Diarrhoea in Merino ewes during winter: association with trichostrongylid larvae

SUMMARY A study on 3 farms, each having a preventive strategy for the control of nematode infections, determined the risk factors associated with diarrhoea among Merino ewes in winter. Comparisons were made among groups of mated and unmated ewes with and without treatment with controlled-release capsules containing albendazole. Diarrhoea was assessed from the accumulations of faeces around the breech (dag score) and related to worm egg counts, total worm counts and histopathological findings. The overall prevalence of severe dag in ewes not treated with a capsule was 26% (221/844). In comparison, only 2.7% of treated ewes had severe dag. The adjusted odds ratio on each farm indicated that untreated ewes were between 12 and 16 times more likely to be affected with severe dag than ewes treated with a capsule. The effect of lactation was significant on only one farm whereas initial body weight had no significant effect. There was no significant association between worm egg counts and the occurrence of severe dag. There were significantly more eosinophils in the small intestine of ewes affected with severe dag compared with unaffected ewes. There were no significant differences in mast cell and globule leucocyte numbers between affected and unaffected ewes. This study provides strong evidence that the main cause of diarrhoea among Merino ewes grazing winter and early spring pastures is the ingestion of trichostrongylid larvae even by sheep that have a well-developed protective immune response to these parasites. New strategies for the control of nematode infections are needed to prevent diarrhoea and dag formation in adult sheep.     

THE SOLUBILITY OF PHOSPHATE IN A CALCAREOUS SOIL

The concept of chemical potentials was used to study the solubility of phosphate in a calcareous soil when equilibrium was approached by precipitation. By comparison with results obtained by dissolution of soil phosphate it was demonstrated that precipitation resulted in a considerably greater solubility than did dissolution. The relationship between the monocalcium phosphate potential and lime potential could be reconciled with the presence of hydroxyapatite in the soil. Ion activity products near to those of pure hydroxyapatite in the presence of calcium carbonate were also obtained.     

Johne's disease in alpacas (Lama pacos) in Australia

SUMMARY: Johne's disease was diagnosed in 10 alpacas ( Lama pacos ) in Australia between February 1993 and May 1994. Eight of the animals were between 12 and 24 months of age, one was a 6-year-old female, and one was a 4-year-old male. Five, including the 6-year-old and the 4-year-old alpacas, showed weight loss and diarrhoea before death or slaughter. The other cases showed no clinical signs of Johne's disease but 4 gave a positive result on faecal culture and one gave a positive result on testing with the caprine ACID assay and had acid-fast organisms in its faeces. At necropsy, all cases had grossly enlarged mesenteric lymph nodes. Johne's disease was diagnosed after histological examination of the lymph nodes with conventional culture and polymerase chain reaction testing of tissue samples. This report outlines the clinical, epidemiological, and pathological findings in these cases.     

ANALYTISCHE UNTERSUCHUNGEN VON TRIAZ1N-HERBIZIDEN

Zusammenfassung. Die vorliegende Arbeit beschreibt die analytische Reinheits-prüfung einer Auswahl von Triazin-Herbiziden am Beispiel von Atrazin, Atraton und Prometryn mit Hilfe der Dünnschicht- und der Gas-Chromalographie.
Investigations on the analysis of triazine herbicides     

EVIDENCE OF DICALCIUM PHOSPHATE PRECIPITATION IN A CALCAREOUS SOIL

The‘precipitated-calcium/precipitated-phosphorus’ mole ratio approached a limiting value of 1 as the amount of phosphate, added to a suspension of calcareous soil in 0·01m CaC1₂, was increased, indicating the precipitation of dicalcium phosphate. The phosphate and lime potentials provided further evidence that dicalcium phosphate was present at high rates of phosphate addition.