Assessment of Reference Values for Copper and Zinc in Blood Serum of First and Second Lactating Dairy Cows

Table 4

Calculated reference ranges for copper ($\mu$mol/L) in dependence on the different feeding groups (A and B) and lactations (1 and 2).

	Parametric calculation	Non parametric calculation
Group A (n = 170)	6–17	8–18
Group B (n = 172)	7–18	8–19
Lactation 1 (n = 212)	6–17	8–19
Lactation 2 (n = 130)	7–17	8–18