INFLUENCE OF SOME FACTORS ON THE FERTILIZATION ABILITIES OF SHEEP FROM THE NORTH-EAST BULGARIAN FINE FLEECE BREED-SHUMEN TYPE

Georgi Anev

Abstract: The study was carried out with the aim to analyze the fertilization abilities of sheep from the North-East
Bulgarian Fine Fleece breed-Shumen type, taking into consideration the following factors: age of sheep,
cross-breeding and production year.
It was obtained that the factor "production year" exerted a statistically significant influence (P<0.001) on
the fertilizastion abilities of the sheep. The cross-breeding had a statistically significant effect on the studied
trait too (P<0.05), but the influence of the sheep age was not mathematically demonstrated.
An average of 1.542 inseminations per sheep were carried out, which aimed the fertilization of the
analyzed population. The highest level of fertilization was observed at the purebred sheep from the North-
East Bulgarian Fine Fleece Breed-Shumen Type (1.412 inseminations) in comparison with the ones crossbred
with Australian Merino (1.629 inseminations) and Booroola (1.583 inseminations).
It was found that for the fertilization of the 2-year-old sheep the smallest number of inseminations were
done. The number of inseminations necessary for the fertilization of the 4-year-old and older sheep was
biggest.
It was observed that 25.72% of the sheep which had been inseminated during the days with high daily
temperatures were not fertilized. The nonfertilized sheep for the whole period of insemination were 21.72%.

Keywords: age; cross-breeding; fertilization abilities; sheep; the North-East Bulgarian Fine Fleece Breed-Shumen Type

Date published: 2022-08-12