Using factor analysis in beef cattle breeding Alexey Zelenkov, Alexey Ermakov, Galina Zelenkova, Ivan Gorlov, Alexander Pakhomov, Sergei Tresnitskii and Tatyana Derezina E3S Web Conf., 135 (2019) 01088 Published online: 04 December 2019 DOI: 10.1051/e3sconf/201913501088