The milk fingerprint of Sardinian dairy sheep: quality and yield of milk used for Pecorino Romano P.D.O. cheese production on population-based 5-year survey

The Pecorino Romano P.D.O. is the main sheep cheese produced in Italy and the first one among the sheep cheeses, in terms of quality and value, exported from the European Union. About half of the sheep milk produced in Italy is processed into this type of cheese by 36 dairies belonging to the Pecorino Romano Consortium. Eight million records of biweekly analyses of milk collected within a 5-year period from farms delivering their milk to the aforementioned consortium were analysed in this work. Monthly evolution curves were plotted for fat, protein, lactose, pH, NaCl, SCC, bacterial load and principal fatty acids (FAs). Due to the seasonal production systems of Sardinian sheep, monthly evolution of milk fat and protein contents and cheese yield are directly linked to the lactation curve pattern and the pastures quantity and quality. Also, the FA profile of milk is affected by grass availability and quality in both early and mid-lactation, whereas it is influenced by the energy balance of ewes in late lactation. Cheese yield equation was computed based on fat and protein contents and considering the variability among dairies in technological processes used in transforming Sarda sheep milk to Pecorino Romano P.D.O. These data could be a relevant basis to set-up future grids of milk payments based on quality standards. Moreover, they could be useful to formulate administrative policies on the dairy sector with the prospective to improve milk quality of Sardinian sheep destined to the Pecorino Romano production.Highlights The yield of Pecorino Romano P.D.O. (PR) is linked to fat and protein content of milk and it depends on the industrial processes adopted by each dairy Monthly variation of milk composition is of high interest for the PR producers to program the output of their milk-processing plans The content and monthly evolutions of principal fatty acids are important to determine the nutritional and technological properties of PR