- Trends in Ewe Productivity in the Klerefontein Selection Experiment
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Trends in Ewe Productivity in the Klerefontein Selection Experiment
G.J. Delport, G.J. Erasmus and A.O. de Lange,*
ADSRI Middelburg CP and *UOVS, Bloemfontein
The effects of different selection policies on later a Total Ewe Productivity Index (TEPI) was investigated.
The BLUP of TEPI was obtained by a multiple trait mixed model analysis utilizing canonical transformation. TEPI was defined as (3x BLUP Greasy fleece mass + BLUP total mass of lamb weaned) summed over two lambings.
The subjectively selected flock showed a significant (P<0.05) genetic increase of 0.256 per annum in TEPl. The objectively selected flock (for fleece mass) and the control flock showed non-significant increases of 0.121 and 0.159 respectively.
It is concluded that the subjective selection for body mass was responsible for the increase in TEPI. Selection on maiden performance is compatible to selection for TEPl after lambs and wool in later life has been produced.
SASAP Congress 1988