Genetic inbreeding depression load for morphological traits and defects in the Pura Raza Española horse

Abstract Background Inbreeding is caused by mating between related individuals and is associated with reduced fitness and performance (inbreeding depression). Several studies have detected heterogeneity in inbreeding depression among founder individuals. Recently, a procedure was developed to predict hidden inbreeding depression load that is associated with founders using the Mendelian sampling of non-founders. The objectives of this study were to: (1) analyse the population structure and general inbreeding, and (2) test this recent approach for predicting hidden inbreeding depression load for four morphological traits and two morphology defects in the Pura Raza Española (PRE) horse breed. Results The regression coefficients that were calculated between trait performances and inbreeding coefficients demonstrated the existence of inbreeding depression. In total, 58,772,533 partial inbreeding coefficients (Fij) were estimated for the whole PRE population (328,706 horses). We selected the descendants of horses with a Fij ≥ 6.25% that contributed to at least four offspring and for which morphological traits were measured for the subsequent analysis of inbreeding depression load (639 horses). A pedigree was generated with the last five generations (5026 animals) used as the reference population (average inbreeding coefficient of 8.39% and average relatedness coefficient of 10.76%). Heritability estimates ranged from 0.08 (cresty neck) to 0.80 (height at withers), whereas inbreeding depression load ratios ranged from 0.01 (knock knee) to 0.40 (length of shoulder), for an inbreeding coefficient of 10%. Most of the correlations between additive and inbreeding depression load genetic values and correlations between inbreeding depression load genetic values for the different traits were positive or near 0. Conclusions Although the average inbreeding depression loads presented negative values, a certain percentage of the animals showed neutral or even positive values. Thus, high levels of inbreeding do not always lead to a decrease in mean phenotypic value or an increase in morphological defects. Hence, individual inbreeding depression loads could be used as a tool to select the most appropriate breeding animals. The possibility of selecting horses that have a high genetic value and are more resistant to the deleterious effects of inbreeding should help improve selection outcomes.

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Effects of inbreeding on number of piglets born total, born alive and weaned in Austrian Large White and Landrace pigs

Archives Animal Breeding ◽

10.5194/aab-52-51-2009 ◽

2009 ◽

Vol 52 (1) ◽

pp. 51-64 ◽

Cited By ~ 2

Author(s):

A. Köck ◽

B. Fürst-Waltl ◽

R. Baumung

Keyword(s):

Inbreeding Depression ◽

Reproductive Performance ◽

Regression Models ◽

Inbreeding Coefficient ◽

Significant Positive Effect ◽

Weaned Piglets ◽

Large White ◽

Inbreeding Coefficients ◽

Negative Effect ◽

Positive Effect

Abstract. In this study records of 58 925 litters of Austrian Large White and 17 846 litters of Austrian Landrace pigs were analysed. Regression models were used to determine the effects of litter, dam and sire inbreeding on total number of born, born alive and weaned piglets in Large White and Landrace. In both populations, litter and dam inbreeding showed a negative effect on all traits. Sire inbreeding had no effect in Large White, whereas a significant positive effect was observed in Landrace. On average, inbred sires with an inbreeding coefficient of 10 % had 0.45 more piglets born total and 0.43 more piglets born alive in comparison to non-inbred sires. In a further analysis the total inbreeding coefficients of the animals were divided into two parts: »new« and »old« inbreeding. »New« inbreeding was defined as the period of the first five generations. It was shown that the observed inbreeding effects were not only caused by recent inbreeding. Reproductive performance was also affected by »old« inbreeding. Finally partial inbreeding coefficients of four important ancestors in each population were calculated to investigate if inbreeding effects are similar among these ancestors. The results revealed a varation of inbreeding effects among the four ancestors. Alleles contibuting to inbreeding depression were descendent from specific ancestors.

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Inbreeding effects on some reproductive traits in Markhoz goats

Animal Production Science ◽

10.1071/an17043 ◽

2018 ◽

Vol 58 (12) ◽

pp. 2178 ◽

Cited By ~ 3

Author(s):

P. Mahmoudi ◽

A. Rashidi ◽

M. Razmkabir

Keyword(s):

Litter Size ◽

Inbreeding Depression ◽

Reproductive Traits ◽

Information Criterion ◽

Inbreeding Coefficient ◽

Regression Coefficients ◽

Litter Weight ◽

Inbreeding Coefficients ◽

Poisson Models ◽

The Individual

The objective of this study was to estimate the inbreeding coefficient and its effects on reproductive traits in Markhoz goats. The pedigree file included 5351 kids produced by 234 bucks and 1470 does. Average inbreeding coefficient for the whole population was 2.68%, and the minimum and maximum inbreeding coefficients were 0.05% and 31.25%, respectively. Average coefficient of inbreeding for inbred population was 5.17% and the number of inbred animals in the population was 2777. For investigating effects of inbreeding coefficient on reproductive traits, 3443 records were available for litter size at birth (LSB), litter size at weaning (LSW), total litter weight at birth (TLWB) and mean of litter weight at birth (MLWB). Furthermore, available records for total litter weight at weaning (TLWW) and mean of litter weight at weaning (MLWW) were 2918. Inbreeding depression was estimated as the linear regression of performance on the individual inbreeding coefficient of kids and dams using the most appropriate animal model based on Akaike’s information criterion. Furthermore, inbreeding depressions for LSB and LSW were estimated using threshold and Poisson models. Regression coefficients of LSB, LSW, TLWB, TLWW, MLWB and MLWW on inbreeding coefficient of kids were –0.035, –0.019, –0.077 kg, –0.782 kg, –0.009 kg and –0.332 kg, respectively. Furthermore, regression coefficients of LSB, LSW, TLWB, TLWW, MLWB and MLWW on inbreeding coefficient of dams were 0.064, –0.013, 0.241 kg, 0.638 kg, 0.028 kg and –1.783 kg, respectively. The obtained results from this study showed that inbreeding depression is controlled by an appropriate mating system policy.

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Assessing Genetic Diversity and Estimating the Inbreeding Effect on Economic Traits of Inner Mongolia White Cashmere Goats Through Pedigree Analysis

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.665872 ◽

2021 ◽

Vol 8 ◽

Author(s):

Zhiying Wang ◽

Bohan Zhou ◽

Tao Zhang ◽

Xiaochun Yan ◽

Yongsheng Yu ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Inbreeding Depression ◽

Inner Mongolia ◽

Inbreeding Coefficient ◽

Production Performance ◽

Pedigree Information ◽

Economic Traits ◽

Inbreeding Coefficients ◽

Cashmere Goats

Objective: The purpose of this study was to discover the population structure and genetic diversity of Inner Mongolia White Cashmere goats (IMCGs) and demonstrate the effect of inbreeding on the live body weight (LBW), cashmere yield (CY), fiber length (FL), and fiber diameter (FD) of IMCGs.Materials and Methods: All data were collected from pedigree information and production performance records of IMCGs from 1983 to 2019. The population structure and genetic diversity were analyzed by Endog 4.8 software. Inbreeding coefficients were obtained by the pedigree package in R. Then, a linear regression model was used to analyze how inbreeding influences economic traits in IMCGs. Four levels of inbreeding coefficients (Fi) were classified in this study, including Fi = 0, 0< Fi ≤ 6.25, 6.25< Fi ≤ 12.5 and Fi≥12.5. Variance analysis was performed to determine whether inbreeding levels had a significant effect on economic traits in IMCGs.Results: The proportions of rams and dams in IMCGs for breeding were relatively small, with values of 0.8 and 20.5%, respectively. The proportion of inbred animals in the entire population was high, with values up to 68.6%; however, the average inbreeding coefficient and relatedness coefficient were 4.50 and 8.48%, respectively. To date, the population has experienced 12 generations. The average generation interval obtained in the present study was 4.11 ± 0.01 years. The ram-to-son pathway was lowest (3.97 years), and the ewe-to-daughter pathway was highest (4.24 years). It was discovered that the LBW, CY, and FL increased by 3.88 kg, 208.7 g, and 1.151 cm, respectively, with every 1% increase in the inbreeding coefficient, and the FD decreased by 0.819 μm with every 1% increase in the inbreeding coefficient. Additionally, multiple comparison analysis indicated that when the inbreeding coefficient was higher than 6.25%, the LBW showed an obvious decreasing trend. The threshold value of inbreeding depression in the CY is 12.5%. However, inbreeding depression has not been observed in the FL and FD.Conclusion: Pedigree completeness needs to be further strengthened. The degree of inbreeding in this flock should be properly controlled when designing breeding programs.

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Rank-invariant estimation of inbreeding coefficients

Heredity ◽

10.1038/s41437-021-00471-4 ◽

2021 ◽

Author(s):

Qian S. Zhang ◽

Jérôme Goudet ◽

Bruce S. Weir

Keyword(s):

Genetic Data ◽

Reference Population ◽

Inbreeding Coefficient ◽

Allele Sharing ◽

Ancestral Allele ◽

1000 Genomes ◽

Inbreeding Coefficients ◽

Identical By Descent ◽

Invariant Estimation ◽

The Individual

AbstractThe two alleles an individual carries at a locus are identical by descent (ibd) if they have descended from a single ancestral allele in a reference population, and the probability of such identity is the inbreeding coefficient of the individual. Inbreeding coefficients can be predicted from pedigrees with founders constituting the reference population, but estimation from genetic data is not possible without data from the reference population. Most inbreeding estimators that make explicit use of sample allele frequencies as estimates of allele probabilities in the reference population are confounded by average kinships with other individuals. This means that the ranking of those estimates depends on the scope of the study sample and we show the variation in rankings for common estimators applied to different subdivisions of 1000 Genomes data. Allele-sharing estimators of within-population inbreeding relative to average kinship in a study sample, however, do have invariant rankings across all studies including those individuals. They are unbiased with a large number of SNPs. We discuss how allele sharing estimates are the relevant quantities for a range of empirical applications.

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Population Structure Analysis of the Border Collie Dog Breed in Hungary

Animals ◽

10.3390/ani9050250 ◽

2019 ◽

Vol 9 (5) ◽

pp. 250 ◽

Cited By ~ 5

Author(s):

Virág Ács ◽

Árpád Bokor ◽

István Nagy

Keyword(s):

Genetic Diversity ◽

Reference Population ◽

Inbreeding Coefficient ◽

Pedigree Data ◽

Effective Population ◽

Inbreeding Coefficients ◽

Population Structure Analysis ◽

Dog Breed ◽

Fixation Indices ◽

Mixed Line

Pedigree data of the Border Collie dog breed were collected in Hungary to examine genetic diversity within the breed and its different lines. The database was based on available herd books dating from the development of the breed (in the late 1800s) to the present day. The constructed pedigree file consisted of 13,339 individuals, of which 1566 dogs (born between 2010 and 2016) composed the alive reference population which was active from breeding perspective. The breed is subdivided by phenotype, showing a thicker coat, harmonic movement, a wide skull, and heavier bones for the show type, and a thinner or sometimes short coat and smaller body for the working line, while the mixed line is quite heterogeneous (a combination of the above). Thus, the reference population was dissected according to the existing lines. The number of founders was 894, but eight individuals were responsible for contributing 50% of the genetic variability. The reference population had a pedigree completeness of 99.6% up to 15 generations and an inbreeding coefficient of 9.86%. Due to the changing breed standards and the requirements of the potential buyers, the effective population size substantially decreased between 2010 and 2016. Generation intervals varied between 4.09 and 4.71 years, where the sire paths were longer due to the later initial age of breeding in males compared to females. Genetic differences among the existing lines calculated by fixation indices are not significant; nonetheless ancestral inbreeding coefficients are able to show contrasts.

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Bedeutung der Inzucht bei Tauernschecken-Ziegen

Archives Animal Breeding ◽

10.5194/aab-46-455-2003 ◽

2003 ◽

Vol 46 (5) ◽

pp. 455-469

Author(s):

R. M. Wokac

Keyword(s):

Traditional Knowledge ◽

Inbreeding Depression ◽

Conservation Biology ◽

Rare Species ◽

Inbreeding Coefficient ◽

Inbreeding Coefficients ◽

Breeding Management ◽

Rate Of Increase ◽

Low Rate

Abstract. Title of the paper: On the importance of inbreeding at Tauernschecken goats This analysis of Tauernschecken goats, an Austrian alpine rare breed, wants to find out if there is any inbreeding depression. Therefore 1749 animals born at 1962 to 2002 were judged for their exterieur, duration of live, fecundity, viability and weight of offspring; besides their inbreeding coefficient was calculated. The average inbreeding coefficient ranges from 5 to 6 %. The degree of inbreeding is in accordance with the lowest third of inbreeding of other rare species. Over the last ten years a low rate of increase in inbreeding of 0,19 % per generation can be observed. There is no correlation of one of these judged criterions of productivity and the inbreeding coefficient, which allows the conclusion that there is no inbreeding depression in Tauernschecken goats. Conservation biology offers some interpretations. The traditional entire breeding management should not be given up for overestimating some inbreeding coefficients. Preservation of endangered rare breeds as cultural ressources means also to preserve the traditional knowledge of the complexity of breeding criterions.

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Assessment of Inbreeding Depression and Inbreeding Trend of Production Traits in Iraqi Holstein Cows

Asian Journal of Biotechnology and Bioresource Technology ◽

10.9734/ajb2t/2019/v5i430064 ◽

2019 ◽

pp. 1-9

Author(s):

Farzad Moradpour ◽

Hana Hamidi

Keyword(s):

Inbreeding Depression ◽

Milk Fat ◽

Fixed Effects ◽

Continuous Variable ◽

Inbreeding Coefficient ◽

Holstein Cows ◽

Production Traits ◽

Inbreeding Coefficients ◽

Identical By Descent ◽

Related Individuals

Inbreeding is defined as the probability that two alleles at any locus are identical by descent and occur when related individuals are mated to each other. A total of 123427, 115810 and 88361 records of 412-d yields of milk, fat and protein of Iraqi Holstein cows were collected from 1995 to 2010 in 838 herds used to estimation the inbreeding depression and inbreeding trend. Pedigree records of Iraqi Holstein cow were used to assessment inbreeding coefficients and these coefficients ranged from 0 to 42%. Animal model was used to estimation inbreeding depression on traits. Fixed effects included in statistical model were herd – year, age at calving and inbreeding coefficient as continuous and discrete variable. When considering inbreeding as continuous variable in model, the inbreeding depression for 412-d yields of milk, fat and protein were -28.19, -0.98 and -0.88 kg per 1% increase in inbreeding in Iraqi Holsteins, respectively. In this group of animal that inbreeding coefficient was between 0 < F ≤ 5.34 inbreeding was not caused reduction in production traits. However, in group of animal that inbreeding coefficient was greater than 5.34, and inbreeding depression in production traits was observed. The result of this study confirms of inbreeding depression in Iraqi Holstein cows.

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The value of genomic relationship matrices to estimate levels of inbreeding

Genetics Selection Evolution ◽

10.1186/s12711-021-00635-0 ◽

2021 ◽

Vol 53 (1) ◽

Author(s):

Beatriz Villanueva ◽

Almudena Fernández ◽

María Saura ◽

Armando Caballero ◽

Jesús Fernández ◽

...

Keyword(s):

Inbreeding Depression ◽

Inbreeding Coefficient ◽

Relationship Matrix ◽

Base Population ◽

Genomic Relationship ◽

Nucleotide Polymorphism ◽

Single Nucleotide ◽

Inbreeding Coefficients ◽

Locus Model ◽

Genomic Inbreeding

Abstract Background Genomic relationship matrices are used to obtain genomic inbreeding coefficients. However, there are several methodologies to compute these matrices and there is still an unresolved debate on which one provides the best estimate of inbreeding. In this study, we investigated measures of inbreeding obtained from five genomic matrices, including the Nejati-Javaremi allelic relationship matrix (FNEJ), the Li and Horvitz matrix based on excess of homozygosity (FL&H), and the VanRaden (methods 1, FVR1, and 2, FVR2) and Yang (FYAN) genomic relationship matrices. We derived expectations for each inbreeding coefficient, assuming a single locus model, and used these expectations to explain the patterns of the coefficients that were computed from thousands of single nucleotide polymorphism genotypes in a population of Iberian pigs. Results Except for FNEJ, the evaluated measures of inbreeding do not match with the original definitions of inbreeding coefficient of Wright (correlation) or Malécot (probability). When inbreeding coefficients are interpreted as indicators of variability (heterozygosity) that was gained or lost relative to a base population, both FNEJ and FL&H led to sensible results but this was not the case for FVR1, FVR2 and FYAN. When variability has increased relative to the base, FVR1, FVR2 and FYAN can indicate that it decreased. In fact, based on FYAN, variability is not expected to increase. When variability has decreased, FVR1 and FVR2 can indicate that it has increased. Finally, these three coefficients can indicate that more variability than that present in the base population can be lost, which is also unreasonable. The patterns for these coefficients observed in the pig population were very different, following the derived expectations. As a consequence, the rate of inbreeding depression estimated based on these inbreeding coefficients differed not only in magnitude but also in sign. Conclusions Genomic inbreeding coefficients obtained from the diagonal elements of genomic matrices can lead to inconsistent results in terms of gain and loss of genetic variability and inbreeding depression estimates, and thus to misleading interpretations. Although these matrices have proven to be very efficient in increasing the accuracy of genomic predictions, they do not always provide a useful measure of inbreeding.

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Effect of inbreeding and individual increase in inbreeding on growth in Nilagiri and Sandyno breeds of sheep

Animal Genetic Resources/Ressources génétiques animales/Recursos genéticos animales ◽

10.1017/s2078633615000338 ◽

2016 ◽

Vol 58 ◽

pp. 63-71 ◽

Cited By ~ 1

Author(s):

R. Venkataramanan ◽

A. Subramanian ◽

S.N. Sivaselvam ◽

T. Sivakumar ◽

C. Sreekumar ◽

...

Keyword(s):

Growth Traits ◽

Inbreeding Coefficient ◽

Pedigree Information ◽

Research Station ◽

Sheep Breeding ◽

Inbreeding Coefficients ◽

Equivalent Number ◽

Breeding Research ◽

Percent Increase ◽

Two Populations

SummaryIndividual increase in inbreeding coefficients (ΔFi) has been recommended as an alternate measure of inbreeding. It can account for the differences in pedigree knowledge of individual animals and avoids overestimation due to increased number of known generations. The effect of inbreeding (F) and equivalent inbreeding (EF) calculated fromΔFi, on growth traits were studied in Nilagiri and Sandyno flocks of sheep. The study was based on data maintained at the Sheep Breeding Research Station, Sandynallah. The pedigree information and equivalent number of generations were less in Sandyno compared with Nilagiri sheep. The average F and EF for the Nilagiri population were 2.17 and 2.44, respectively and the corresponding values for Sandyno sheep were 0.83 and 0.84, respectively. The trend of inbreeding over years in both the populations indicated that EF was higher during earlier generations when pedigree information was shallow. Among the significant effects of inbreeding, the depression in growth per 1 percent increase in inbreeding ranged from 0.04 kg in weaning weight to 0.10 kg in yearling weight. In general, more traits were affected by inbreeding in Nilagiri sheep, in which greater regression of growth traits was noticed with F compared with EF. Higher values of EF than F in earlier generations in both the populations indicate that EF avoided the potential overestimation of inbreeding coefficient during recent generations. In the Sandyno population, the magnitude of depression noticed among growth traits with significant effects of inbreeding was higher. The differences in response to F and EF noticed in the two populations and possible causes for the trait wise differences in response to F and EF are appropriately discussed.

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Population structure of Czech cold-blooded breeds of horses

Archives Animal Breeding ◽

10.5194/aab-54-1-2011 ◽

2011 ◽

Vol 54 (1) ◽

pp. 1-9

Author(s):

L. Vostrý ◽

Z. Čapková ◽

J. Přibyl ◽

B. Hofmanová ◽

H. Vostrá Vydrová ◽

...

Keyword(s):

Population Structure ◽

Genetic Variability ◽

Population Size ◽

Effective Population Size ◽

Inbreeding Coefficient ◽

Effective Population ◽

The Czech Republic ◽

Generation Interval ◽

Average Value ◽

Inbreeding Coefficients

Abstract. In order to estimate effective population size, generation interval and the development of inbreeding coefficients (Fx) in three original breeds of cold-blooded horses kept in the Czech Republic: Silesian Noriker (SN), Noriker (N) and Czech-Moravian Belgian horse (CMB) all animals of the particular breeds born from 1990 to 2007 were analysed. The average values of generation interval between parents and their offspring were: 8.53 in SN, 8.88 in N and 8.56 in CMB. Average values of effective population size were estimated to be: 86.3 in SN, 162.3 in N and 104.4 in CMB. The average values of inbreeding coefficient were 3.13 % in SN stallions and 3.39 % in SN mares, in the N breed 1.76 % and 1.26 % and in the CMB breed 3.84 % and 3.26 % respectively. Overall averages of Fx were: 3.23 %, 1.51 % and 3.55 % for the breeds SN, N and CMB. The average value of inbreeding coefficient Fx increased by 1.22 % in SN, by 0.35 % in N and by 1.01 % in CMB, respectively. This may lead to a reduction in genetic variability. Reduction in genetic variability could be either controlled in cooperation with corresponding populations of cold-blooded breeds in other European countries or controlled by number of sires used in population

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