Influence of the year on the fecundity of Ile de France sheep

Nikola Metodiev

Abstract: The aim of the present study was to evaluate the influence of the year (year of birth and respectively,
the years of realization of the births) on the biological fertility of the first and second lambing
of sheep of the Ile de France breed. The study was conducted with 171 purebred ewes reared in IAS
– Kostinbrod in the period 2008–2017. The study included only sheep with two consecutive lambing
(first and second) in two consecutive calendar years. The years had a significant effect on the variation
of fecundity, both on the first lambing (F = 2.117, P < 0.05) and on the second lambing (F = 2.562, P
< 0.01). The fecundity of the first lambing for the separate years varied widely – the highest fecundity
had those born in 2013 – 175.00%, and the lowest – those born in 2015 – 117.65%. The same wide
variation was observed again in the second lambing – the highest fertility had those born in 2015 –
182.35%, and the lowest – those born in 2017 – 110.00%.

Keywords: effect; fecundity; Ile de France; sheep; year

Date published: 2021-12-22