Influence of organic mineral supplement MultiMix on the calving interval in dairy cattle

Abstract

The aim of the study was to investigate the effect of MultiМix supplement on the calving interval in dairy cattle. The production experiment was performed in the Experimental base of the Agricultural Institute – Stara Zagora with two groups of 15 lactating cows each (one experimental and one control) between May and July 2019. Groups were fed rations balanced with regard to milk productivity and body weight of animals. The supplement MultiМix was added to the water of experimental cows in line with recommendations of the manufacturer. Evaluation of unbiased statistical values for the effect of MultiМix supplement with regard to specific studied factors was done by Principal Component Analysis (PCA). The model included other factors as well – age, milk fat to milk protein ration, and daily milk yield (kg). A statistically significant between-group difference was found out in cows, as those supplemented with the organic mineral supplement MultiМix had a longer calving interval (by 39.65 days), higher daily milk yield (by 4.12 kg), and higher milk fat/protein ratio (by 0.10). Weak positive correlations were found out between milk fat/protein ratio and all other parameters – from 0.116 tо 0.166. Weak negative relationships were identified between calving interval and milk yield (-0.067), as well as between milk yield and age of cows (-0.079). The strongest correlation was found out between cow age and calving interval duration. Additional, more prolonged investigations are necessary to evaluate the effect of the tested organic supplement on reproductive performance of cows.