Even though legumes used as forage are good sources of Ca, high lactating dairy cows still express signs of acute deficiencies. A study using random block design of three localities, three consecutive mowing and three maturity stages of alfalfa on Calcium content of leaves and stems of alfalfa was done. Maturity stages were: vegetative (no visible buds), bud stage (no visible flowers) and bloom stage (10-15% flowers). After collecting whole biomass from one square meter, a subsample was taken and after separation of leaves and stems, standard protocol of drying and grinding was performed. Results show significant effect of maturity stage with the highest Ca content in leaves (p<0.05) as compared with whole plant and alfalfa stems. The highest Ca content of leaves was observed at the beginning of flowering (2.43±0.0797), while bud stage resulted in higher Ca concentration (1.57 and 0.88% respectively). Due to significant differences observed between maturity stages for all types of samples, it may be concluded that stage of harvesting of alfalfa and/or proper determination of Ca content of alfalfa should be seriously considered in ration formulations of animals.