A comparison of rams from fleece weight-selected and randomly bred Romney flocks for intake, wool growth and feed utilisation

L.A. McClelland, H.T. Blair, G.A. Wickham and I.M. Brookes

Animal Science Department, Massey University, Palmerston North

Proceedings of the New Zealand Society of Animal Production. 1986, 46: 215-218

Two pen-feeding experiments were conducted on Romney rams from fleece weight-selected (FW) and control (C) flocks. In experiment 1, 12 yearling rams from each group were fed cut ryegrass/clover pasture ad libitum for 6 weeks. In experiment 2, 9 ram hoggets from each group were fed lucerne based diets in 3 periods (P1, P2, P3). Individual feeding in P1 was 1 kg/d protein-extracted lucerne; P2, 1 kg/d protein- extracted lucerne plus 0, 30 or 60 g/d formaldehyde-protected casein; P3, 1.4 kg/d chopped lucerne.

No differences in intake or liveweight, and no consistent trends in dry matter digestibility were found. FW rams had consistently higher greasy wool growth, this difference increasing with higher intakes and casein feeding. Between rams, the regression of wool growth on intake was positive for FW rams and negative or near zero for C rams. FW rams had greater live-weight gain than C rams when fed chopped lucerne. Differences in wool growth between FW and C rams could not be directly attributed to intake.

Keywords: NZSAPAB; Romney rams; fleece weight-selection; wool growth; feed intake; feed utilisation

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Last Updated 18-03-1997