The inter-breed crossing (crossbreeding) permits one to introduce new alleles, extend genetic diversity, and achieve desired phenotypic characteristics of initial breeds. On the other hand, crossbreeding may cause a decrease in genetic differentiation of indigenous breeds due to loss of the part of their unique allele pool. The objective of the present work was to investigate the effect of crossbreeding on the allele pool variability of Russian Black and White cattle by using 10 microsatellite loci (BM1818, BM2113, ETH10, ETH225, TGLA122, TGLA126, TGLA227, ILST005, ETH185, and ILST006).
The study was performed with purebred pedigree bulls of the Russian Black and White breed (BW_PB, n = 14) and two groups of their crosses with Holsteins carrying 25,0–62,5 % (BW_KR1, n = 16) and less than 12,5 % of the Black and White gene pool (BW_KR2, n = 67). Purebred Holstein bulls (HOLST, n = 42) were used as a reference group. It was found that the increase in Holstein’s blood could lead to the observed decrease in genetic diversity evaluated by the average number of effective alleles per loci (from 4,59 ± 0,46 to 3,87 ± 0,53), by the value of the Shannon index (from 1,60 ± 0,13 to 1,46 ± 0,14) and by the observed heterozygosity degree (from 0,779 ± 0,053 to 0,687 ± 0,055). It is shown that crossbreeding with Holsteins increases the genetic similarity to HOLST: Fst = 0,058, 0,036, and 0,026; Rst = 0,088, 0,060, and 0,050; DNei = 0,306, 0,178, and 0,123 for BW_PB, BW_KR1, and BW_KR2, respectively. Decrease in the genetic difference between the Black and White breed and Holsteins due to crossbreeding is confirmed by cluster analysis. Thus, evaluation of the allele pool and the level of genetic variability in populations are necessary for the efficient management of farm animal genetic recourses.
About The Authors:
N. A. Zinovieva. L.K. Ernst Institute for Animal Husbandry, Dubrovitsy, Podolsk district, Moscow region, Russia, Russian Federation
V. A. Bagirov. L.K. Ernst Institute for Animal Husbandry, Dubrovitsy, Podolsk district, Moscow region, Russia, Russian Federation
1. Dolmatova I.Yu., Zinov’eva N.A., Gorelov P.V., Il’yasov A.D., Gladyr’ E.A., Traspov A.A., Sel’tsov V.I. Osobennosti allelofonda bashkirskoĭ populyatsii simmental’skogo skota po mikrosatellitam. S.-kh. biologiya. 2011;6:70-74.
2. Bjelland D.W., Weigel K.A., Vukasinovic N., Nkrumah J.D. Evaluation of inbreeding depression in Holstein cattle using whole-genome SNP markers and alternative measures of genomic inbreeding. J.Dairy Sci. 2013;96(7):4697-4706. DOI: 10.3168/jds.2012-6435
3. Hiemstra S.J., Haas Y., Mäki-Tanila A., Gandini G. Local cattle breeds in Europe Development of policies and strategies for self-sustaining breeds. The Netherlands: Wageningen Academic Publishers, 2010.
4. Muir W.M., Wong G.K.-S., Zhang Y., Wang J., Groenen M.A.M., Crooijmansd R.P.M.A., Megensd H.-J., Zhange H., Okimotof R., Vereijkeng A., Jungeriusg A., Albersg G.A.A., Lawley C.T., Delany M.E., MacEachern S., Cheng H.H. Genome-wide assessment of worldwide chicken SNP genetic diversity indicates significant absence of rare alleles in commercial breeds. Proc. Natl. Acad. Sci. 2008;105(45):17312-17317. DOI:10.1073/pnas.0806569105
5. Nei M., Tajima F., Tateno Y. Accuracy of estimated phylogenetic trees from molecular data. II. Gene frequency data. J. Mol. Evol.1983;19(2):153-170.
6. Peakall R., Smouse P.E. GENALEX 6: genetic analysis in Excel. Population genetic software for teaching and research. Mol. Ecol. Notes.2006;6:288-295. DOI: 10.1111/j.1471-8286.2005.01155
7. Pritchard J.K., Stephens M., Donnelly P. Inference of population structure using multilocus genotype data. Genetics. 2000;155(2): 945-959.
8. Sustainable diets and biodiversity: direction and solutions for policy, research and action. Eds B. Burlingame, S. Dernini. Rome: FAO, 2010.
9. The State of the World’s Animal Genetic Resources for Food and Agriculture — in brief. Eds D. Pilling, B. Rischkowsky. Rome: FAO, 2007.
10. Van Raden P.M., Olson K.M., Null D.J., Hutchison J.L. Harmful recessive effects on fertility detected by absence of homozygous haplotypes. J. Dairy Sci. 2011;94(12):6153-6161. DOI: 10.3168/jds.2011-4624