Hypocalcaemia is an important disorder associated with an increased risk of metabolic diseases, and many studies have been going on for decades. This study investigated the effects of anionic and zeolite with an oral Ca bolus in the prepartum phase on milk yields and compositions, and plasma Ca concentrations, blood metabolites and the prevalence of some reproductive disorders in dairy cows after parturition. Ninety pregnant non-lactating Holstein-Friesian cows were randomly assigned to three isoenergetic diets and their counterparts using an oral Ca bolus: (1) Control (CON): low Ca (0.44%); (2) Anionic (ANI): high Ca (1.00%); (3) Zeolite (ZEO): low Ca (0.44%). The feed and energy intakes of the CON and ZEO groups were higher than the ANI group. The raw milk yield, Pr%, and feed efficiency did not differ between the groups, while the corrected milk yield, fat% and total corrected milk yield at 305 days differed between groups. Total plasma and the ionized Ca concentration of the ANI and ZEO groups, at calving time and in 6, 12, 24 and 48 h after that, were higher than in the CON group. The frequencies of hypocalcaemia and reproductive disorders in the ANI and ZEO groups were lower than in the CON. The blood metabolite levels in the CON group were higher than in other groups. In conclusion, the ANI and ZEO diets and their counterparts supplemented with an oral Ca bolus improved the milk production traits, plasma calcium and metabolites concentration and also effectively prevented reproductive disorders.
Keywords: anionic and zeolite; blood metabolites; dairy cows; hypocalcaemia; milk traits; reproductive disorders.