Analysis of founders and performance test effects on an autochthonous horse population through pedigree analysis: structure, genetic variability and inbreeding.
Abstract: The Maremmano is an autochthonous Italian horse breed, which probably descended from the native horses of the Etruscans (VI century B.C.); the Studbook was acknowledged in 1980, and it includes 12 368 horses born from that year up to 2015. The aim of this study was to evaluate the effect of the selection program on the genetic variability of the Maremmano population; the analysis was performed using both the 'Endog v 4.8' program available at http://webs.ucm.es/info/prodanim/html/JP_Web.htm and in-house software on official pedigree data. Four Reference Populations were considered, and the most important one was the population of the 12 368 Maremmano horses officially registered in the National Studbook. The pedigree completeness of this population was very good because it was more than 90% at the third parental generation and more than 70% at the fifth generation; the pedigree traced back to a maximum of 10.50 generations with an average of 3.30 complete generations and 5.70 equivalent complete generations. The average generation interval was 10.65±4.72 years, with stallions used for longer periods than mares. The intervals ranged from 10.15±4.45 (mother-daughter) to 10.99±4.93 (father-daughter). The effective number of founders (f e) was 74 and the effective number of ancestors (f a) was 30 so that the ratio f e/f a was 2.47. The founder genome equivalents (f g) was 13.72 with a ratio f g/f e equal to 0.18. The mean of the genetic conservation index was 5.55±3.37, and it ranged from 0.81 to 21.32. The average inbreeding coefficient was 2.94%, with an increase of 0.1%/year, and the average relatedness coefficient was 5.52%. The effective population size (N e) computed by an individual increase in inbreeding was 68.1±13.00; the N e on equivalent generations was 42.00, and this value slightly increased to 42.20 when computed by Log regression on equivalent generations. The analysis confirmed the presence of seven traditional male lines. The percentage of Thoroughbred blood in the foals born in 2015 was 20.30% and has increased 0.21%/year since 1980; in particular, it increased more than twice (0.51%/year) until 1993 and afterwards slightly fluctuated. The pedigree analysis confirmed the completeness of genealogical information and the traditional importance that breeders gave to the male lines; although the genetic diversity of Maremmano seemed to be not endangered by the selection program, some effects on the population structure were found and a more scientific approach to genetic conservation should be incorporated in the selection plans.
Publication Date: 2018-05-29 PubMed ID: 29807556DOI: 10.1017/S1751731118001180Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research paper examines the impact of selection programs on the genetic diversity of the Maremmano, a native Italian horse breed. It utilizes the ‘Endog v 4.8’ program and proprietary software to analyze official pedigree data of the horses registered in the National Studbook. It identifies a need for a more scientific approach to genetic conservation in selection plans.
Research Methodology
- This study’s primary focus is the Maremmano, a horse breed native to Italy, believed to have descended from the horses of the Etruscans.
- The researchers used both an online program, ‘Endog v 4.8’, and proprietary software to analyze pedigree data from the National Studbook. This studbook contained records of 12,368 Maremmano horses birthed from 1980 to 2015.
- Four reference populations were considered in the study but the most relevant one was the population of the Maremmano horses registered in the National Studbook.
Results & Findings
- The study reveals that the pedigree completion of this population was high, with greater than 90% completeness at the third parental generation and more than 70% at the fifth generation.
- The pedigree traced back to a maximum of 10.5 generations with an average of 3.3 complete generations and 5.7 equivalent complete generations.
- The average generation interval was 10.65±4.72 years, with stallions used for a longer period than mares.
- The effective number of founders (f e) was determined to be 74, and the effective number of ancestors (f a) was 30, yielding a f e/f a ratio of 2.47. The founder genome equivalents (f g) stood at 13.72, with a f g/f e ratio equaling 0.18.
- The mean genetic conservation index was calculated to be 5.55±3.37, with a range from 0.81 to 21.32.
- The average inbreeding coefficient was 2.94%, with a year-on-year growth rate of 0.1%. The average relatedness coefficient was measured at 5.52%.
Conclusion
- The thoroughbred blood percentage in the 2015 foals increased by 20.30%, with an annual increase rate of 0.21% since 1980.
- The research corroborated the complete genealogical information and the emphasis breeders place on male lines but suggested some effects on the population structure.
- The authors concluded that while the Maremmano’s genetic diversity doesn’t seem threatened by the selection program, there is a need for a more scientific approach to genetic conservation in selection plans.
Cite This Article
APA
Giontella A, Pieramati C, Silvestrelli M, Sarti FM.
(2018).
Analysis of founders and performance test effects on an autochthonous horse population through pedigree analysis: structure, genetic variability and inbreeding.
Animal, 13(1), 15-24.
https://doi.org/10.1017/S1751731118001180 Publication
Researcher Affiliations
- 1Department of Veterinary Medicine - Sportive Horse Research Center,University of Perugia,via S. Costanzo 4,06123 Perugia,Italy.
- 1Department of Veterinary Medicine - Sportive Horse Research Center,University of Perugia,via S. Costanzo 4,06123 Perugia,Italy.
- 1Department of Veterinary Medicine - Sportive Horse Research Center,University of Perugia,via S. Costanzo 4,06123 Perugia,Italy.
- 2Department of Agricultural,Food and Environmental Sciences,University of Perugia,Borgo XX Giugno,74, 06121 Perugia,Italy.
MeSH Terms
- Animals
- Female
- Genetic Variation
- Horses / genetics
- Horses / physiology
- Inbreeding
- Italy
- Male
- Pedigree
- Population Density
- Pregnancy
Citations
This article has been cited 18 times.- Asti V, Summer A, Ablondi M, Sartori C, Giontella A, Pilastro V, Mecocci S, Cappelli K, Mancin E, Oian A, Mantovani R, Capomaccio S, Sabbioni A. Selection signatures and inbreeding: exploring genetic diversity in five native horse breeds. BMC Vet Res 2025 May 16;21(1):346.
- Medeiros BB, Barcelos KMC, Andrade MO, Cristina da Paz Carvalho M, Miranda VR, de Oliveira Maia K, Reinhardt S, Patterson Rosa L. The Weight of Genetic Drift: A Pedigree-Based Evaluation of the Breton Horse Population in Brazil. Vet Med Int 2024;2024:4714077.
- Giontella A, Silvestrelli M, Cocciolone A, Pieramati C, Sarti FM. Breeding Value Estimation Based on Morphological Evaluation of the Maremmano Horse Population through Factor Analysis. Animals (Basel) 2024 Jul 31;14(15).
- Giontella A, Cardinali I, Sarti FM, Silvestrelli M, Lancioni H. Y-Chromosome Haplotype Report among Eight Italian Horse Breeds. Genes (Basel) 2023 Aug 9;14(8).
- Capomaccio S, Ablondi M, Colombi D, Sartori C, Giontella A, Cappelli K, Mancin E, Asti V, Mantovani R, Sabbioni A, Silvestrelli M. Exploring the Italian equine gene pool via high-throughput genotyping. Front Genet 2023;14:1099896.
- Cardinali I, Giontella A, Tommasi A, Silvestrelli M, Lancioni H. Unlocking Horse Y Chromosome Diversity. Genes (Basel) 2022 Dec 2;13(12).
- Klein R, Oláh J, Mihók S, Posta J. Pedigree-Based Description of Three Traditional Hungarian Horse Breeds. Animals (Basel) 2022 Aug 14;12(16).
- Criscione A, Mastrangelo S, D'Alessandro E, Tumino S, Di Gerlando R, Zumbo A, Marletta D, Bordonaro S. Genome-wide survey on three local horse populations with a focus on runs of homozygosity pattern. J Anim Breed Genet 2022 Sep;139(5):540-555.
- Ivanković A, Bittante G, Konjačić M, Kelava Ugarković N, Pećina M, Ramljak J. Evaluation of the Conservation Status of the Croatian Posavina Horse Breed Based on Pedigree and Microsatellite Data. Animals (Basel) 2021 Jul 18;11(7).
- Próchniak T, Kasperek K, Knaga S, Rozempolska-Rucińska I, Batkowska J, Drabik K, Ziȩba G. Pedigree Analysis of Warmblood Horses Participating in Competitions for Young Horses. Front Genet 2021;12:658403.
- Marín Navas C, Delgado Bermejo JV, McLean AK, León Jurado JM, Torres ARBYR, Navas González FJ. Discriminant Canonical Analysis of the Contribution of Spanish and Arabian Purebred Horses to the Genetic Diversity and Population Structure of Hispano-Arabian Horses. Animals (Basel) 2021 Jan 21;11(2).
- Giontella A, Cardinali I, Pieramati C, Cherchi R, Biggio GP, Achilli A, Silvestrelli M, Lancioni H. A Genetic Window on Sardinian Native Horse Breeds through Uniparental Molecular Systems. Animals (Basel) 2020 Sep 1;10(9).
- Perdomo-González DI, Sánchez-Guerrero MJ, Molina A, Valera M. Genetic Structure Analysis of the Pura Raza Español Horse Population through Partial Inbreeding Coefficient Estimation. Animals (Basel) 2020 Aug 6;10(8).
- Giontella A, Sarti FM, Cardinali I, Giovannini S, Cherchi R, Lancioni H, Silvestrelli M, Pieramati C. Genetic Variability and Population Structure in the Sardinian Anglo-Arab Horse. Animals (Basel) 2020 Jun 11;10(6).
- Ablondi M, Dadousis C, Vasini M, Eriksson S, Mikko S, Sabbioni A. Genetic Diversity and Signatures of Selection in a Native Italian Horse Breed Based on SNP Data. Animals (Basel) 2020 Jun 8;10(6).
- Lancioni H, Cardinali I, Giontella A, Antognoni MT, Miglio A. Mitochondrial DNA variation in the Italian Heavy Draught Horse. PeerJ 2020;8:e8996.
- Giontella A, Cardinali I, Lancioni H, Giovannini S, Pieramati C, Silvestrelli M, Sarti FM. Mitochondrial DNA Survey Reveals the Lack of Accuracy in Maremmano Horse Studbook Records. Animals (Basel) 2020 May 12;10(5).
- Giontella A, Sarti FM, Biggio GP, Giovannini S, Cherchi R, Pieramati C, Silvestrelli M. Genetic Parameters and Inbreeding Effect of Morphological Traits in Sardinian Anglo Arab Horse. Animals (Basel) 2020 May 2;10(5).
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
