Polymorphism of CAST gene in five sheep breeds in Bulgaria Ivona Dimitrova, Milena Bozhilova-Sakova, Atanaska Teneva, Tanya Ivanova and Ina Stoycheva E3S Web Conf., 262 (2021) 02026 Published online: 24 May 2021 DOI: 10.1051/e3sconf/202126202026