the addition of blood, a method of breeding agricultural animals; used for the improvement or correction of certain qualities of a valuable breed without radical change in its principal properties. The method consists essentially in the skillful selection of the improving breed and the one-time use of its sires with the dams of the breed to be improved. The best crossbred sires of the first generation are subsequently mated with the dams of the breed to be improved, and the crossbed dams with the best sires of the breed to be improved. The progeny of this crossbreeding are raised “within themselves” or are again crossbred with animals of the breed to be improved, with only the next generation raised “within itself,” using strict selection of animals. The meat quality of several dairy breeds of cattle in the USSR and abroad has been improved by crossbreeding with meat breeds. Many breeds of light harness horses have been improved by crossbreeding with eastern horses, purebred saddle horses, and others. Induced crossbreeding has also been used to increase the fertility of sheep. It is very little used in hog and poultry raising.
O. A. IVANOVA