An assessment of beef and carcasses of Ukrainian meat breed bullocks belonging to different classes was carried out according to TS 46.14.09-96, that provide beef cattle division into two categories. The category "A" includes big sized animal breeds. The category "B" includes precocious ones. Young animals are divided into three classes based on body weight and/or weight of carcasses: prime, first, second. The standards for carcasses according to their quality are determined.

A slaughter performance of Ukrainian meat breed bullocks, which belong to category «A», depending on their age, is studied comprehensively. It was found, that with the age a content of adipose tissue in the fat depot tends to increase. Net increase and percentage of bones tend to reduce. But still, quantitative and qualitative characteristics of carcasses according to their weight are not full. Thereby, the purpose and objectives of the research was to develop the characteristics of the meat performance of bullocks of different classes according to their carcasses weight by TS 46.14.09-96.

Data about meat performance of Ukrainian meat breed bullocks, which are breeding at the plant "Volya" (Cherkasy region) served as a study material. From the very birth to a weaning date an offspring was kept with mothers. At the age of
8 months animals were put to the test on their own performance; it lasted until they reach the age of 20 months. After a slaughter (according to TS 46.14.09-96) animals, whose carcasses weight was more than 270 kg were classified as a prime; those of weight from 250 to 269 as the first class; from 220 to 249 kg – the second. The area of "eye muscle" of the longest back muscle (m. Longissimus dorsi) was determined in accordance with the requirements of ICAR.

Because of the high slaughter performance of young animals an evident contradiction in classifying them on live and slaughter weight is observed. There is a significant difference between slaughter performance of bullocks of different classes. The highest performances (56.9 %) show animals of the prime class. According to this characteristic they are preferential if to compare with their peers of the first and the second classes by 2.8 and 3.9 times. The length of the half-carcasses of animals of the first class is by 2.5 and 4.6 % bigger, and hip circumference by 3.7 and 9.2 % bigger than of their peers of the prime and the second classes. Bullocks of the prime class have better characteristics of hip length, but the difference between groups is insignificant.

The increase in young animals carcasses weight improves their muscling development. The highest (103.8) muscling development coefficient (excellent) K1 have animals of the prime class and it is higher than of peers of the first and the second class by 10.8 and 16.3 %. Good muscling development coefficients K2 have young animals of the first class. Bullocks of the second class have much lower basic characteristics comparing to their peers of other classes.

With the increase of the weight of animals’ carcasses the area of "eye muscle" increases, so that indicates the longest back muscle and forecasts the performance of a muscle tissue of the highest grade. The width and the depth of "eye muscle" is different for all classes, but the animals of the prime class show the highest characteristics.

The best (82.3 %) water retain ability of a meat have bullocks of the first class. The juiciness of meat depends on its ability to retain water and hold it in intramuscular fat. This is determined by area of beef and water stain. Bullocks belonging to the prime class have an area of stain bigger than animals of the first and the second class by 21.1 and 2.4 %.

A tendency of decrease of the moisture content and the increase of dry matter in the longest back muscle is traced as the class of bullocks gets lower. Water retain ability and meat boiling characteristic of animals do not differ significantly.

Thus, the data on meat performance peculiarities suggest, that the highest carcasses performance, an "eye muscle", hip length and muscling development coefficient K1 have bullocks with the weight above 270 kg. Characteristics of water retain ability and meat boiling characteristics do not diverge significantly among bullocks of different classes. The worst quantitative and qualitative characteristics have bullocks of the second class. So, it is expedient to choose bullocks of Ukrainian meat breed of the prime and the first classes for better meat performance indicators.

Key words: Ukrainian meat breed, carcasses characteristic, area of "eye musclel", technological properties of beef.