The article presents the results of assessing the peculiarities of muscle development in purebred Bestuzhev bull-calves (group I), crossbred bull-calves (1/2 Simmental x 1/2 Bestuzhev – group II), purebred Bestuzhev steers (group III), and crossbred steers (1/2 Simmental x 1/2 Bestuzhev – IV group). It was found that due to the manifestations of the effect of crossing, the crossbred young bulls were superior to the purebred ones in terms of the development of the muscles in the spinal column, limb-girdle, and thoracic and pelvic limbs. With that, the degonalization of the calves reduced the growth rate in both the purebred and the crossbred calves. Therefore, the steers were inferior to the bull-calves in terms of the development of both individual muscles and their groups in all anatomical areas of the body. The results of the study showed that the differences between the groups in the development of the muscles are due to the uneven growth rate of the standard muscle groups under the influence of the genotype and the gender.