An important parameter for evaluating the technical and economic value of a batch of cocoons, along with silkiness (i.e., the ratio of the mass of shells to the mass of these cocoons as a percentage), is the volume stiffness of cocoons (i.e., the ratio of the external force acting on the cocoon to the amount of deformation of the cocoon shell). We propose to measure the volumetric stiffness using the FTI - 1M device, when an additional load is placed on the lid, which compresses the layer of live cocoons in the measuring container in height. It is obvious that the thinner the shell is, the greater the deformation of the cocoon layer will be. In addition, the volume stiffness was measured in this work by piece with a VC stiffener (i.e., a device for measuring the rigidity of the cocoon shell) separately for each breed with an error of 3%. These additional measurements confirmed the accuracy of the results obtained on the FTI - 1M device for volumetric stiffness. As a result, we obtained correlations between bulk stiffness and silkiness, as well as dependencies between bulk stiffness and shell thickness for various new breeds of silkworm cocoons: Marhamat, Marvarid, Asaka, and Yulduz. Linear dependencies are constructed based on the data presented in the corresponding table. The volume stiffness of various breeds of live cocoons increases both with increasing silkiness and the thickness of their shell. This is quite understandable, since the greater the silkiness, the thicker the shell, and therefore the greater the volume stiffness of the cocoon. Based on the results obtained, it is concluded that the silkiness of the Marvarid breed was lower than that of other breeds. Thus, this paper shows the possibility of determining the prospects of a particular breed by measuring and evaluating cocoons based on the correlation between silkiness and bulk stiffness or silkiness and the thickness of the shell of a cocoon sample.