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

Table 3

Mean dry matter (DM)-intake (kg/d) as well as copper and zinc intake (mg/d).

	DM-intake	Copper-intake	Zinc-intake
Group A (n = 30)	17.3 ± 3.3	${193}^{\text{a}}$ ± 39	${1041}^{\text{a}}$ ± 215
Group B (n = 30)	17.4 ± 3.2	${395}^{\text{b}}$ ± 78	${1993}^{\text{b}}$ ± 397
Lactation 1 (n = 38)	${16.4}^{\text{a}}$ ± 2.9	277 ± 111	1428 ± 540
Lactation 2 (n = 22)	${19.1}^{\text{b}}$ ± 3.1	322 ± 128	1662 ± 622

a < b; $P<.05$.