REPRODUCTIVE PERFORMANCE OF FINNISH LANDRACE EWES MATED TWICE YEARLY

Abstract

The reproductive performance of a small flock of Finnish Landrace ewes in which the adult ewes were exposed to rams twice yearly, in the fall and in the spring, has been evaluated over a period of five consecutive breeding periods. Overall, 33.3% of the ewes conceived at each of the five breeding periods, and 72.2% conceived at least four times. The mean conception-to-conception interval, for all intervals of 8 mo or less, was 189.3 (range 171–237) days, and 42.6% of consecutive conceptions had occurred within 182 days. Of the 172 ewe exposures that were carried out with the adult ewes over the five consecutive breeding periods, 146 conceptions (84.9%) ensued, producing 305 lambs. The mean lambing rate over the five consecutive breeding periods was 1.77 lambs per ewe exposed, equivalent to a mean lambing rate of 3.54 lambs per ewe exposed for a 12-mo period.