Study on the possibilities for biological fertility increasing in Karnobat finefleece sheep

Margarit Iliev, Genoveva Staykova, Todor Tsonev

Abstract: Subject of the study were 291 sheep from the Karnobat fine-fleece breed from the herd of the Institute
of Agriculture – Karnobat, born during the period 2008–2014. The aim of the study was to
investigate the possibilities of increasing the fertility of fine-fleece sheep without changing the type
and productivity direction of the breed. Productive traits were controlled in accordance with the Productive
Trait Control Guidelines (2003, 2008) of the Association for breeding of fine-fleece sheep
in Bulgaria. 679 individual observations of biological fertility from the first to the fourth lambings
were recorded. Data were processed using the variational statistics method using Microsoft Excel
2007 computer software. It was established that twin Karnobat fine-fleece sheep and those with twinparents
demonstrated the highest fertility during their lifetime – 143%, with average fertility for the
herd – 128%. It was established that chosen animals, twins and those who gave birth to twins at first
lambing have from 146% to 153% biological fertility from first to forth lambing. The percentage of
sheep that gave birth to singles and those who were born as singles was high – 54.63%. Sheep born
as twins surpass in twinning intensity singles with 3.31–8.46% during the period of three consecutive
lambings.

Keywords: fertility; Karnobat fine-fleece sheep; singles; twins; type of birth

Date published: 2020-10-09