Formation of an expanded linear conformation traits list for the dairy cattle based on international and Russian experience

Along with the pedigrees and productivity of animals, the evaluation of linear conformation traits (such as rib structure, rump angle, legs set and udder depth) is an important task in assessing the estimated breeding value of dairy cattle. Despite the existing international standard of the International Committee for Animal Recording (ICAR), which regulates the study of the cattle exterior, different countries still use their own significantly varying lists of linear traits and characteristics. This leads to a potential difficulty in animal comparison, for example, when selecting calves for purchase. In particular, the analysis of linear conformation traits from 14 countries showed that only 50 % of the main ICAR traits were simultaneously present in all lists. A similar analysis for Russia also revealed the presence of varying conformation traits in different regions. Although the Russian lists turned out to be more homogeneous than the international ones, they still differed from the ICAR, including only 77 % of the main linear traits at the same time.The further development of domestic breeding and the process of data unification can be facilitated by expanding ICAR conformation traits list. The proposed expanded list takes into account the already accumulated traits from Russian regions aas well as ICAR linear traits in order to increase the gathered data volume. As a result, it is expected to collect a total of 29 linear conformation traits, which will enable the best dairy cattle description and will improve the accuracy of calculations of the Russian animals breeding index.