Heifers of the black-spotted breed with a prolonged duration of embryonic development at the age of 20 and 90 days had the lowest live weight, the highest indicator was with an average, intermediate - with a short duration of embryogenesis. Animals with prolonged intrauterine development probably lagged behind representatives of other groups in terms of mass. The same sequence was preserved in their 6-month-old age. The low level of nutrition of females had the greatest impact on parts of the body of the fetus that develop late - the lumbar region, pelvis, chest, and least of all on the parts of the body that develop early - the head, legs. The greatest yield (4111 ± 127 kg) was obtained from Simmentals with an average duration of intrauterine development (286-296 days). At the same time, animals in which this indicator exceeded 295 days, transferred for 6 days - (the average became 289.7 ± 0.95), the weight was 2997 ± 231 kg. On animals of the Dutch breed, it was established that their productivity was directly dependent on the degree of use of feed nutrients at an early age, and the latter was inversely proportional to the duration of embryonic development. The weight of cows with an average duration of embryogenesis (266 days) was 5060 kg with a fat content in milk of 4.1%, and with its duration of 277 days - 4705 kg and 4.16%, respectively. The importance of the duration of fetal development is estimated by scientists in different ways.