Herbage quality and growth rate of single and twin
lambs at foot
A.J. Litherland and M.G. Lambert
AgResearch, Grasslands Research Centre, Private Bag 11008,
Palmerston North, New Zealand
Proceedings of the New Zealand Society of Animal Production.
2000 60: 55-57
Single and twin lamb growth rates, herbage mass and quality were
monitored 3-5 times from birth to weaning on 6 farms in the southern
North Island. Lambs (n = 50-80/farm) were tagged and weighed at birth,
and ewes (n = 20-50/farm) grazing with the monitored lambs were tagged
and weighed from docking. The average live weight gain (LWG) from birth
to weaning was 273 g/d (229-311) and 220 g/d (152-279) for single and
twin lambs respectively (P<0.001). Single-pregnant ewes maintained their
weight over lactation while twin-pregnant ewes lost 41 g/d (P<0.002) and
were 4.6 kg lighter (P<0.002) at weaning. The mean herbage mass in
paddocks grazed by single or twin-pregnant ewes during lactation was
1120 and 1450 kg DM/ha respectively (P<0.001) and remained relatively
static over the lactation period. Mean herbage energy concentration
averaged 10.5 MJME/kg DM during the first two months of lactation but
had declined to 8.9 by weaning (P<0.001). In conclusion, twin lamb
growth rates on hill country are considerably lower than those of single
lambs.
Keywords: NZSAPAB;
lamb growth, single, twin, pasture quality, hill country.
Last Updated 12-07-2000
