Analysis of population structure and genetic variability in Iranian buffaloes (Bubalus bubalis) using pedigree information

2016 ◽  
Vol 56 (7) ◽  
pp. 1130 ◽  
Author(s):  
Navid Ghavi Hossein-Zadeh

The objective of this study was to use pedigree analysis to evaluate the population structure, genetic variability and inbreeding in Iranian buffaloes. The analysis was based on the pedigree information of 42 285 buffaloes born from 549 sires and 6376 dams within 1697 herds. Pedigree information used in this study was collected during 1976 to 2012 by the Animal Breeding Centre of Iran. The CFC program was applied to calculate pedigree statistics and genetic structure analysis of the Iranian buffaloes. Also, the INBUPGF90 program was used for calculating regular inbreeding coefficients for individuals in the pedigree. The analysis of pedigree indicated that inbreeding coefficient ranged from 0% to 31% with an average of 3.42% and the trend of inbreeding was significantly positive over the years (P < 0.0001). Average coancestry was increased in recent years and overall generation interval was 6.62 years in Iranian buffaloes. Founder genome equivalent, founder equivalent, effective number of founders and effective number of non-founders were increased from 1976 to 2002, but their values decreased from 2002 onwards. A designed mating system to avoid inbreeding may be applied to this population of buffalo to maintain genetic diversity.

2015 ◽  
Vol 95 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Alicja Borowska ◽  
Tomasz Szwaczkowski

Borowska, A. and Szwaczkowski, T. 2015. Pedigree analysis of Polish warmblood horses participating in riding performance tests. Can. J. Anim. Sci. 95: 21–29. The aim of this study was to describe the population structure and genetic diversity in Polish warmblood horse population participating in the performance test. The reference population consisted of 596 stallions and 866 mares that participated in stationary performance tests conducted between 2002 and 2011 in Poland. The pedigree data contained 15 452 individuals. Completeness of pedigree information was assessed by two measures: percentage of animals with both parents known and discrete generation equivalent. Individual inbreeding coefficients, coancestry coefficient, individual increase in inbreeding, founder equivalent, founder genome equivalent, effective number of non-founders and genetic diversity loss were estimated to characterize the genetic diversity of the population. The average number of discrete generation equivalents reached 4.50 for observed stallions and 5.04 for mares, which shows good pedigree completeness. Pedigree analysis showed that 34% of the stallions and 44% of mares had inbreeding coefficients above zero. The average coancestry was 0.39% in the whole tested population. Average inbreeding rate of studied populations was very low (0.46%). The effective number of founders was 560. Generally, the inbreeding rate was low; genetic diversity was observed at a constant level for mares and only a small decrease was noticed for stallion. However, further studies are needed in this area.


2021 ◽  
Vol 8 ◽  
Author(s):  
Zhiying Wang ◽  
Bohan Zhou ◽  
Tao Zhang ◽  
Xiaochun Yan ◽  
Yongsheng Yu ◽  
...  

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&lt; Fi ≤ 6.25, 6.25&lt; 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.


Author(s):  
P. K. Mallick ◽  
I. Chauhan ◽  
S. M.K. Thirumaran ◽  
R. Pourouchttamane ◽  
Arun Kumar

Background: The genetic variability in a population is the raw material for selection, because the estimation of genetic parameters depends on the variability present within the population. The pedigree analysis is a method to assess population genetic variability. An increase in the level of inbreeding disturbs the production performance of the animals. Hence, it is essential to assess the effect of inbreeding on production performance of the animals at regular intervals. The present study was conducted on data of Bharat Merino (BM) sheep with twin objectives of evaluating the population structure by pedigree analysis and possible effect of inbreeding on lamb growth and heritability estimates. Methods: The study was conducted on data consisting of a total of 9688 pedigree records of BM sheep born from 1975 to 2018 (43 years), out of which 9050 formed population reference (with both the parents known). ENDOG ver 4.8 program was used to generate different measures of genetic diversity. General Linear Model of SPSS 25.0 was used to ascertain the effect of inbreeding (Fi) or change in inbreeding (ÄFi) on the lamb live weights. Using animal model with software WOMBAT, single trait linear mixed model analyses were performed. The heritability estimates and breeding values were obtained by including or excluding the inbreeding coefficient in the model to observe how the estimates of heritability varied with inclusion or exclusion of the inbreeding coefficient. Result: Effective number of founders (fe) was 56, constituting 11.39% founders in the population reference, while the effective number of ancestors (fa) was 43.The genetic contribution of the 15 most influent ancestors explained 50% of the genetic variability in the dataset. The ratio fe/fa, representing the effect of population bottleneck, was 1.302. The average inbreeding coefficients for the whole pedigree was 2.36%, while it was 3.84% for inbred animals. It was found that the inbreeding coefficient (Fi) increased with the addition of each generation to the pedigree. The average relatedness coefficient was 4.53% between members of the population.The effect of individual inbreeding (Fi) or the change in inbreeding (DFi) was not significant on the lamb live weights, except the effect of individual inbreeding (Fi) on three-month body weight and average daily gain (0-3month) and of change in inbreeding (DFi) on three-month body weight. From the analysis of the pedigree data of Bharat Merino sheep, it was found that the most of the measures of genetic diversity were within acceptable limits and the pedigree data was reasonably well maintained. When inbreeding was accounted for in the model, there were reductions in h2 estimates as well as the estimates of breeding values for both 3WT and ADG1 and consequently there were changes in ranking of animals for both 3WT and ADG1.


2018 ◽  
Vol 53 (1) ◽  
pp. 74-79 ◽  
Author(s):  
Ligia Cavani ◽  
Rafael Medeiros de Oliveira Silva ◽  
Luis Orlando Duitama Carreño ◽  
Rafael Keith Ono ◽  
Tássia Souza Bertipaglia ◽  
...  

Abstract: The objective of this work was to evaluate the genetic diversity of Brahman cattle in Brazil with pedigree analysis. Genealogical records of a subpopulation were used considering all pedigree information (Pt) and the pedigree information divided into two periods (P1, from 1994 to 2004; and P2, from 2005 to 2012) or according to the raising system (Ppt, animals on pasture; or Pst, on stable). Estimates were obtained for average inbreeding coefficients, generation intervals (GI), number of equivalent known generation (CGE), number of founders (Nf), effective number of founders (fe), effective number of ancestors (fa), and founder genome equivalents (fg). The average inbreeding coefficients were 11.97, 7.79, 11.95, 11.74, and 11.31% for Pt, P1, P2, Ppt, and Pst, respectively. Average GI was 4.4 years, whereas CGE was 3.18. The fe values were similar to those of fa, which were greater than those of fg. The fe/fa and fg/fe ratios were close to 1, which indicates no genetic bottleneck and small losses by genetic drift. The genetic diversity in the Brazilian population of Brahman breed is not significantly reduced.


2010 ◽  
Vol 39 (12) ◽  
pp. 2640-2645 ◽  
Author(s):  
João Cruz Reis Filho ◽  
Paulo Sávio Lopes ◽  
Rui da Silva Verneque ◽  
Robledo de Almeida Torres ◽  
Roberto Luiz Teodoro ◽  
...  

The objective of the present study was to evaluate the genetic structure of Gyr cattle selected for milk production. Files of pedigree and production were composed of 27,610 animals. The ENDOG program was used for the calculation of individual inbreeding coefficient (F) and coefficient of average relatedness (AR), effective number of animals(Ne), effective number of founders (f e) and ancestors (f a), and generation interval (GI). Individual inbreeding coefficients and average relatedness in the population were 2.82% and 2.10%, respectively. It was observed a reduction in the effective number of animals, especially after publication of the results of the first progeny test. The estimated effective number of founders was 146 and 75 for the ancestrals. Out of those, only 28 ancestors accounted for the origin of 50% of the population genes. The average generation interval was 8.41 years and it was longer for males than for females. For maintaining genetic variability in future generations, it should be invested mating strategies that reduce inbreeding and which do not use massively only some high breeding value sires.


2011 ◽  
Vol 54 (1) ◽  
pp. 1-9
Author(s):  
L. Vostrý ◽  
Z. Čapková ◽  
J. Přibyl ◽  
B. Hofmanová ◽  
H. Vostrá Vydrová ◽  
...  

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


2010 ◽  
Vol 45 (10) ◽  
pp. 1109-1116 ◽  
Author(s):  
Carlos Henrique Mendes Malhado ◽  
Paulo Luiz Souza Carneiro ◽  
Ana Claudia Mendes Malhado ◽  
Raimundo Martins Filho ◽  
Riccardo Bozzi ◽  
...  

The objective of this work was to evaluate the population structure and the genetic and phenotypic progress of Nelore cattle in Northern Brazil. Pedigree information concerning animals born between 1942 and 2006 were analyzed. Population structure was performed using the Endog program. Out of the 140,628 animals studied, 67.7, 14.52 and 3.18% had complete pedigree record of the first, second and third parental generation, respectively. Inbreeding and average relatedness coefficients were low: 0.2 and 0.13%, respectively. However, these parameters may have been underestimated, since information on pedigree was incomplete. The effective number of founders was 370 and the genetic contribution of 10, 50 and 448 most influent ancestors explained 13.2, 28 and 50% of the genetic variability in the population, respectively. The genetic variability for growth traits and population structure demonstrates high probability of increasing productivity through selective breeding. Moreover, management strategies to reduce the currently observed age at first calving and generation intervals are important for Nelore cattle genetic improvement.


2021 ◽  
Vol 73 (1) ◽  
pp. 231-238
Author(s):  
N.L. Ribeiro ◽  
G.R. Medeiros ◽  
G.V. Nascimento ◽  
J.K.G. Arandas ◽  
M.N. Ribeiro

ABSTRACT The objective of this research was to study the population structure of the Cattle Conservation Nucleos Curraleiro Pé Duro of the Instituto Nacional do Semiárido (NCP_INSA) based on pedigree data. Genealogical information from 338 animals registered in the period from 1991 to 2019 was used. The number of founding animals (Nf), the effective number of founders (fe), effective number of ancestors (fa), inbreeding coefficient (F), and average relatedness coefficient (AR), in addition to Fis, Fit and Fst were estimated. It was possible to identify ancestors up to the third generation, with an increase in information over the generations. Of the total pedigree information evaluated, 90.53% had the identification of the father and mother. The effective size of the population was smaller than those proposed by FAO, suggesting the need to redefine the herd management and genetic management plan strategies, promoting gene flow and breed expansion.


2018 ◽  
Vol 63 (No. 6) ◽  
pp. 237-246 ◽  
Author(s):  
E. Somogyvári ◽  
J. Posta ◽  
S. Mihók

The population genetic evaluation of the Hungarian Hucul horse population was performed based on pedigree records. Herd book data of registered Hucul horses available up to 2016 were analysed using ENDOG (Gutierrez and Goyache 2005) and POPREP (Groeneveld et al. 2009) on the whole population (WP) as well as on the reference stock (RS) (breeding stock registered in 2016). Inbreeding coefficients were 5.57% (WP) and 7.18% (RS). Average relatedness was 10.39% in WP and higher in RS (12.67%). Effective population size was 52.32. Generation interval was 13.01 years for WP and 10.99 years for RS. The values for equivalent complete generations were 6.07 and 8.75, for the maximum number of generations 14.11 and 19.16, and for the number of full generations traced 3.77 and 5.50 for WP and RS, respectively. The effective number of founders (f<sub>e</sub>) was 23 both for WP and RS. The effective number of ancestors (f<sub>a</sub>) was 20 in WP and lower in RS (16). The f<sub>a</sub>/f<sub>e</sub> ratio was 0.869 in WP and 0.696 in RS. Founder genome equivalent (f<sub>g</sub>) was 9.618 in WP and 5.790 in RS. The f<sub>g</sub>/f<sub>e</sub> ratio was 0.481 in WP and 0.361 in RS. The study revealed that both the inbreeding coefficient and the average relatedness were high. The above mentioned ratios indicated loss of genetic diversity in the Hungarian Hucul population.


1995 ◽  
Vol 85 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Philippe Borsa ◽  
D. Pierre Gingerich

AbstractSeven presumed Mendelian enzyme loci (Est-2, Est-3, Gpi, Idh-l, Idh-2, Mdh-2 and Mpi) were characterized and tested for polymorphism in coffee berry borers, Hypothenemus hampei (Ferrari), sampled in Côte d′Ivoire, Mexico and New Caledonia. The average genetic diversity was H = 0.080. Two loci, Mdh-2 and Mpi were polymorphic, and thus usable as genetic markers. The population structure of H. hampei was analysed using Weir & Cockerham's estimators of Wright's F-statistics. A high degree of inbreeding (f = 0.298) characterized the elementary geographic sampling unit, the coffee field. The estimate of gene flow between fields within a country was Nm = 10.6 and that between countries was Nm = 2. The population genetic structure in H. hampei could be related to its known population biological features and history.


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