Correlating stock and pasture production in Northland

P.J. Rumball

Grasslands Division, DSIR, Kaikohe

Proceedings of the New Zealand Society of Animal Production. 1980, 40: 85-91

The pattern of feed availability and inefficiencies in feed transfer are considered prime causes of poor stock performance in Northland. In separate trials, a normal spring lambing pattern was compared with winter/spring lambing and with autumn/spring lambing. Two pasture types were also compared - mainly ryegrass, and mainly kikuyu/ryegrass.

Spreading the peak of feed demand backward into winter and forward into late spring lessened ewe liveweight losses and increased lamb weight gain during lactation. Increasing the autumn feed demand by 40% for 12 weeks and delaying spring lambing by 2 weeks reduced wool yield but had no significant effects on ewe or lamb liveweight change during spring.

Poor utilization of feed carried forward into spring and relatively slow pasture growth lead to consistent undernutrition of ewes early in lactation. The transfer of some feed demand from spring to winter or autumn will partly alleviate this. On pasture containing kikuyu, it would be better to lamb later than on ryegrass-dominant pasture and to increase utilization in late summer/autumn.

Keywords: NZSAPAB;

Last Updated 12-09-1998