1. Executive Agency for Selection and Reproduction in Animal Breeding, 1766 Sofia, Bulgaria
2. Department of Animal Husbandry—Ruminants and Dairy Farming, Trakia University, 6000 Stara Zagora, Bulgaria
3. Scientific Center of Agriculture, Agricultural Academy, 8300 Sredets, Bulgaria
4. Department of Experimental Parasitology, Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
5. Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
6. Research Centre of Stockbreeding and Agriculture, Agricultural Academy, 4700 Smolyan, Bulgaria
7. Department of Animal Diversity and Resources, Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 25, 1113 Sofia, Bulgaria