Recent Advances in Genetic Evaluation of Italian Holstein: Results from Latteco Project

The evolution of breeding objectives is crucial to reflect future market demands and law requirements, but also to meet farmers’ requests operating in different scenarios. Latteco is an ongoing project financed by the Italian Minister of Agriculture, Food, Forestry, and Tourism aiming at maintaining genetic diversity, improving animal welfare, and reducing environmental impact of dairy cattle through animal breeding. The first output of the present project was the development of the udder health selection index, whose aim is to reduce incidence of clinical mastitis by exploiting different patterns of somatic cell score throughout lactation. In this selection index, four different traits, defined from somatic cell score variation, are combined together with different emphasis depending on the genetic covariances existing among traits and between each trait and clinical mastitis. Another output from the project was the revision of the aggregate female fertility selection index by exploiting data from pregnancy scanning, and by including information on body condition score measured on cows as well as heifer fertility. The new aggregate fertility index is a combination of eight traits which are genetically correlated to conception rate at first insemination, which represents the breeding goal of the index. With the official release of December 2018, it was published the third National breeding objective called “Cheesemaking and Sustainability Index – Parmigiano Reggiano” (ICS-PR). This breeding objective is intended for maximizing profit of farmers operating in a market situation in which milk is processed into long-ripened cheeses. The economic values of the traits contributing to the index where estimated based on field data in order to properly quantify the relative emphasis to be placed at each production, fertility, calving ease, longevity, udder health, and type traits. Finally, other relevant parts of the project such as resistance to subclinical ketosis, and feed efficiency, as well as the revision of Production, Type, and Functionality (PFT) breeding objective, are in progress and are expected to be distributed to dairy farmers during 2020.