The purpose of the study is improving the efficiency of breeding work in selection of cows by live weight, body measurements with mandatory consideration of animal condition score. The degree and nature of relationship be-tween live weight and body measurements of beef cows with condition score, regression coefficient were calculat-ed. The research was carried out on beef Hereford and Kazakh white-headed cows. A high positive relationship between live weight, body measurements and the condition score of cows was established. The regression coeffi-cient showed that change in finish by 1 point increases the live weight of Hereford cows of the first group by 46.3 kg, the second – by 44.2 kg, and the third – by 42.1 kg. The cows of the second group have the largest bulk, they signif-icantly exceeded the Hereford and Kazakh white-headed cows of the first and third groups by this indicator. The difference was 51.2 and 45.9 kg, respectively, the coefficients of variability – varied between 4.1 to 9.2%. Hereford Cows of the second group were superior in heart girth (with a difference of 4 cm) to cows of the first group and 10.6 cm to cows of the third group. The coefficients of variability ranged within 12.9 to 27.0 %. In terms to heart girth (by 1.05 and 0.95 cm) and chest depth (by 8.9 and 2.9 cm), the cows of the second group were superior to the cows of the first and the third groups, respectively (the difference is not reliable). The variation coefficients ranged within 10.3 to 15.7% for heart girth and from 13.0 to 16.7% for chest depth.

The purpose of the research is to increase the economic efficiency of beef production by the system of cow – calf by adjusting the feeding taking into account the point assessment of fatness of meat cows. For the effective production of beef is not enough to have highly productive animals and high quality feed. It is necessary to organize their rational use of feed. In technological groups animals have different live weight, and norms of feeding of meat cattle are calculated, generally, depending on live weight of animals. This is the wrong approach, because in the group (in the herd) animals can have the same living mass and have different energy requirements depending on the state of fatness. Adjusting the level of feeding depending on the fatness of animals will save expensive feed, as in the structure of the cost of beef a large share of the cost falls on feed (about 60%). In the course of the research, a high positive relationship between the live mass and the point assessment of the cows fatness (r=0.93 for Hereford and r= 0.95 for the Kazakh white-headed breed) was established, which allowed to determine the regression coefficients between the features. It is found that increasing body condition by 1 point increases the live weight of Hereford cattle 40.4 kg and in cows of Kazakh white-headed breed of 48.1 kg. This allowed us to determine the required changes in the feeding level for 90-100 days prior to calving to increase for cows with a body condition score of 1 by 3.02; 2 points – 2.67 to 3.02; 3 points on 1.70-2.55; 4 points at 1.32-1.70; 5-6 points to 0.85-0.91 EKE, for cows with a body condition score of 8 to reduce the level of feeding of 0.47-0.85 and EKE with fatness 9 points lower on 0,85-1,70 ECE. Thus, studies show that the organization of feeding depending on the condition, is a necessary tool for achieving economic efficiency of beef production on the system cow-calf.

A comparative assessment of the reproductive qualities of beef-cows of the Hereford and Kazakh white-headed breeds is given, depending on the Body Condition Scoring. In the scientific and economic experiment in three farms on 3 groups of cows of two breeds, the influence of Body Condition Scoring on the reproductive qualities of cows was studied. It was found that cows with a Body Condition Scoring of 6 points have a significantly shorter service period (by 10-13 days) and the interval between calving (by 6-9 days), with an increase in the duration of pregnancy by 2-4 days, compared with cows with a score of 3 points. The calf crop per 100 cows, in groups with 6 Body Condition Scoring points, was higher than in groups with 3 Body Condition Scoring points by 9.2, 8.3 and 5.1%.