Published online by Cambridge University Press: 27 March 2009
By alternately joining the rams with the ewes for two months and separating them for the following two months' period 63% of the lambings took place at eight-month intervals.
The conception rate was 85% for October–November breedings, 58 for February–March and 43 for June–July. The twinning rates for corresponding periods were 38, 8 and 7. The length of the post-partum interval had no significant influence on the conception rate.
For October–November breeding 63% of the lambings occurred between 150 and 169 days after the introduction of the rams, whereas the corresponding figures for February–March and June–July were 47 and 14, respectively.
The yearly lambing percentage was 119 as compared to 86 for a previous period from 1955 to 1963, when the rams were kept with the flock throughout the year.