The extensive use of uncontrolled crossbreeding with exotic specialized breeds
References
GEORGESCU, S. E., MANEA, M. A., ZAULET, M., & COSTACHE , M. (2009). Genetic diversity among Romanian cattle breeds with a special focus on the Romanian Grey Steppe Breed. Romanian Biotechnological Letters, 14(1), 4194–4200. http://www.rombio.eu/rbl1vol14/1-5/15_Georgescu_bt.pdf
Porter, V. & Mason, I. L. (2002). Mason’s World Dictionary of livestock breeds, types and varieties (5th ed.). Wallingford, Oxfordshire, UK: CABI.
Porter, V., Alderson, L., Hall, S. J. G., & Sponenberg, D. P. (2016). Mason’s World Encyclopedia of Livestock Breeds and Breeding: 2 volume pack (1st ed.). Wallingford, Oxfordshire, UK: CABI.
Socol, C. T., Iacob, L., Mihalca, I., Criste, F. L., Șonea, C. G., & Doroftei, F. (2015). Romanian Gene Bank: Perspectives and Aspects for Farm Animal Genetic Resources Conservation. Animal Science and Biotechnologies, 48(1), 394–398.