Phenotypic and genomic analyses of udder health in compost bedded pack barns based on microscopic differential cell count and specific mastitis pathogens

Abstract

New alternative housing systems, such as compost-bedded pack barns, attract increasing attention in dairy cow housing due to higher animal welfare, longevity and improved animal health. The mixture of bedding and cow excreta as well as an increased moisture in the compost can result in an increased presence of pathogens, which can invade the udder and cause mastitis. Udder health is one of the most important factors for dairy cows. Mastitis implies considerable costs for the farm and additionally causes severe losses due to a lower milk yield and deductions in the dairy due to increased somatic cell counts in the milk. Hence, mastitis is leading to one of the most important economic losses in milk production worldwide. The aim of this study was therefore to analyse and compare udder health in cows between the two housing systems, i.e., the compost-bedded pack barn and the conventional cubicle barn on a phenotypic and genomic level. Furthermore, new and even more detailed trait definitions for udder health were analyzed to evaluate their potential in the context of improving breeding strategies for udder health compared to previous traits.