The research aims to study the meat productivity of Kazakh and Tuva horses in a comparative age aspect. The objects of the research are the local populations of horses of the Kazakh breed in the Republic of Kazakhstan and the Tuva native breed in the Republic of Tyva of the Russian Federation. All animals were clinically healthy. It has been established that in Kazakh foals, the pre-slaughter weight at 6 months of age was 195.5 kg, at 12 months 268.6 kg, 18 months 319.0 kg, 24 months 327.5 kg, 30 months 388.3 kg, and the Tuva breed 174-210-290-310 and 342 kg, respectively. The relative weight of the organs of the digestive tract from the pre-slaughter weight of animals in Kazakh colts of 6-month age is minimal, taking 6.4%, at 12 months 7.09%, 18 months 6.72%, 24 months 6.76% and 30 months 5.85%. The research results showed that in Kazakh colts, although the internal vital organs grow and develop in absolute terms with the age of the animals, in a comparative aspect with the preslaughter live weight, their percentage decreases. Thus, the liver of a 6-month old Kazakh colt weighs 4.0 kg, which is 2.0% of the preslaughter weight, at 12 months 5.5 kg (2.1%), at 18 months 5.7 kg (1.81%), at 24 months 5.8 kg (1.79%), and 30 months 5.8 kg (1.52%). A similar picture is observed for the lungs, heart, and kidneys. It was found that in Tuva colts from 6 to 24 months of age, the coefficient of meatiness varied from 6.0 to 6.3.