Korchagina O., Ivanova N., Gajsin R.

Influence of breeding worth of parents on increase of milk yields and milk quality of cows of black-motley and Holmogorsky breed

Reserves of increase of milk yields and exit of butterfat and protein at the expense of use of bulls and mothers-cows with high breeding worth are shown in dairy cattle selection. Parental index of a bull in a greater degree influences growth of milk yield of cows-daughters, and a parental index of a cow – exit of butterfat and protein in milk. Selection of parental pairs, taking into account parental indexes, gives the chance to fix available and to form new valuable qualities of herds and breeds.

Keywords: SELECTION of PAIRS of BULLS and COWS, RANK ESTIMATION of BULLS, MILK YIELD, EXIT of MILK BUTTERFAT and PROTEIN, BLACK-MOTLEY and HOLMOGORSKY BREEDS of CATTLE, PARENTAL INDEX of a COW, PARENTAL INDEX of a BULL