• Asian-Australasian Journal of Animal Sciences
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• 제17권2호
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• pp.179-182
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• 2004

The polymorphism of the locus FSHRB in intron6-Exon7 of FSHR gene was investigated by PCR-RFLPs in Erhualian, Large White and Landrace${\times}$Large White; The association of polymorphism and litter size was analyzed by using SAS. The results showed that 1) the polymorphism of the locus FSHRB was significantly associated with litter size; 2) the total born number (TBN) and number born alive (NBA) of the sows with BB genotype were increased (p<0.05) with additive effects of 1.02-1.42 and 1.04-1.27 pigs per litter, respectively; 3) among the sows with genotype AA, AB or BB, there was an insignificant difference in born weight and weaning weight. This gene may be an effective potential tool used in conjunction with traditional selection methods.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제32권7호
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• pp.949-955
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• 2019

Objective: The present study was to investigate the association of polymorphisms in exon-9 of the bone morphogenetic protein receptor-1B (BMPR-1B) gene (C864T) with litter size in 240 Dorset, 232 Mongolian, and 124 Small Tail Han ewes. Methods: Blood samples were collected from 596 ewes and genomic DNA was extracted using the phenol: chloroform extraction method. The 304-bp amplified polymerase chain reaction product was analyzed for polymorphism by single-strand conformation polymorphism method. The genotypic frequency and allele frequency of BMPR-1B gene exon-9 were computed after sequence alignment. The ${\chi}^2$ independence test was used to analyze the association of genotypic frequency and litter size traits with in each ewe breed, where the phenotype was directly treated as category. Results: The results indicated two different banding patterns AA and AB for this fragment, with the most frequent genotype and allele of AA and A. Calculated Chi-square test for BMPR-1B gene exon-9 was found to be more than that of p value at the 5% level of significance, indicating that the population under study was in Hardy-Weinberg equilibrium for all ewes. The ${\chi}^2$ independence test analyses indicated litter size differences between genotypes was not the same for each breed. The 304-bp nucleotide sequence was subjected to BLAST analysis, and the C864T mutation significantly affected litter size in singletons, twins and multiples. The heterozygosity in exon-9 of BMPR-1B gene could increase litter size for all the studied ewes. Conclusion: Consequently, it appears that the polymorphism BMPR-1B gene exon-9 detected in this study may have potential use in marker assisted selection for litter size in Dorset, Mongolian, and Small Tail Han ewes.

• Journal of Animal Science and Technology
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• 제49권3호
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• pp.303-308
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• 2007

등지방을 포함한 산육형질과 번식 및 산자형질간의 관계를 규명하기 위하여 경남흑돈(버크셔)의 자료를 분석하였다. Pearson 상관의 추정에서 등지방은 번식형질과 -0.24～-.26을 나타냈다. 유전적 관계를 조사하기 위한 초분만일령, 초분만일령과 첫 분만을 위한 종부횟수에 관한 유전상관 추정은 자료의 부족으로 추정치의 변동이 많고 폭이 컸다. 등지방과 산자형질과는 낮은 Pearson 상관을 보였지만 총산자, 생존산자, 생시복체중, 이유복체중의 유전상관계수가 각각 .21, .24, .11, .07으로 조사되어 유전적 상관이 더 높게 조사되어 등지방의 개량이 산자능력을 감소시킬 수 있다. 90kg 도달일령과 총산자, 생존산자, 생시복체중, 이유복체중과의 유전상관 계수는 .14, .17, .09 그리고 0.0으로 각각 조사되어 산육능력이 우수할수록 산자능력의 감소를 의미하고 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권6호
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• pp.789-792
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• 2006

Two separate trials were conducted to determine the effects of uterine priming prior to first breeding and quantify any changes in the reproductive efficiency of gilts. In trial I twelve (12) gilts were randomly assigned to 3 treatments:T1:infusion of distilled water (control), T2: single infusion of killed semen (KS1), and T3: double infusion of killed semen (KS2). Each treatment had 4 breeding gilts which were bred by natural insemination (NI). In trial II, another set of 12 breeding gilts were randomly allotted to the same treatments and were subsequently bred by artificial insemination (AI). Infusions, through the use of AI catheters, were done during the $2^{nd}$ estrous cycle for T1 and T2, whereas infusions for T3 were made during the $1^{st}$ and $2^{nd}$ cycles. Regular breeding was subsequently made during the $3^{rd}$ estrous cycle. All gilts that returned to cycle were rebred within the 30-day period. In trial I (natural breeding), total piglets born was higher (p<0.05) in T2 (12.75 piglets) and T3 (11.75 piglets) than in the control (10.5 piglets). T3 obtained the highest (p<0.05) litter size (10.25 piglets) and heaviest litter weight (74.12 kg) at 28 days weaning, followed by T2 (9.80 piglets and 65.0 kg, respectively). The control yielded the lowest (p<0.05) litter size (7.50) and the lightest litter weight (47.00 kg) at weaning. For Trial II gilts (artificially inseminated), T3 gave higher (p<0.05) litter size born alive (10.88 piglets), total piglets born (11.72 piglets) and live litter weight at birth (15.30 kg) than those of T2 and the control. These results indicate that prebreeding intrauterine infusion of killed boar semen, either single or double, improved the reproductive performance of gilts.

• Asian-Australasian Journal of Animal Sciences
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• 제13권11호
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• pp.1638-1652
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• 2000

Prolific females require better nutrition and feeding practice because of larger litter size and the substantial decline in body fat. Life-time pig output will be compromised if body protein and fat are not properly managed. First litter females are especially vulnerable because they can loose ${\geq}15%$ of whole-body protein. Conservation of body protein mass during first lactation minimizes wean to estrus interval and increases second litter size (up to 1.2 pigs). The ability to influence litter-size by amino acid nutrition is a new dimension in our understanding. A P2 fat depth below 12 mm at farrow and below 10 mm at wean compromised wean to estrus interval (>2 d) and next litter size (0.5 to 1.5 pigs) in sows. It is now clear that a 'modest' excess of feed during the first 72 h of pregnancy decreases embryo viability so that the potential for an increased litter size at birth is not realized. The capacity for milk production by prolific young sows is 25% higher than the standard used previously (NRC, 1988). First litter females averaged 9.82 kg milk/d for a 21 d lactation. Second and third litter counterparts averaged 10.35 kg/d. Milk production was 95% of peak by 10 d of lactation and sows were in greatest negative energy and lysine balance during the first 6 d. Nearly 45% of the total loss in body protein occurred within the first 6 d, but this could reduced to 30-35% by using a more aggressive feeding strategy after parturition. There appear to be 2 phases in lactation for lysine need (d 2-12 vs 12-21). Feeding to the higher level alleviates the second litter size decline. The lysine requirement for lactation can be predicted with accuracy, but we are not able to predict the second limiting amino acid. Mammary uptake of valine relative to lysine and recent work with practical diets suggest that the recent NRC (1998) pattern is realistic and that threonine and valine could be co-limiting for corn-soy diets for prolific sows nursing 10-11 pigs. Empirical studies are needed to refine the ideal pattern so that synthetic lysine can be used with more confidence. Milk fat output for the elite sow is extraordinary and poses an unnecessarily high energetic cost. Methods that reduce mammary fat synthesis will benefit the sow and may enhance piglet growth.

• Journal of Animal Science and Technology
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• 제45권1호
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• pp.33-40
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• 2003

본 연구는 혈장의 insulin-like growth factor (IGF)-I과 IGF-II 농도와 산자수 및 비유성적과의 관계를 구명하고자 착수되었다. 분만주가 비슷한 미경산 및 경산 임신돈 중에서 선발한 총 60두의 순종 Landrace와 Yorkshire 공시돈을 저산자수 (low; <${\mu}$­0.5 SD)와 고산자수 (high; >${\mu}$ + 0.5 SD)-lines로 구분하여 2 (품종) ${\times}$ 2 (line) 요인분석 실험설계 하에 본 실험을 진행하였다. 공시돈은 분만시 모돈당 포유자돈수를 9두로 고정시키고, 3주령 이유시 비유량의 척도로서 총 이유자돈 체중을 측정하였다. 혈액 시료는 임신 90일과 분만 후 15일에 경정맥으로부터 채취하였다. 본 실험기간 중 산자수 및 본 실험기간까지의 평균 산자수는 high-line이 low-line보다 각각 3.7두와 2.4두 많았고 (P< 0.01), 두 품종간 산자수 차이는 없었다. 임신 90일 혈장의 IGF-II 농도는 low-line보다 high-line에서 높았다. 산자수는 임신 90일 IGF-I 농도와 Landrace에서는 부의 상관관계를 나타냈고 (r=－0.46; P<0.05), Yorkshire에서는 부의 상관관계 경향을 나타내어 (r=－0.31; P=0.09) 전체 공시돈에서는 이들 두 변수간 유의적인 부의 상관관계를 보였다 (r=－0.35; P< 0.01). 이유시 모돈당 총 이유자돈 체중은 두 품종간 혹은 두 lines간 차이가 없었다. 이유자돈 체중과 IGF 농도와의 관계는 품종 ${\times}$ 생리적인 생태 조합들간 일정한 경향을 나타내지 않았다. 이상의 결과는 임신 90일 IGF 농도가 임박한 분만시 산자수의 지표가 될 수 있는 가능성을 시사한다.

• Asian-Australasian Journal of Animal Sciences
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• 제4권2호
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• pp.143-150
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• 1991

The data on reproductive performance of 1065 purebred Landrace, 1254 purebred Yorkshire. 553 purebred Duroc and 327 purebred Pietrain sows bred to farrow purebred litters and data from 3413 Landrace $\times$ Yorkshire, 487 Duroc $\times$ Pietrain and 3191 commericial litters were udsed in this study. The data were collected form litters farrowed form January 1986 to December 1988 in Holiday Hills Stock and Breeding Farms, San Prero, Laguna. The crossbred sows and litters were better in most traits associated with sow productivity than their contemporary purebred sows and litters. The Duroc $\times$ Pietrain crossbred litters showed 16.67% improvement in litter size at weaning, 10.11% improvement in survival rate form birth to weaning and 16.21% more pigs per sow pre year than the averages of their parental breeds. The litters from the Landrace $\times$ Yorkshire crossbred sows sired by either Duroc or Duroc $\times$ Pietrain boars had 11.01% bigger litter size at birth, 20.74% increase in litter size at weaning and 22.86% more pigs weaned per sow per year than the averages of the four parental breeds. Very little improvement in most traits evaluated were observed form the Landrace $\times$ Yorkshire crossbred litters compared with their parental breeds. Year of birth of litter had litter influence on sow productivity. However, the reproductivity performance declined when sows farrowed in June up to September. The best Months of farrowing were found to be from January to April. The breed $\times$ year, breed $\times$ month and year $\times$ month had no significant effects on all traits evaluated.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제11권6호
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• pp.648-654
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• 1998

Twenty-four Javanese thin-tail ewes (11, 9, and 4 ewes giving birth to 1, 2, and 3 lambs, respectively) with similar body weight and age at breeding were used to study serum progesterone concentrations during pregnancy, milk production during lactation, and mammary gland indices at the end of lactation (3 months postpartum). The results of the experiment showed that averages serum progesterone concentrations during pregnancy in the ewes giving birth to twin and triplet lambs were higher (p < 0.01) than those giving birth to a single lamb. Ewes giving birth to 3 lambs had higher (p < 0.01) mammary dry fat-free tissue (DFFT) (by 31 and 34%), DNA concentration (by 25 and 16%) and RNA concentration (by 29 and 16%) at the end of lactation than those giving birth to 1 and 2 lambs. There was no difference in mammary collagen, protein and glycogen concentrations at the end of lactation among litter sizes. Ewes giving birth to 3 lambs had higher (p < 0.01) total mammary DNA content (by 64 and 61%) and RNA content (by 69 and 53%) at the end of lactation than those giving birth to 1 and 2 lambs. There was no difference in total mammary collagen, protein and glycogen contents at the end of lactation among litter sizes. Even though ewes with higher litter size had numerically higher milk production, there was no significant difference in milk production per 4 h among litter sizes. The results of the experiment indicated that ewes having higher litter size had greater mammary cell number and synthetic activities at the end of lactation. The results suggested that ewes with higher progesterone concentrations and better developed mammary glands during pregnancy could maintain higher cell number and activities throughout lactation.