Genomic characterization, preservation and optimum contribution selection of Croatian dairy sheep

ABOUT

Profitability of Istrian and Pag sheep dairy orientated homesteads depends on performances of Istrian (IS) and Pag (PS) sheep breeds within the existing ecological niches. Genetic improvement of dairy performance via selection is important for the economic viability of these breeds, while maintenance of the underlying genetic variability is vital for their “plasticity” and adaptability to possible environmental changes in the future. Recent rapid developments of high throughput molecular genetic methods have provided conditions for efficient genotyping of large number of loci in the genome (SNPs) for affordable price, which opens the possibility for widespread usage of genomic information in practice (e.g., genomic selection, GS). Given the potential benefits of the GS, the transition to this system is expected in the near future in all livestock breeding programs. Since the transition to GS and its’ long-term viability demand substantial investments, it is necessary to analyze in detail the potential of long-term GS implementation in IS and PS populations. Based on a thorough analysis of the available data in the populations of IS and PS, aim of this project is to evaluate the implementation of Optimum Contribution Selection (OCS) which simultaneously maximizes genetic gain and minimizes loss of genetic variability. This is achieved with the selection of genetically high-performant animals that have a minimal possible group (collective) genetic relationship. Two-fold benefit of this study based on the OCS approach will be reflected through: 1) “ex situ in vitro” preservation of the optimal genome representing the result of synergistic activity of man and nature through the history and 2) in situ in vivo preservation of the breeds through their improved genotypic profile regarding dairy traits. These project will impact long-term sustainability of IS and PS, which will benefit the breeders, consumers and corresponding (dairy) industries. By showing how to optimize selection with maintenance of genetic diversity, the results could also be beneficial to other sheep and livestock breeding programs.

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PROJECT: IP-2019-04-3559

TOTAL VALUE: 793.700,00kn

PROJECT DURATION: 01.01.2020.-31.12.2023.

NEWS

21st Exhibition of Pag sheep and cheese & presentation of the “Pag sheep” monograph with the results of the HRZZ project (IP-2019-04-3559);

16-17 June 2023, Novalja, Island Pag

Sampling of Istrian Sheep

Sampling of Istrian Sheep

Out of the total number of sheep under selection, more than 700 Istrian sheep from 12 farms have been sampled so far.

Sampling of Pag Sheep

Sampling of Pag Sheep

Out of the total number of sheep under selection, about 240 Pag sheep from two farms have been sampled so far.

EQUIPMENT AND WORKING MATERIAL

Computer HP

Sampling equipement - Allflex

Compressor cooler CFX-28

Books

  1. Mrode, R.A. (2014): Linear Models for the Prediction of Animal Breeding Values. 3rd Edition, CABI Publishing, UK.
  2. Weller, J.I. (2016): Genomic Selection in Animals. John Wiley & Sons. New Jersey.
  3. Simm G. (2002): Genetic Improvement of Cattle and Sheep. Oxford University Press. UK.

GALLERY

Sampling of Pag sheep

Sampling of Istrian sheep

Photos: AZZRI Pazin

PUBLICATION

Ramljak, J.; Špehar, M,; Držaić, V.; Kasap. Genomic patterns of homozygosity in Istrian sheep. 58th Croatian & 18th International Symposium on Agriculture, Dubrovnik, Croatia, 2023. PPTPDF 

Kasap, A.; Mijadžiković, Z.;  Smutni, B.; Mioč, B.; Špehar, M. Estimation of inbreeding coefficient and generation interval in Pag Sheep – baseline for development of optimum contribution selection. 58th Croatian & 18th International Symposium on Agriculture, Dubrovnik, Croatia, 2023. PPTPDF 

Špehar, M.; Ramljak, J.; Kasap, A. Assessing Among Flocks Genetic Diversity in Istrian Sheep to Define a Framework for Optimum Contribution Selection. Animal Science Days, Zadar, Croatia, 2022. PDF 

Kasap, A.; Ramljak, J.; Špehar, M. Increasing Effective Population Size by Strengthening Genetic Connectedness Between flocks: Case Study on Pag Sheep Breed. Animal Science Days, Zadar, Hrvatska, 2022. PDF

Špehar, M.; Ramljak, J.; Kasap, A. Genome-wide association study for daily milk yield in Istrian dairy sheep. 73rd Annual Meeting of the European Federation of Animal Science / EAAP Scientific committee (ed.) Porto, Portugal, 2022. 695.PDF 

Ramljak, J.; Špehar, M.; Kasap, A.; Mioč, B.; Širić, I.; Ivanković, A.; Barać, D.; Barać, Z.; Držaić, V. SNP-based genetic diversity in Pag sheep – preliminary results. 73rd Annual Meeting of the European Federation of Animal Science / EAAP Scientific committee (ed.) Porto, Portugal, 2022. 696. – PDF

Kasap, A.; Ramljak, J.; Špehar, M. Estimation of linkage disequlibrium in Pag and Istrian sheep breed: towards genomic optimum contribution selection. World Congress on Genetics Applied to Livestock Production / WCGALP Scientific committee (ed.) Rotterdam, Netherland, 2022. 1-4.PDF 

Špehar, M.; Ramljak, J.; Poslon, V.; Kasap, A. Partitioning of genetic trends by flock and gender in Istrian sheep breed. World Congress on Genetics Applied to Livestock Production / WCGALP Scientific committee (ed.) Rotterdam, Netherland, 2022. 1-4.PDF 

Kasap, A.; Božulić, L.; Ramljak, J.; Mioč, B.; Špehar, M. Partition of genetic trend for milk yield by gender and flock in Pag sheep. 57th Croatian & 17th International Symposium on Agriculture, Book of Abstracts. Rozman, V., Antunović, Z. (ed.). Osijek, Croatia, 2021. 462-466.PDF

Kasap, A.; Špehar, M., Gorjanc, G., Ivanković, A., Barać, Z., Ramljak, J. Analysis of genealogical information and estimation of population parameters in population of Istrian sheep. 56th Croatian & 16th International Symposium on Agriculture, Book of Abstracts. Rozman, V., Antunović, Z. (ed.). Osijek, Croatia, 2021. 258-258.PDF

Kasap, A.; Špehar, M.; Mioč, B.; Držaić, V.; Širić, I.; Jurković, D.; Ramljak, J. The impact of age at first lambing on some dairy traits in Istrian sheep breed. 56th Croatian & 16th International Symposium on Agriculture, Book of Abstracts. Rozman, V., Antunović, Z. (ed.). Osijek, Croatia, 2021. 257-257. – PDF

Ramljak, J., Špehar, M., Ivanković, A., Kasap, A. Assessing genetic diversity of Pag sheep through pedigree analyses. Book of Abstracts of the International Symposium 29th Animal Science days. Gödöllő, Hungary, 2021. 1-1.PDF

Kasap, A.; Ramljak, J.; Špehar, M. Estimation of genetic connectedness between flocks in population of Istrian sheep. Book of Abstracts of the International Symposium 29th Animal Science days. Gödöllő, Hungary, 2021. 1-1. – PDF

Špehar, M.; Ramljak, J.; Kasap, A. Partitioning of genetic trends by flock in Istrian sheep breed. Book of Abstracts of the 72nd Annual Meeting of the European Federation of Animal Science. EAAP scientific committee (ed.). Davos, Switzerland, 2021. 228-228. – Link, PDF

Kasap, A.; Ramljak, J.; Špehar, M. Genomic PCA – a proxy for monitoring genetic connectedness between flocks (case study on sheep). Book of Abstracts of the 72th Annual Meeting of the European Federation of Animal Science / EAAP scientific committee (ed.). Davos, Switzerland, 2021. 451-451. – Link, PDF

Špehar, M.; Ramljak, J.; Kasap, A.; Estimation of genetic parameters and the effect of inbreeding on dairy traits in Istrian sheep. Italian Journal of Animal Science 2021, 1,  331-342, doi.org/10.1080/1828051X.2022.2031320.  – Link, PDF

Kasap, A.; Ramljak, J.; Mioč, B.; Držaić, V.; Širić, I.; Jurković, D.; Špehar, M. The Impact of Age at First Lambing on Milk Yield and Lactation Length in a Population of Istrian Sheep under Semi-Intensive Management. Animals 2021, 11, 1604. – Link, PDF

Kasap, A.; Ramljak, J.; Špehar, M. Estimation of Population-Specific Genetic Parameters Important for Long-Term Optimum Contribution Selection—Case Study on a Dairy Istrian Sheep Breed. Animals 2021, 8, 2356.Link, PDF

Dissemination

 7.  26th International Science Symposium of Biometry BIOSTAT 2023;

14-17 June 2023, Zadar

 6.  24th Conference of sheep and goat breeders in the Republic of Croatia and 23th exhibition of sheep and goat chesses;

14-25 October, Seget Donji

5.  “Plodovi zemlje” reportage on HRT1 program “Saving the Istrian sheep”

10 April 2022, Pazin

4. 23.   Conference of sheep and goat breeders in the Republic of Croatia and the 22nd exhibition of Croatian sheep and goat cheeses;

30 November – 1 October 2021, Rabac

3. Article in “Ovčarsko kozarski list” – “Development of a strategy for the implementation of selection with optimal contributions in the function of genetic progress and preservation of genetic diversity for the properties of dairy products”

2. Staff training: learning how to work with databases of genetic material,

January, 2021.

1. 22nd Conference of Sheep and Goat Breeders in the Republic of Croatia,

25 November 2020, on-line;

Špehar, M., Ramljak, J., Kasap, A. (2020):

Development of a strategy for the implementation
of selection with optimal contributions in the function of genetic progress and conservation
of genetic diversity for dairy traits.

Link, PDF

RESEARCH GROUP

Assoc. Prof. Jelena Ramljak, PhD, project manager

University of Zagreb Faculty of Agriculture, Department of Animal Science and Technology

Prof. Boro Mioč, PhD

University of Zagreb Faculty of Agriculture, Department of Animal Science and Technology

Assist. Ante Kasap, PhD

University of Zagreb Faculty of Agriculture, Department of Animal Science and Technology

Valentino Držaić, PhD

University of Zagreb Faculty of Agriculture, Department of Animal Science and Technology

Ivan Pocrnić, PhD

University of Edinburgh, UK

Prof. Gregor Gorjanc, PhD, Advisor

University of Edinburgh, UK

Prof. Ante Ivanković, PhD

University of Zagreb Faculty of Agriculture, Department of Animal Science and Technology

Assist. Prof. Ivan Širić, PhD

University of Zagreb Faculty of Agriculture, Department of Animal Science and Technology

Marija Špehar, PhD

Croatian Agency for Agriculture and Food (CAAF)