A case of onion poisoning in a cow.
Abstract Extract There are recorded cases (Cheeke and Schull, 1985) of onion poisoning in cattle and horses that have eaten onions, Allium cepa, but none in New Zealand (Connor, 1977). In this country pigs (Anon, 1978) and a dog (Smith and Ellison, 1986) have been reported as having been poisoned by eating onions. This letter reports a case of poisoning by that plant.
Heinz body anaemia associated with onion (Allium cepa) toxicosis in a flock of sheep
Onion (Allium cepa) toxicosis was diagnosed in a flock of local breed sheep, which had grazed daily on onion fields for 1 month. Two ewes died, four aborted and many showed clinical signs of toxicosis including pale mucous membranes, weakness and poor appetite. Haematology of 12 ewes revealed low PCV, erythrocyte number and haemoglobin, Heinz bodies in erythrocytes, polychromasia and mild leukocytosis. In those animals that died, there was haemoglobinuric nephrosis with haemosiderin deposition in tubular cells and centrilobular necrosis of liver. Onion feeding was discontinued and haematinics were used for treatment of the affected animals.
Germination ecology of Central Asian Stipa spp: differences among species, seed provenances, and the importance of field studies
Stipa-species are wide-spread in Central Asia, but sexual reproduction in the dry steppes is rare. To facilitate conservation and restoration of these important rangelands, we studied germination characteristics of three common Mongolian Stipa-species under field- and lab conditions. Seeds of Stipa krylovii, Stipa gobica and Stipa glareosa were sown at the study site in Southern Mongolia over two consecutive years during which period tests were carried out to ascertain whether competition or herbivory are the main constraints of seedling establishment. In addition, we tested germination and seed viability in the laboratory under two different temperature regimes (20/10°C and 8/4°C), as well as the effect of cold-stratification. The lab experiments also included S. krylovii seeds originating from three climatically different provenances. None of the three Stipa-species seedlings emerged during the first 2 years of the field study. However, after an unusually intense rain event in the third year, 3% of S. krylovii, 0.6% of S. glareosa and 0.1% of S. gobica seeds germinated in the study plots. The factors ‘sowing-year’ and ‘vegetation’ significantly affected seedling emergence, whereas grazing had no effect at all. Under laboratory conditions a high percentage of viable seeds of S. gobica and S. glareosa germinated at both incubation temperatures, and cold-stratification had no effect on germination or viability. Germination of S. krylovii seeds required warmer temperatures and cold-stratification had a positive effect. Such evidence for dormancy was more pronounced in seeds from the moister, northern provenances. Germination of Stipa-species in the field is rare and only possible under exceptionally moist conditions. Conservation should thus concentrate on steppe conservation rather than on restoration. Where artificial reseeding is necessary, differences among species and also among different seed provenances should be taken into account.