Effects of shearing and herbage allowance on the intake, live weight gain and wool growth of Romney ewe hoggets in spring/summer

H. Hawker, S.F. Crosbie, M. Barber, R.N. Andrews

Invermay Agricultural Centre, Ministry of Agriculture and Fisheries, Mosgiel

Proceedings of the New Zealand Society of Animal Production. 1985, 45: 141-146

The design was a 2 x 3 x 2 factorial, i.e. shorn v woolly hoggets (shorn at 4, 12 and 17 months of age v shorn at 4 and 17 months) x 3 herbage allowances (1.6, 3.2 or 4.8 kg total DM/hogget/d) x 2 replicates x 2 years. The 12 mobs, each comprising 15 hoggets, were shifted twice weekly for 18 weeks, with residual DM measured and intakes estimated at each shift. Live-weight gain (LWG) and wool growth were measured every 6 weeks from early October until mid February.

There were no significant differences between the shorn and woolly hoggets in residual DM (and therefore in utilisation and intake) or in LWG. The shorn hoggets grew 1 g/d more clean wool during spring-summer, i.e. a total advantage of 0.2 kg greasy. LWG and wool growth increased curvilinearly with allowance. LWG's were greatest in October-November, while wool growth was greatest in January-February.

Five shorn and 4 woolly hoggets were penned outdoors in close proximity to the grazing experiment and fed a pelleted diet ad lib. for the first 6 weeks after shearing in early October. Relative to the woolly hoggets the short hoggets ate 20% less in week 1, the same amount in week 2, and increasingly more from weeks 3 to 6 (30% difference in week 6).

The results indicate that shearing in spring does not lead to significantly higher feed intakes nor to greater LWG's, although it does results in a modest increase in wool growth.

Keywords: NZSAPAB; Sheep; shearing; herbage allowance; intake; live-weight gain; wool growth