For effective management of animal breeding, complete, high-quality and reliable information about an individual animal, about the population as a whole, is required. For breeding work, it is necessary to select breeding bulls, the offspring of which have high productivity. The selection of ancestors and offspring of bulls makes it possible to consolidate or consolidate these traits. The aim of the research is to improve the methodology for beef cattlegenetic evaluation. Material and methodology. Beef cattle genetic evaluation implemented by BLUP (Best Linear Unbiased Prediction). Mixed linear biometric models (AM / MME) were built for each assessed productive trait: Birth Weight, Weaning Weight, Milking at Calf Weaning, Yearling Weight. 74,868 animals of the Hereford breed. Percentages describe 5% and 10% share distributions of index values. The EPD values of live weight at birth in 90% of cases lie in the range from “-8.76” to “+18.21”; for live weight at weaning in the range from “-35.73” to “+42.83”; for live weight per year from “-51.45” to “+90.18”. The best and lowest EPD values are in 10% edge intervals relative to the entire set of calculated estimates. The proportional distribution of EPD accuracy in 2020 for the productive indicators of animals born in the period 2014–2020 of the Hereford breed have zero values up to 10%. The smaller number of fractions of non-zero values of the CPI accuracy indicates a more complete and qualitative filling of the database with productive indicators of live masses in recent years. In Kazakhstan, a method for calculating EPD by the BLUP AM method was developed with the construction of a genetic model of an animal and EPDs were calculated according to 5 productive indicators: live weights at birth, at weaning, at 12 months. age, adult animal (age 5 years) and milk production of cows.

Improving beef quality is important task for livestock in Kazakhstan. Almost all indicators characterizing the quality of carcasses and beef are evaluated after slaughter. Their use in breeding is limited (Legoshin G.P. 2010). For lifetime assessment of carcasses in pedigree and slaughter cattle, Aloka 500B, EXAGO, EVO ultrasonographs are used, using which there is a high coincidence of the lifetime forecast of muscular development over the eye muscle area with the indicator in carcasses after slaughter of animals (Bisembaev A.T. 2019). A high correlation of prognosis of ribeye area with live weight of animals was noted (Lisitsyn A.B. 2010). The aim of the project is to study the effectiveness of in vivo determination of meat quality using an ultrasonic scanning device. Tasks: to determine the ribeye area, the fat of the cattle using an EXAGO ultrasonograph; compare the ribeye area, the fat of the slaughter cattle, determined using an EXAGO ultrasonograph and measured on the carcass after slaughter. The studies were carried out on pedigree bull-calves of the Kazakh white head (85 animals), Auliekol (101 animals) breeds aged 14–15 months and on the feeding stock (6 animals) with a live weight of more than 943 lb. The ribeye area, the fat were obtained: Kazakh white head had 23.2 sq.in and 0.10 in, Auliekol – 20.4 sq.in and 0.09 in. The animals studied after slaughter yielded full-bodied carcasses, while the slaughter yield averaged 56.3%. The correlation between live weight level and ribeye was r=0.97. The coincidence of ribeye, measured by an ultrasonograph with a post-mortem measurement averaging 93.8%. The introduction of ultrasound methods for determining beef productivity in beef industry will allow livestock husbandry to become cost-effective and improve the beef quality. The results of ultrasound images for the carcass traits will be applied in selection and breeding work.