Abstract: The influence of copper and zinc supplements on milk
production performances and health indicators was tested in a 20-
week feeding trial, with 40 Holstein-Friesian lactating cows, devided
in four groups (copper, zinc, copper-zinc and control). Correlations of
the Cu and Zn plasma values with some animal performance criteria
of health (body condition score and somatic cell counts) and
production (milk yield, peak milk yield, fat and crude protein
content) were done. During the 140 days of the experiment, the two
added minerals caused a statistically significant increase (p < 0.05) of
their plasma values after the peak of the cows’ lactations. It was also
observed that subjects that have received copper and zinc
supplements had the lowest number of somatic cell counts in milk.
The Pearson correlation test showed a positive corellation (p = 0.007,
r = + 0.851) between the plasma Zn and the milk production. The
improvement of the nutritional status improved the milk production
performances of the cows as well as their health performances.