[en] Temperature dependence of magnetic susceptibility χ(T) and magnetization around the Curie point of CdCr₂Se₄ monocrystals doped by silver has been studied experimentally. The dependence (1/x) (T) can be approximated by two linear segments; in the area of 300 K a break in the dependence is detected, which testifies to the change in effective magnetic moment of the Cd_1-xAg_xCr₂Se₄ compound at the given temperature. Effective magnetic moment in the low-temperature range is much higher than the one in the high-temperature range. It is assumed that the increase in the effective magnetic moment below 300 K is caused by the presence of impurity ferrons, and on this basis magnetic moment of one ferron is determined. For the case of weak additives its value reaches hundreds μ_B. T∼300 K is the temperature of impurity ferron destruction. Using the data on magnetization and susceptibility, exchange integrals of the Cd_1-xAg_xCr₂Se₄ monocrystals are calculated by the Baltzer and Voitovich method, on this basis values of p-d exchange for all doped samples are found