Abstract

Industry Coopworths, industry Perendales and closed lines of Romneys intensely selected for (HFR) or against (LFR) twinning, were raised in individual farmlets with ewe stocking rates of 26 (H), 21 (M) and 16 (L) ewes/ha. Lambs were slaughtered at 16, 20 and 24 weeks of age. The correlated response to selection for twinning was decreased fat depth at equal ewe stocking rates and birth-rearing status. HFR compared to LFR also increased fat depth less when weight was increased by a reduction in stocking rate. Perendales compared to Coopworths had less fat depth and increased fat depth less, when weight was increased by a reduction in stocking rate. The results suggest that fatter breeds will be comparatively leaner at high stocking rates.

RA, Field

Proceedings of the New Zealand Society of Animal Production, Volume 44, , 209-210, 1984