Phenotypic and genetic aspects of production in the Dohne Merino. III The influence of age of the ewe on reproductive performanc

Author: A.J. Fourie and H.J. Heydenrych
Year: 1983
Issue: 3
Volume: 13
Page: 164 - 166

To determine the influence of age of ewe on reproductive performance and the age specific death rate in the Dohne Merino, data from 1 310 individual lambings accumulated between 1975 and 1980, were used. The reproductive performance of the Dohne Merino flock increased up to the age of 5 years after which it remained relatively constant to the age of 7 years and then declined. The maximum number of lambs born (0,98) and weaned (0,88) per ewe mated, occurred at 6 years of age. The same tendency was observed in respect of lambs born (1,12) and weaned (1,00) per ewe lambed. The maximum number of ewes lambed per ewe mated (0,89) also occurred at this age. Mortality in the ewe flock increased with age but increased steeply after the age of 7 years. A flock structure including 5 to 6 age groups (ewes of 6 to 7 years of age) will thus ensure an optimum reproduction potential in the flock.


Keywords: Dohne Merino, ewe age, reproductive performance
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