Colostrum and milk performance,and blood immunity indices and minerals of Holstein cows receiving organic Mn,Zn and Cu sources

摘要

Effects of supplementing the basal diets with Mn,Zn and Cu,as sulphate,glycine or methionine salts,on colostrum and milk performance,some blood immunity indices and blood minerals of pre-and postpartum Holstein cows were accessed.Forty cows in different groups received:1)a diet without supplementary Mn,Zn and Cu(control),2)a diet containing Mn,Zn and Cu sulphates,3)a diet containing Mn,Zn and Cu glycine,or 4)a diet containing Mn,Zn and Cu methionine with 10 cows per group from d 60 before calving(dry period)to d 100 of lactation.Dry matter intake(DMI),dry matter digestibility(DMD),colostrum and milk performance,milk somatic cell count(SCC),blood and milk total antioxidant capacity(TAC),immunoglobulin M(IgM)and immunoglobulin A(IgA),and blood Mn,Zn and Cu were determined.Dietary supplementation with Mn,Zn and Cu as methionine,glycine or sulphate salts had positive effects on DMD,DMI,colostrum and milk performance,milk SCC,and blood Mn and Zn.Addition of Mn,Zn and Cu in diets could increase(P0.05),however,the blood concentrations of IgA(except d 1 postpartum)and IgM in the cows supplemented with organic Mn,Zn and Cu were higher(P<0.05)than those in the cows receiving the sulphate sources of minerals.Overall,dietary supplementation of Mn,Zn and Cu as methionine,glycine or sulphate salts can improve colostrum and milk performance,blood Zn and Mn and immunity indices in Holstein cows and their new-born calves.Moreover,the organic sources of Mn,Zn and Cu have advantage over the sulphate forms in terms of the blood immunoglobulins.