These counts, which reflect buried seed loads, will determine ragwort establishment in the short term. Ragwort establishment in the longer term will be determined by seed production under the new management regimes imposed in this trial. The ewe hoggets used in this trial gave very good ragwort control and reached 63 kg at 20 months. Care is recommended, however, if one mob of sheep is used continually in a MS regime to control tall dense ragwort, as their intake of the toxin will be much higher than in the present trial when MS sheep grazed over only short intervals. Not all sheep eat ragwort.
Research is needed to determine why some sheep avidly eat ragwort while others reject it.
Veterinary Clinical Toxicology. Massey University, New Zealand. Cameron, E., 1935. Craig, M., 1979. Serum enzyme tests for pyrrolizidine alkaloid toxicosis in cattle and horses.