Proceedings of the New Zealand Society of Animal Production.
1988, 48: 131-134
Proceedings of the New Zealand Society of Animal Production.
1988, 48: 131-134
Dosing resulted in elevated serum gamma glutamyltransferase (GGT) levels in the ewes but not the lambs. Dosing with 0.125 and 0.250 mg sporidesmin/kg live weight elevated group mean GGT levels by about 40 and 110 iu/l. Most of this increase appeared to be associated with lambing and lactation as the undosed ewes showed a similar increase. Increasing dosage of sporidesmin was associated with decreasing ewe survival (100% v 98% v 89% P<0.05), reduced lamb birth weight (4.6 v 4.5 v 4.2 kg P<0.05), docking weight (8.0 v 7.6 v 6.8 kg P<0.01), weaning weight (18.6 v 17.6 v 17.1 kg P<0.1) and lamb survival (91% v 82% v 69% P<0.05). Ewe live weight, fleece weight, lambing date and milk production were not affected by treatment.
The cost of a minor facial eczema outbreak in an autumn lambing flock is estimated from data in this trial, to be about 30% fewer kg lamb weaned per ewe pregnant plus 12% fewer ewes present at weaning. These losses are about 2 to 3 times those reported for ewes following a field challenge of sporidesmin around the time of mating. The risks of sporidesmin poisoning and lost production must be considered in managing autumn lambing systems. These results highlight the need for cost effective control programmes.
Keywords: NZSAPAB; Sporidesmin; gamma glutamyl transferase; pregnancy; live weight; wool production; survival
