摘要：The article is devoted to the assessment of the efficiency of se-lection of the initial lines of the Plymouth Rock breed of the domestic meat cross “Smena 9”. It was found that breeding of meat chickens of lines CM7 and CM9 (from 2016 to 2020) resulted in an increase in the live weight of the young, fleshing of the chest and legs at 35 days of age, the feed conver-sion for both cockerels and hens by 8.8-10.0%; 0.9-1.9% and 1.0-1.9%; 1.2-1.8%. In 2020, all juveniles of the paternal line CM7 at one day of age were the carriers of the marker gene K (100%), the maternal line Cm9 - the carriers of the marker gene K (100%). The accuracy of sexing of the maternal parental form CM79 is 99.7%. From one parental pair of the Smena 9 cross, 307.6 kg of meat was obtained, which is 14.2% higher than in the previous cross. The average daily gain of the final hybrid of the cross “Smen. 66 kg/kg; a 9” grown in the production conditions of the SGC “Smena” was 63.5 g; feed costs were at 1.66 kg/kg; preservation rate - 98.8%; the output of the pectoral muscles and the slaughter yield - 23.5 and 73.1% (against 56.3 and 71.4%). The bird of the cross “Smena 9” is competitive.
