The defining characteristics of pasture-based systems in temperate regions.

Pasture is an important source of feed for dairy and beef cattle in many parts of the world, but its predominant use in some dairy production systems such as those traditional to Western Europe, South America, and Oceania is relatively unique, with only 10% to 15% of global dairy products derived from such systems. Recently, pasture-fed dairy products have commanded premium international market prices as consumers perceive them to be superior to products from conventional confinement-based systems. There is, however, no international standard that defines the term grass/pasture fed and diverse definitions apply across different countries. To provide a practical definition of the dietary characteristics of pasture-based systems, we reviewed the literature from recent full-lactation farm systems experiments which have reported the proportion of grazed pasture in the total animal diet, in addition to grazing platform stocking rate (SR), grazing days per cow and per hectare without forage supplements, and concentrate supplementation (kg DM/cow). The final database contained 56 experimental comparisons published between 2008 and 2025. Based on the data, the proportion of grazed pasture in the total animal diet was described using linear regression according to 3 factors, namely, the number of full grazing days achieved without forage supplementation (no. of days), the grazing SR (cows/ha) on the grazing area, and the total level of concentrate supplementation (kg DM/cow). The results of the linear regression indicate that these 3 parameters explain a large part of the variation in grazed pasture proportion. Based on the data reported in these studies, we propose that a pasture-based dairy system can be defined as a system where the total diet of the dairy cow during the combined lactating and nonlactating period (equivalent to one complete year) contains in excess of 50% of grazed pasture on a DM basis, and where less than 15% of the total animal feed requirements are supplied from concentrate supplements (equivalent to approximately 1,000 kg DM/cow).