The object of inquiries: pure- bred and crossbred heifers and calves of Golshtin and black - variegated breeds.
The aim of the work: the study of the growth and development, meat and milk productivity and also some biological peculiarities of Goldstein, black -variegated breeds and their crossbreeds under a sharp-continental conditions of South zone of Uzbekistan.
Methods of inquiries: zootechnical, biological and economical
Obtained results and their novelty: for the first time in the researches there was revealed the genetic potential of pure - breed Goldstein, black-variegated cattle? their crossbreds according to milk and meat productivity under conditions of hot climate. Purebred young cavs of Goldstein breed exceeded their analogues of black- variegated and crossbred ones on yield of milk during the first 90 days of lactation, correspondingly 175,5 and 100,5 kg. Crossbred calves while slaughtering at the age of 18 and 21 months gave to 16,6 and 5,1; 21,1 and 7,9 kg more of fresh killed meat, than of their age of IV and V groups correspondingly.
Practical significance: increasing the production of meat and milk under conditions of hot climate of Surkhandarya valley, pure-bred rearing of Golshtin and black-variegated breeds and their crossing between each other has a great practical significance.
The degree of inculcation and economic effectiveness: The results of researches where inculcated into the herds of cattle on a farm “Chjrvador” of Kumkurgan district of Surkhandarya region. As a result of inculcation in average from one cow of Golshtin breed and from realization of one bull-calf (at the age of 18 and 21 month) there was obtained 181,0-252,8; 366,4-447,4 and 446,8-549,5 thousand sums of pure income, and the norm of profitableness comprised accordingly 46,7-64,1; 38,4-46,6 and 36,6-44.7%
The sphere of usage: all the categories of cattle-breeding farms, where there arc reared Golshtin and black- variegated breeds of cattle.
