Productive longevity of white-and-black cows of different genotypes CSN3 and DGAT1 Radik Shaidullin, Gazimzyan Sharafutdinov, Anastasia Moskvicheva, Rustam Ravilov and Ismagil Khakimov BIO Web Conf., 17 (2020) 00060 Published online: 28 February 2020 DOI: 10.1051/bioconf/20201700060