The effect of management strategies on the productivity of weaner sheep in north west Queensland.

Abstract

Proc. Aust. Soc. Anim. Prod. Vol. 18 THE EFFECT OF MANAGEMENT STRATEGIES ON THE PRODUCTIVITY OF WEANER SHEEP IN NORTH WEST QUEENSLAND D.H. COBON*, P.D. O'SULLIVAN** and P.T. CONNELLY* Pasture management strategies that increase weaner productivity (Stephenson et al. 1985) are of major benefit to the sheep industry, particularly in north High weaner mortality can be attributed to low protein west Queensland. content in the pastures (Rose 1972). These experiments were designed to improve pasture quality by stimulating new growth. Mixed sex weaners (5-6 months old) were used in three experiments, completed in three seasons. _ Weaners were randomly allocated to paddocks where pasture was harvested for hay (5% of area) then allowed to regrow (4 months) or spelled (4 months) (Expt 1); pre-grazed with cattle (5 weeks at 1 steer/l.5 ha) then Sheep were weighed spelled (4 months) or spelled (5 months) (Expts 2 and 3). for five weeks (Expt 1) and 12 weeks (Expts 2 and 3) after commencement of the Rumen ammonia (NH,) measurements were conducted on sixmweaners in treatments. each treatment in experiments 1 and 3 up to four weeks after commencement. Wool production was measured on midside clip patches (10 per group) (Expt 1) or from annual fleece weight (Expt 2). Table 1 Number, mean liveweight gain (ADG), rumen and survival of weaners ammonia, wool production Liveweight gain of weaners was significantly greater in harvested and pregrazed paddocks, compared to spelled paddocks. The higher liveweight gain in experiment 3 was accompanied by a higher rutnen ammonia concentration which suggests the availability of higher quality pastures. Providing soil moisture is adequate, removing the tall dry pasture appears to stimulate regrowth of new pasture of higher quality, which improves weaner growth rate but not wool production. ROSE, Mary (1972). Proc. Aust. Soc. Anim. Prod. 9:48. STEPHENSON, R-G-A., PRITCHARD, D.A., PEPPER, P.M. and CONNELLY, P-T. (1985). Aust. Rangeland J. 7:75. * ** Toorak Research Station, Julia Creek, Qld. 4823. Department of Primary Industries, Winton, Qld. 4735. 466