Coefficient of Inbreeding

2012 ◽  
Author(s):  
Bimal P. Chaudhari
Keyword(s):  
Coefficient Of Inbreeding

scholarly journals Genetische Analyse der Population des Vorderwälder Rindes

2004 ◽  
Vol 47 (2) ◽  
pp. 141-153 ◽  
Author(s):  
G. Biedermann ◽  
B. Ott ◽  
K. Rübesam ◽  
F. Maus
Keyword(s):  
Genetic Analysis ◽  
Generation Interval ◽  
Genetische Analyse ◽  
Gene Contribution ◽  
The Mean ◽  
Coefficient Of Inbreeding

Abstract. Title of the paper: Genetic analysis of the population of Vorderwald cattle The actual population of Vorderwald cattle, comprising 5452 animals has been analysed concerning the gene contribution, the generation interval and the degree of relationship and inbreeding with regard of five generations of ancestors. About 84 % of the genes are originating from Vorderwald cattle. The genetic portions of other breeds have been contributed by Red Holsteins, Montbéliards and Ayrshires. The average generation interval parents–current animals is about 4.5 years. The mean relationship has been found out with 5.5 % within the bulls and 3.4 % within the cows. Accordingly the mean coefficient of inbreeding is higher within the bulls (2,7 %) than within the cows (2,4 %). Only 28.6 % of the bulls and 36.6 % of the cows are not inbred. With 0.9 % the increase of inbreeding in the last generation is of alarming proportions; that’s why a carefully directed program of mating has to be recommended.

SELECTION FOR SEED SET IN NONINBRED AND PARTLY INBRED POPULATIONS OF ALFALFA

1977 ◽  
Vol 57 (3) ◽  
pp. 873-881 ◽  
Author(s):  
R. MICHAUD ◽  
T. H. BUSBICE
Keyword(s):  
Medicago Sativa ◽  
Seed Set ◽  
Exponential Model ◽  
Seed Setting ◽  
Medicago Sativa L ◽  
Selection For ◽  
Inbred Populations ◽  
The Relationship ◽  
Advanced Generation ◽  
Coefficient Of Inbreeding

Alfalfa (Medicago sativa L.) is a highly heterozygous cross-pollinating species, and most breeding efforts have been conducted on noninbred populations. The purpose of this study was to determine whether greater breeding progress could be made by selecting within partly inbred populations rather than within noninbred ones. One hundred and twenty F1 (noninbred) and 120 S1 (partly inbred) plants that were issued from crossing and selfing four alfalfa clones were evaluated for self-fertility. The most self-fertile 10% of the plants from each family were selected in each population. The selected plants within each level of inbreeding were intercrossed to produce an advanced generation in which the effectiveness of the selection was evaluated. Selection increased both self- and cross-fertility in the advanced generation. Selection was more effective at the F1 level than at the S1 level. Fertility was reduced drastically by inbreeding. The average self-fertility of the S1’s was only about 7% of the cross-fertility of their parental clones. An exponential model was proposed to describe the relationship between seed setting and the coefficient of inbreeding in the developing zygote. This model explained 95% of the variation among 11 unselected populations having differing levels of inbreeding.

scholarly journals Effects of Selection and Linkage on Degree of Inbreeding

1966 ◽  
Vol 19 (2) ◽  
pp. 307 ◽  
Author(s):  
JL Gill ◽  
BA Clemmer
Keyword(s):  
Monte Carlo ◽  
Artificial Selection ◽  
Small Populations ◽  
Joint Effects ◽  
Two Factors ◽  
Coefficient Of Inbreeding

Monte Carlo computer techniques were employed to simulate inbreeding in small populations under regimes consisting of combinations of three degrees of linkage and three intensities of selection. Selection and linkage each significantly increased the rate of inbreeding in populations of a given size, although the effect of linkage was larger. Linkage contributions to bias in the coefficient of inbreeding may exceed those of selection in general, if one restricts comparisons to levels of the two factors that are similar with respect to the range of their possible values. Linkage also had a much larger effect than did selection on inflation of the variance of estimates of the coefficient of inbreeding. The joint effects of selection and linkage can have severe implications with respect to inbreeding in artificial selection programmes.

scholarly journals CIVIL UNREST AND THE CURRENT PROFILE OF CONSANGUINEOUS MARRIAGE IN KHYBER PAKHTUNKHWA PROVINCE, PAKISTAN

2013 ◽  
Vol 46 (5) ◽  
pp. 698-701 ◽  
Author(s):  
AFTAB ALAM STHANADAR ◽  
ALAN H. BITTLES ◽  
MUHAMMAD ZAHID
Keyword(s):  
Consanguineous Marriage ◽  
Current Profile ◽  
Khyber Pakhtunkhwa ◽  
Civil Unrest ◽  
Consanguineous Marriages ◽  
Current Prevalence ◽  
Khyber Pakhtunkhwa Province ◽  
Coefficient Of Inbreeding

SummaryInformation on the current prevalence and types of consanguineous marriages in Malakand District, Khyber Pakhtunkhwa Province (KPK), Pakistan, was collected from 1192 rural couples. Some 66.4% of marriages were between couples related as second cousins or closer (F≥0.0156), equivalent to a mean coefficient of inbreeding (α) of 0.0338. The data suggest that the prevalence of consanguineous unions in Malakand has been increasing during the last decade, in response to the high levels of violence across KPK.

scholarly journals Consanguinité, Isonymie et Age Précoce au Mariage dans les deux Provinces de Tétouan et M’diq-fnideq (Maroc)

2018 ◽  
Vol 14 (25) ◽  
pp. 63
Author(s):  
Mohamed Hajjaji ◽  
Abd Errazzak Khadmaoui ◽  
Abd El-Majid Soulaymani ◽  
Younes Azzouzi
Keyword(s):  
Marital Status ◽  
Significant Positive Correlation ◽  
Strong Association ◽  
Current Generation ◽  
Positive Correlation ◽  
Age At Marriage ◽  
Consanguineous Marriages ◽  
The Mean ◽  
Intergenerational Comparison ◽  
Coefficient Of Inbreeding

The purpose of this work is to contribute to the description of marital practices in Northern Morocco, to follow the evolution of these practices, and to determine the motives for marriages between relatives. Thus our results show a highly significant positive correlation between the age of the two spouses (r = 0.619, p <0.001), with the mean age of the mothers being 49.03 ± 6.56 years, while for the fathers it is 56,02 ± 6,16 years with a difference of 7 years between the two spouses in the current generation. For consanguineous marriages, we identified 51 relatives, namely a frequency of 25.4% for the generation of studied couples GCE, 13.3% for the generation of paternal grandparents GGPP, and 17.5% for the generation of maternal grandparents GGPM. The intergenerational comparison reveals a highly significant increase in the percentage of consanguinity, ranging from the generation of grandparents (15.4%) to that of the studied couples (25.4%), with a difference of 10% (p˂0.001). These results also show that there is a strong association between the prevalence of consanguineous marriages and the group of women under 19 years old (p = 0.002), whereas for husbands it is noted that There is no association between marital status and age at marriage. The coefficient of consanguinity estimated by isonymy is almost twice as large as the coefficient of inbreeding estimated by genealogy.

Microsatellite marker-based estimation of the genetic diversity of cattle in Chongqing

2018 ◽  
Author(s):  
Weiwei Ni ◽  
An Jiang ◽  
Jian Zhang ◽  
Guangxin E ◽  
Yongfu Huang
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
Microsatellite Marker ◽  
Weinberg Equilibrium ◽  
The Future ◽  
Hardy Weinberg Equilibrium ◽  
The Mean ◽  
Coefficient Of Inbreeding

Cattle are the main source of meat in Chongqing. This study investigated the genetic diversity of cattle native to Chongqing and 4 introduced breeds. A total of 96 individuals from 5 breeds were genotyped using six microsatellite markers. Five markers were highly polymorphic within the breed populations, and one marker had moderate levels of polymorphism. Heterozygosity ranged from 0.5379±0.0434 in Simmental to 0.6667±0.0559 in Charolais. The heterozygosity deficit was significant in all populations analyzed compared with the expected level of heterozygosity. In addition, two microsatellite markers (TGLA53 and OarFCB20) deviated from Hardy-Weinberg equilibrium across populations (except in cattle native to Chongqing). The mean number of alleles ranged from 6.00±2.37 in Angus to 7.17±2.14 in Droughtmaster across six markers. The coefficient of inbreeding ranged from 0.0017 in Simmental and Droughtmaster to 0.0367 in Angus. Pairwise difference analyses revealed that Simmental and Droughtmaster were the most differentiated (FST= 0.06861) from each other, whereas cattle native to Chongqing and Charolais were the least differentiated (FST= 0.00557). In summary, this study showed that cattle native to Chongqing and 4 introduced breeds were genetically well protected in Chongqing, and information from this study would be helpful for guiding hybridization and genetic improvements in the future.

Relationship between Coefficient of Inbreeding and Parasite Burden in Endangered Gazelles

2001 ◽  
Vol 15 (4) ◽  
pp. 1171-1174 ◽  
Author(s):  
Jorge Cassinello ◽  
Montserrat Gomendio ◽  
Eduardo R. S. Roldan
Keyword(s):  
Parasite Burden ◽  
Coefficient Of Inbreeding

Selection for economic characters in Australian Merino sheep.

1954 ◽  
Vol 5 (2) ◽  
pp. 305 ◽  
Author(s):  
FHW Morley
Keyword(s):  
Body Weight ◽  
Least Squares ◽  
Expected Value ◽  
Merino Sheep ◽  
Random Deviation ◽  
Selection For ◽  
Australian Merino ◽  
Coefficient Of Inbreeding ◽  
Staple Length

The effect of inbreeding and parent-offspring regressions for some economic characters of Merino sheep were estimated by a least-squares procedure. The model was: Yi = a + b1X1i + b2X2i + ei ,where Yi and X1i represent the phenotype and coefficient of inbreeding of the ith sheep, X2i the phenotype of the dam of that sheep, and ei the random deviation of Y, from its expected value. Increased coefficients of inbreeding were accompanied by highly significant decreases in greasy and clean fleece weights, body weight, and fold score. No significant association was observed between inbreeding and yield, staple length, crimps per inch, or birthcoat grading. Increased inbreeding was associated with decreased survival. Significant correlations between X1 and X2 were demonstrated for fleece weights, staple length, body weight, and crimps per inch. The implications of these correlations are discussed. The parent-offspring regressions were all highly significant. Estimates of heritability were high for all characters studied. The importance of these findings on the effectiveness of selection for flock improvement is considered.

MIGRATION AS A DETERMINANT OF MARRIAGE PATTERN: PRELIMINARY REPORT ON CONSANGUINITY AMONG AFGHANS

2005 ◽  
Vol 38 (3) ◽  
pp. 315-325 ◽  
Author(s):  
ABDUL WAHAB ◽  
MAHMUD AHMAD ◽  
SYED AKRAM SHAH
Keyword(s):  
Preliminary Report ◽  
Marriage Pattern ◽  
Cousin Marriage ◽  
Dominant Type ◽  
Resident Population ◽  
Refugee Population ◽  
Consanguineous Marriages ◽  
Significant Difference ◽  
The Mean ◽  
Coefficient Of Inbreeding

Two sample populations, one refugee and one resident, were studied. The frequencies of consanguineous marriages came out to be 49·8% and 55·4%, respectively, for the refugees and the residents. Caste endogamy was dominant both in the residents and the refugees. The mean coefficient of inbreeding was calculated to be 0·0303 for the refugee population and 0·0332 for the resident population samples. First cousin marriage was the dominant type of marriage in both samples; father’s brother’s daughter (FBD) marriage was more frequent among the refugees while mother’s brother’s daughter (MBD) marriage was more frequent among the residents. Education has no decreasing effect on the incidence of consanguineous marriages. A significant difference in the pattern of marriages in the refugees is observed after the Saur Revolution of 1979.

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