• Asian-Australasian Journal of Animal Sciences
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• 제30권10호
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• pp.1382-1387
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• 2017

Objective: During the last decade, genetic evaluation of dairy cows using longitudinal data (test day milk yield or 305-day milk yield) using random regression method has been officially adopted in several countries. The objectives of this study were to estimate covariance functions for genetic and permanent environmental effects and to obtain genetic parameters of 305-day milk yield over seven parities. Methods: Data including 60,279 total 305-day milk yield of 17,309 Iranian Holstein dairy cows in 7 parities calved between 20 to 140 months between 2004 and 2011. Residual variances were modeled by homogeneous and step functions with 7 and 10 classes. Results: The results showed that a third order polynomial for additive genetic and permanent environmental effects plus a step function with 10 classes for the residual variance was the most adequate and parsimonious model to describe the covariance structure of the data. Heritability estimates obtained by this model varied from 0.17 to 0.28. The performance of this model was better than repeatability model. Moreover, 10 classes of residual variance produce the more accurate result than 7 classes or homogeneous residual effect. Conclusion: A quadratic Legendre polynomial for additive genetic and permanent environmental effects with 10 step function residual classes are sufficient to produce a parsimonious model that explained the change in 305-day milk yield over consecutive parities of Iranian Holstein cows.

• Animal Bioscience
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• 제35권11호
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• pp.1649-1655
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• 2022

Objective: The primary objective of this study was to determine the genetic parameters for reproductive traits among Large White pigs, including the following traits: total number born (TNB), number born alive (NBA), litter birth weight (LBW), average birth weight (ABW), gestation length (GL), age at first service (AFS) and age at first farrowing (AFF). Methods: The dataset consisted of 19,036 reproductive records from 4,986 sows, and a multi-trait animal model was used to estimate genetic variance components of seven reproductive traits. Results: The heritability estimates for these reproductive traits ranged from 0.09 to 0.26, with the highest heritability for GL and AFF, and the lowest heritability for NBA. The repeatabilities for TNB, NBA, LWB, ABW, and GL were ranged from 0.16 to 0.34. Genetic and phenotypic correlations ranged from -0.41 to 0.99, and -0.34 to 0.98, respectively. In particular, the correlations between TNB, NBA and LBW, between AFS and AFF, exhibited a strong positive correlation. Furthermore, for TNB, NBA, LBW, ABW, and GL, genetic correlations of the same trait between different parities were moderately to strongly correlated (0.32 to 0.97), and the correlations of adjacent parities were higher than those of nonadjacent parities. Conclusion: All the results in the present study can be used as a basis for the genetic assessment of the target population. In the formulation of dam line selection index, AFS or AFF can be considered to combine with TNB in a multiple trait swine breeding value estimation system. Moreover, breeders are encouraged to increase the proportion of sows at parity 3-5 and reinforce the management of sows at parity 1 and parity ≥8.

• Animal Bioscience
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• 제36권12호
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• pp.1785-1795
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• 2023

Objective: This study was to estimate heritabilities, additive genetic correlations, and phenotypic correlations between number of piglets born alive (NBA), litter birth weight (LTBW), number of piglets weaned (NPW) and litter weaning weight (LTWW) in different parities of Landrace (L), Yorkshire (Y), Landrace×Yorkshire (LY), and Yorkshire×Landrace (YL) sows in a commercial swine operation in Northern Thailand. Methods: Two models were utilized, a single trait repeatability model (RM) and a multiple trait animal model (MTM). The RM assumed reproductive records from different parities to be repeated values of the same trait, whereas the MTM assumed these records to be different traits. The two models accounted for the fixed effects of farrowing year-season, genetic group of the sow, heterosis, and age at first farrowing, and the random effects of sow, boar, and residual. Results: Heritability estimates from RM were 0.02±0.01 for NBA, 0.10±0.01 for LTBW, 0.04±0.01 for NPW, and 0.11±0.01 for LTWW. Heritability estimates from MTM fluctuated across parities, ranging from 0.04±0.01 in parity 2 to 0.09±0.02 in parity 4 for NBA, 0.07±0.02 in parity 2 to 0.16±0.02 in parity 3 for LTBW, 0.04±0.02 in parity 4 to 0.08±0.01 in parity 1 for NPW, and 0.16±0.02 in parity 1 to 0.20±0.02 in parity 2 for LTWW. Additive genetic correlation estimates from MTM were also variable, ranging from 0.29±0.24 between NBA in parity 1 and NBA in parity 2 to 0.99±0.05 between LTWW in parity 3 and LTWW in parity 4. Conclusion: The findings of this study highlight the advantage of using MTM for the genetic improvement of reproductive traits in swine and contribute to the development of sustainable swine breeding programs in Thailand.

• Asian-Australasian Journal of Animal Sciences
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• 제31권3호
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• pp.410-420
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• 2018

Objective: This experiment was to evaluate the effects of the dietary energy levels on the physiological parameters and reproductive performance during gestation over three parities in sows. Methods: A total of 52 F1 gilts ($Yorkshire{\times}Landrace$) were allotted to one of four dietary treatments using a completely randomized design. The treatments contained 3,100, 3,200, 3,300, or 3,400 kcal of metabolizable energy (ME)/kg diet but feed was provided at 2.0, 2.2, and 2.4 kg/d in the first, second and third parity, respectively. Results: The body weight and body weight gain during gestation increased as the dietary energy level increased (p<0.05, and p<0.01) in the first parity. In the second parity, the body weight of sows was the lowest (p<0.05) when 3,100 kcal of ME/kg treatment diet was provided. The body weight was higher as the dietary energy level increased (p<0.05) during the gestation period in the third parity. During lactation, the voluntary feed intake of lactating sows tended to decrease when gilts were fed higher energy treatment diet (p = 0.08) and the body weight, body weight gain were increased by dietary energy level during gestation (p<0.05). Backfat thickness was not affected by dietary treatment during the gestation period in three parities, interestingly backfat change from breeding to d 110 of gestation was higher as the dietary energy level increased at the first parity (p<0.05). When gilts were fed 3,400 kcal of ME/kg treatment diet a higher number of weaning piglets was observed in the first parity (p<0.05). The highest culling rate (69%) was seen when gestating sows were fed 3,100 kcal/kg ME treatment diet during three parities. Conclusion: In conclusion, the adequate energy intake of gestating sows should be 6,400 or 6,600 kcal of ME/d, 7,040 or 7,260 kcal of ME/d, and 7,680 or 7,920 kcal of ME/d for parity 1, 2, and 3, respectively.

• 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%).

• 한국가축번식학회지
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• 제13권1호
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• pp.1-6
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• 1989

A field survey was conducted to obtain the data on reproductive performation of Korean native cattle. The data for this study were taken from 6,461 breeding records of cows raising at general farms in 8 Hanwoo(native cattle) pure breeding areas from June, 1984 through November, 1985. The recycling rate within 30 days, 31 to 60 days, and 61 to 90 days postpartum was 7.5%, 40.0%, and 32.8%, and it amounted to 80.3%, while the non-recyling rate up to 120days postcalving was 8.4%. Conception rate according to insemination(AI) frequencies was 65.7% at 1st AI, 21.3% at 2nd AI, and 8.4% at 3rd AI, respectively. It amounted to 95.4% up to 3rd AI. Clving rate during the spring time was the highest, 39.6%, and tended to be reduced according to summer(31.6%), autumn (16.3%), and winter (12.5%). Spring and summer were the highest seasons for pregnancy and their gestation rates are 33.7% in spring and 39.2% in winter, respectively. The days from calving to estrus and conception, and calving interval of the cows, which calved two or three times, tended to be reduced. However, the more parities, the more they are extended. According to parities, gestation length and services per conception showed irregular tendencies.

• 한국가축번식학회지
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• 제16권3호
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• pp.261-267
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• 1992

The reproductive performance of SPF ICR mice under single paired mating were examined to get reproductive background data and to establish single paired rotational mating system. The results obtained were as follows : average litter size was 15.4$\pm$2.0 heads ; average weaning rate was 95.7$\pm$4.9% ; sex ratio(male/female) was 1.09$\pm$0.26 ; aveage delivery interval was 23.0$\pm$2.4 days. It was given the largest litter size at the age of 121~150 days and in 2nd~4th parities, but at the age of under 90 days and in 1st parity weaning rate and delivery interval were higher and shorter than those of the other ages and parities, respectively. In sex ratio, the number of male litters was slightly increased from that of female litters. The weaning rate of litters from dams which nuresed 12 litters was the highest among those of different litter sizes, and it was decreased dependent upon increment of litter size. There were no difference among 4 groups for reproductive performance, therefore the present study could have important sources for animal breeders who produce mice using the single paired rotational mating system.

• 호남수학학술지
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• 제30권4호
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• pp.733-741
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• 2008

Let T be Gauss transformation on the unit interval defined by T (x) = ${\frac{1}{x}}$ where {x} is the fractional part of x. Gauss transformation is closely related to the continued fraction expansions of real numbers. We show that almost every x is mod M normal number of Gauss transformation with respect to intervals whose endpoints are rational or quadratic irrational. Its connection to Central Limit Theorem is also shown.

• Asian-Australasian Journal of Animal Sciences
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• 제31권6호
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• pp.820-826
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• 2018

Objective: The purpose of this retrospective study was to investigate the relationship between temperature-humidity index (THI), season, and conception rate (CR) of Holstein cows in central Taiwan. Methods: The mean performance and number of observations were statistically evaluated for various parameters, including age at first service, number of days open, gestation length, CR, and calving interval for different parities. Results: The results indicate that the mean age at first service was 493.2 days; the gestation length was similar across all cows of different parities, ranging from 275.1 to 280.7 days. The overall CR of all inseminations was significantly lower in multiparous cows ($47.26%{\pm}0.22%$) than in heifers ($57.14%{\pm}0.11%$) (p<0.05). At THI>72 and during the hot season (from June to November), CRs for multiparous cows were significantly reduced compared to that for heifers, while the ratio remained unchanged among heifers for all seasons. Conclusion: To achieve a high CR, lactating cows should be bred in winter and spring (from December to May) from the start of the seasonal breeding program, whereas the heifer should be allowed to breed in summer and fall under the subtropical climate in Taiwan.

• 한국수정란이식학회지
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• 제31권3호
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• pp.273-279
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• 2016

한우는 한국 고유재래종으로 가장 많이 사육되고 있으나 번식성적에 대한 자료는 제한적이다. 본 연구는 총 163,613두의 번식성적에 대하여 통계 분석하였다. 산차 및 계절별로 분만 간격과 임신기간의 차이는 없었으나 매년 분만간격이 증가하고 있었다. 또한 생시 체중이 23 kg 이었을 때 생애 번식성적이 가장 우수 하였다.