Relationship between Conformation Traits and Lifetime Production Efficiency of Cows

Analysis was made of the relationship between conformation traits and lifetime production efficiency of the cows that first calved in 2000 and represented the active population in the Pomorze and Kujawy regions of Poland. The CORR Pearson procedures of SAS package were used in the statistical calculations. It was found that there is a statistically significant relationship, weak or low on the Guilford scale, between conformation traits and lifetime production efficiency of the cows, which is slightly higher for milk yield than for longevity. The type and conformation traits appear to be more suitable than the detailed traits for predicting the lifetime production efficiency of cows. Lifetime performance was most strongly related to the overall score and udder score ( ), followed by the scores for type and conformation and legs and feet ( ), and detailed traits such as udder width and dairy character ( ). The highest positive effect on longevity was exerted by udder score and legs and feet ( ) and among detailed traits by udder placement ( ) and fore udder attachment ( ). 1. Introduction The production efficiency of cows is closely related to milk yield in successive lactations and longevity. It is thought that longevity (which is measured in terms of lifespan, length of productive life, and survival to a certain age or calving) is one of the most important indicators of lifetime production efficiency of the cows. Cows with long productive lives have higher milk and milk component yields during their lives and give birth to more calves, and herd replacement costs decrease [1, 2], when summing up the results of cow longevity studies conducted in Polish research centres. Sawa [3] reported that cows in Poland are culled at 4.5 to 6.6 years of age, which is too early considering the natural lifespan of a cow (18–20 years) and that lifespan has a significant effect on the economic result of production [1]. A similar situation is found in Germany [4, 5]. Animal conformation is a very important trait, and in cattle it serves as a basis for selection of cows in breeding herds while accounting for the fact that cattle conformation is associated with production and nonproduction traits, and thus with production efficiency [6–11]. According to Guliński et al. [7], the conformation traits that are most related to dairy performance include udder width ( ), angularity ( ), overall score and type, and conformation ( ). A similar view is held by Chabuz et al. [12], who showed that milk yield was related most closely to conformation score on a 100-point scale ( ) and