ug/dl at 12 weeks.

• Journal of Animal Science and Technology
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• 제65권1호
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• pp.197-208
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• 2023

The objective of this study was to investigate the effects of a traditional dry period (60 d) versus a no dry period (0 d) on the milk production, physiological response, and metabolic status of dairy cows exposed to heat stress during the transition period. Holstein dairy cows (n = 15) with similar expected calving dates were randomly assigned to two different dry period lengths: (1) no dry period (n = 7) and (2) a traditional dry period of 60 days (n = 8). All cows were studied from 8 weeks before expected calving to 10 weeks after calving and experienced heat stress during the transition period. The results showed that cows with no dry period decreased their milk yield in subsequent lactation, but compensated for the loss of milk yield accounted for by additional milk yield before calving. The energy balance at postpartum was improved in cows with no dry period compared to cows with a traditional dry period. There were no significant differences in the physiological response and blood metabolites at postpartum between the dry period lengths of dairy cows exposed to heat stress during the transition period. Taken together, our results showed that omitting the dry period improved the milk production and metabolic status of dairy cows exposed to heat stress during the transition period.

• Asian-Australasian Journal of Animal Sciences
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• 제15권6호
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• pp.777-782
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• 2002

Reciprocal effects among local breeds and additive and heterosis effects were estimated for total milk production per lactation (TLP), lactation length (LL) and daily milk yield (DMY). Procedures for an optimum crossbreeding system were examined by comparing various crossbred combinations. Three data sets were chosen from the total records collected from 1962 to 1997. Data set I with a total of 5,938 records composed of 9 breed groups for reciprocal crosses, data set II with a total of 6,064 records composed of 5 breed groups for additive and heterosis effects and data set III with a total of 10,319 records composed of 42 breed groups for optimum crossbreeding system were analyzed. The least squares ANOVA was used. The reciprocal crosses between Red Sindhi and the Bangladeshi Local showed significant difference. When the Red Sindhi was used as cow, the cross was superior to the opposite in terms of the three performance traits. The results showed that additive breed effects on both TLP and DMY were positive and highly significant between Bos indicus and Bos taurus, whereas the individual heterosis effects were not significant. In general, any local breeds were improved two to three times by crossing with the Friesian once or twice. However, the effect was reduced when the grading up with the Friesian was repeated more than twice. On the other hand, when the local breed was crossed with the other breeds such as Holstein and Jersey, the improvement of TLP was less. Crossing the F1 cows with the Friesian bull gave further improvement. Almost the same trends were found also for LL and DMY. The local breeds and their crosses are raised mainly for draft animals, then it is recommended that the crossbreds between the local cows and Friesian are used for dairy purposes and more than 75% Friesian blood is used for beef.

• Journal of Animal Science and Technology
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• 제50권3호
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• pp.285-292
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• 2008

본 연구는 국제적인 경쟁력을 갖기 위한 젖소개량방법으로 체세포를 활용하는 방법을 모색하고자 선형심사 자료에서 유방염에 관련된 형질을 이용하여 새로운 선발지수를 개발하기 위한 단계로 국내 젖소집단의 체세포점수 분포와 변화추이를 분석해보고 연령, 분만계절, 비유단계의 환경효과를 구명하고 유방관련 형질과의 유전상관과 유전력을 구하여 기초자료로 활용하고자 본 연구를 진행하였다. 분석은 유우군 능력검정을 통하여 2000년부터 수집된 자료를 이용하였고 자료는 1산차 기록을 갖는 10,929개체의 290,144 검정일 기록과 37,723개의 유방형질 기록을 이용하였다. 분석에 이용된 유방형질은 전유방붙음성, 뒷유방높이, 뒷유방너비, 유방깊이, 앞유두길이의 형질이며 체세포 점수간의 표현형상관과 유전상관을 구하고 분산성분을 추정하였으며 개체모형을 이용하여 표현형상관과 유전상관을 분석하였다. 분석에 이용된 모형은 개체모형으로 DF-REML방식을 이용하여 추정하였고 유방깊이와 앞유두길이의 유전력은 0.23, 0.22로 체세포점수의 유전력은 0.08로 분석되었다. 유방형질과 체세포점수간의 표현형상관은 －0.03~－0.06으로 낮게 나타났으며 높은 유방붙음성을 갖을수록 낮은 체세포점수를 보였다. 체세포점수와 유방깊이, 체세포점수와 앞유두길이의 유전상관은 부의 상관을 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권2호
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• pp.160-165
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• 2007

Dispersion parameters for the number of piglets born alive were estimated using a repeatability and random regression model. Six sow breeds/lines were included in the analysis: Swedish Landrace, Large White and both crossbred lines between them, German Landrace and their cross with Large White. Fixed part of the model included sow genotype, mating season as month-year interaction, parity and weaning to conception interval as class effects. The age at farrowing was modelled as a quadratic regression nested within parity. The previous lactation length was fitted as a linear regression. Random regressions for parity on Legendre polynomials were included for direct additive genetic, permanent environmental, and common litter environmental effects. Orthogonal Legendre polynomials from the linear to the cubic power were fitted. In the repeatability model estimate of heritability was 0.07, permanent environmental effect as ratio was 0.04, and common litter environmental effect as ratio was 0.01. Estimates of genetic parameters with the random regression model were generally higher than in the repeatability model, except for the common litter environmental effect. Estimates of heritability ranged from 0.06 to 0.10. Permanent environmental effect as a ratio increased along a trajectory from 0.03 to 0.11. Magnitudes of common litter effect were small (around 0.01). The eigenvalues of covariance functions showed that between 7 and 8 % of genetic variability was explained by individual genetic curves of sows. This proportion was mainly covered by linear and quadratic coefficients. Results suggest that the random regression model could be used for genetic analysis of litter size.