GENOTYPIC ASSESSMENT OF KARAKUL EWES AFTER FURSKIN QUALITIES OF THE PROGENY
I. Buzu
Abstract
The purpose of the research consists in improving the assessment methodology and technology of the genotypic quality of the Karakul ewe furskin. Research has been done on a flock of Moldovan Corpulent Karakul sheep breed in the flock of Institute of Zootehnics and Veterinary Medicine (village of Maximovca, Anenii Noi district). It has been researched fur skin qualities of new born lambs, descendants of ewes batches of different evaluation classes: elite, class I and class II, similar after the body weight and age, inseminated with same rams. Assessment of fur skin qualities of the lambs was made at 1-2 days after birth, through evaluation, as required by evaluation instructions in force, providing the evaluation of characters value, as much after the terminology system (in words), as after the decimal point system. As a result of the evaluation, the furskin qualities of Karakul lamb at birth are expressed in evaluation class, as an integrated character. Research has shown that Moldovan Karakul ewes, inseminated with the same ram, in all other equal conditions, transmit to descendants, mainly, their furskin qualities. Thus, the elite class sheep, inseminated with same rams, have given birth to lambs of the same class (elite) in the ratio of 43,7-60,0%, first class ewes gave birth to progeny of the same class 49,0-52,3% and second class ewes gave birth to lambs of the same class with 37,91 - 52,9%. At the same time, part of the ewes does not produce progeny in accordance with the settled regularity. This depends on the genotype of ewes after furskin qualities of progeny and is carried out according to the genetic compatibility of mating partners. The presented data confirms that heredity of furskin qualities (class) at Karakul lambs is polygenic and has an intermediate character with a regression trend compared with the average of flock. The manifestation degree of furskin traits of descendant, in all equal conditions, depends on their heritability coefficient of related flock, of genetic compatibility of the parents, the prepotence degree of the rams and suitable ewes for mating. For estimating the genotype value of furskin quality at Moldovan Karakul ewes, was proposed a method of determination using the following formula: .
The formula includes the sum of the lambs-descendants phenotypes, expressed by thus ranking with scoring drives after the decimal system. Taking into account the fact that the phenotype of their own productivity reflects also, in part, hereditary potential of the animal, the genotype value of the ewes after furskin qualities, taken as a whole, can be determined by summing up the own phenotype value with the phenotypes of descendant lambs. This allows the definition of each animal's rank in the flock and deduction of the breeding nucleus with the most valuable females.
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