I. Buzu


DETERMINING THE BREEDING VALUE OF KARAKUL EWES AFTER COMPLEX SELECTION INDEX

I. Buzu

Abstract
    The aim of this work was the elaboration a method for estimating the breeding value of Karakul ewes by building and applying complex selection indices. The research was conducted on Moldavian Karakul sheep from flock of National Institute of Animal Husbandry and Veterinary Medicine from Maximovca village, Anenii Noi district, Republic of Moldova. In the paper have been examined construction methodology complex selection index of ewes from Moldavian Karakul race. It was found that, previous, for construction complex selection index has been reduced the number of characters and skins traits of lambs at the evaluation marks from 29 to 7, and the latter have been synthesized into a single character - class of lamb expressed in points after the decimal system. Have been identified 3 basic morph-productive characters (the descendents skins quality, the own body weight, the ewe milk production) and followed by the selection of sheep. It was determined the economic value (share) of each selection character in the total income from one animal per year. For each selection character partly was calculated phenotype aggregate coefficient (Cfa) which allows expression of the value of each character in single units of measure, using the following formula:
    Cfa=Pve/Ms (1)
    where, Cfa - coeficient of phenotype aggregat;
    Pve - share economic value of the selection character;
    Ms - phenotypic size standards of selection character
    Having the coefficients of phenotype aggregate for each selected character apart, we have built complex selection index formula of ewe, after following formula:
    Ics = (Mfp • Cfap) + (Mfmc• Cfamc) + (Mfpl • Cfapl) (2)
    where, Ics - complex selection indices of ewe;
    Mfp - phenotypic size of descendents skins quality;
    Cfap - coefficient of phenotype aggregate of skins character;
    Mfmc - phenotypic size of own body weght of ewes;
    Cfamc - coefficient of phenotype aggregate of body weght character;
    Mfpl - phenotypic size of ewes milk production;
    Cfapl - coeficient of phenotype aggregate of milk production;

Key words: Selection complex index, ewes, Karakul