Med. Weter. 77 (03), 149-153, 2021

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Index selection of Kazakh karakul sur-type sheep with platinum shades
Aim of the study: Karakul sheep farming is one of the effective subsectors of animal breeding in the southwestern region of Kazakhstan. Sheep coloring is a result of genetic factors. Breeding can provide farmers with offspring of the desired color through the selection of parental couples. Materials: This research introduces an index method for breeding sur-type sheep with the proportion of underfur fibers under 25%. Such a proportion of underfur fibers provides a 15.25% deeper color within the breed at the 25.3% higher chance of getting platinum shades. Methods: Platinum coloring in sheep makes them less piebald. The inheritance index is quite stable and is within 55.66-65.66%. In the breeding flock, the initial proportion of sur-type lambs which could be used in coat making (elite class) was up to 8.72%. The analysis of platinum color heritability by Kazakh sur-type karakul sheep shows that this color is inherited as a dominant one in the line breeding. The share of sur-type sheep with platinum shades was between 85.85% and 87.27%. Results: The difference in the inherited trait between the groups of sheep selected according to the proportion of underfur fibers was insignificant, 0.99-1.42% (P > 0.05). The stabilizing selection introduced into the theory of line breeding of Kazakh sur-type sheep allowed optimizing the variability of selected features to the level of desired parameters. The authors have proposed the index selection method for sur-type sheep breeding that can be applied to improve the Atyrau sheep flock, to increase their genetic potential, and to apply various line breeding levels to accelerate the breeding process. Conclusions: The originally designed method for improving breeding indexes will be useful when setting optimal breeding goals (fur color and quality) and assessing genetic parameters of a certain sheep flock. The study was approved by the Ethics Committee attached to the Far Eastern State Agrarian University (Protocol No. 5 of 25 May 2010).
Keywords: breeding, index selection method, fibers, selection