Clustering Limousin Candidate Bulls Based on Their Measured Production Traits and Genomic Scores

This chapter aimed to define type categories of Limosin breeding bulls by cluster analysis, based on their central performance test results, both measured in the test station and obtained by DNA chips. Production control and performance tests are inevitable, important parts of the breeding activity. Various techniques can be applied during these, but it is evident to use accurate, fast, and standardised methods for all traits important according to the breeding aim. The production of purebred Limousin candidate bulls (n = 40) were analysed between 2018-2020. Candidate bulls were kept in small groups (2-9) at the test station, fed with meadow hay, alfalfa ad libitum and dosed fodder. Traits studied were the following: finishing live weight, daily weight gain during the test (g/day) and genomic scores (GS) for 8 production and reproduction traits (growth vigor, muscularity, frame size, calving difficulty, bone, milk production, pelvis). Different types within breeds can produce differently in various environments, suitable for different selection criteria and whether and animal is used in sire line or in maternal one also depends on type. The animals grouped into the first cluster showed high growth capacity and excellent growth intensity with good frame size, but at the same time with slightly less favorable bone fineness. The frame size of the individuals belonging to the second and third groups is not outstanding, however, their bone fineness is remarkable. Applying of the K-means cluster analysis can provide the breeders fast and useful information. These kinds of studies can help to understand the relationships among given components of the type.