EAAP – 60th Annual Meeting, Barcelona 2009 517
Session 47 Poster 9
Session 47 Poster 8
Effects of feeding zinc sources on biochemical parameters, concentration of some hormones and zinc
in serum of Holstein dairy cows
Sobhanirad, S.1, Valizadeh, R.2, Moghimi, A.3 and Naserian, A.2, 1Azad university of Mashhad, Animal
science, Golbahar - Mashhad, 9195648499, Iran, 2Ferdowsi University of Mashhad, Animal science,
Azadi sq., 917751163, Iran, 3Ferdowsi University of Mashhad, Biology, Azadi sq., 917751163, Iran;
ssobhani2002@yahoo.com
Fifty-four lactating dairy cows randomly allocated to one of three groups. Ttreatment groups received the
basal diet with no supplemental Zn (control), basal diet plus 500 mg of Zn/kg of DM as ZnSO4.H2O (ZnS)
and basal diet plus 500 mg of Zn/kg of DM as Zinc methionine (ZnM). This experiment was started in the
first phase of lactation (35±3 days after parturition). The data were analysed using the mixed procedure
of SAS (9.1) for a block randomized design with repeated measures. Plasma and serum were taken from
samples of blood on 0, 2, 4, 6, 8 and 10 weeks of experiment. The number of red blood cell, haemoglobin,
MCHC, number of platelet and serum zinc in the ZnM and ZnS groups were significantly higher than control
group (P<0.05). Mentioned factors were also higher (P<0.05) in dairy cattle that received ZnM than ZnS.
There were no differences for WBC, PCV, MCH and PLT. There were not significant differences among
different sources of Zn for ALP, but LDH and SOD in ZnM group were significantly higher than ZnS. In
the current study, lactating dairy cattles fed ZnM had higher concentration of Zn in blood serum, some of
haematological parameters and enzyme activity of LDH and SOD which is consisted with previous studies.
In this study, despite the diet was fortified at levels exceeding the NRC requirements, improvements in
blood parameters and enzyme activities of LDH and SOD were observed when organic Zn sources