Comparison and evaluation of Copper, Zinc and Iron status in serum and diets of industrial and semi-industrial dairy Holstein cattle in warm and cold season

AbstractThis study was conducted to evaluate the copper (Cu), zinc (Zn) and Iron (Fe) status in the industrial (n=12) and semi-industrial (n=12) dairy cattle farms from Isfahan city. A factorial experiment in a completely randomized block design consisting four blocks (North, South, West and East) was used. Effects of season in two levels (cold and warm) and cow-rearing practices in two levels (industrial and semi-industrial) on Cu, Zn and Fe concentrations in blood serum of 240 Holstein lactating dairy cows (after second calving, after peak of milk production, averaging 610±50 Kg BW, 30Kg daily milk yield and 170±20 days milking period) were studied. Blood samples were collected from the jugular vein of 5 dairy cows in each farm randomly. In industrial farms diet samples were collected from total mixed rations (TMR) and in semi-industrial farms, the samples were separately collected from forage and concentrates. To assess the Cu, Zn, Fe status in blood serum and diet, concentrations of the elements were determined by atomic absorption spectrophotometry (AAS). The mean concentrations of selected elements in serum were found to be similar in both season in industrial farms. The mean concentrations of Cu and Zn in Serum samples from semi-industrial farms in winter were higher than summer (P