Investigations into the toxicity of Echium plantagineum in sheep: 1. Field grazing experiments

A field grazing trial was undertaken to monitor the health and production of crossbred sheep grazing pasture where Echium plantagineum constituted a considerable proportion of the available forage. The trial, conducted for 19 months over successive grazing seasons, demonstrated a significant difference in production, with sheep on the E. plantagineum pasture being lighter and growing less wool compared with sheep on Echium-free pasture. No mortalities involving pyrrolizidine alkaloid poisoning were recorded in sheep grazing E. plantagineum, although there was histological evidence of moderately severe liver damage associated with high liver copper concentrations in at least one sheep following the grazing of large quantities of the plant.     

Premature farrowings caused by feeding cottonseed meal

Increasing the level of cottonseed meal (CSM) in sow diets from less than 5% to 10% increased the incidence of premature farrowings (gestation length less than 111 days) from 1.1% to 2.7% (p less than 0.001) and reduced the mean gestation length from 114.07 +/- 1.53 to 113.70 +/- 1.59 days (p less than 0.0001). Survival of piglets born prematurely was poor. After removal of CSM from the diet there was a residual effect lasting several weeks before the gestation length returned to normal. Experimental feeding of diets containing 20% and 40% CSM to small groups of sows caused significant shortening of gestation length and 3 of 26 sows fed 40% CSM farrowed prematurely. The mechanism by which CSM causes this effect has yet to be determined.     

Immunoreactive N-terminal fragment of proatrial natriuretic peptide, ANP (1–98), in plasma of healthy dogs and dogs with impaired volume regulation: a comparison with the C-terminal ANP (99–126)

Atrial natriuretic peptide (ANP) is stored in atrial myocytes as a 126 amino acid precursor molecule (ANP 1-126) and is cleaved during its release into circulation into the biologically active C-terminal ANP (99-126) and the N-terminal counterpart, ANP (1-98). While interest has focused on ANP (99-126) under physiological and pathophysiological conditions, data for the cosecreted N-terminal sequence, ANP (1-98) are generally missing. Plasma levels of the N-terminal immunoreactive peptide (N-ANP [1-98]) were measured in normal dogs, and in dogs with impaired volume regulation (congestive heart failure; chronic renal failure or Cushing's syndrome and compared with those of C-ANP (99-126). The N-ANP (1-98) concentration was 593.1 +/- 81.1 fmol ml-1 in normal subjects, which is about 60-fold higher than the C-ANP (99-126) (10.8 +/- 2.6 fmol ml-1). In patients suffering from chronic renal failure ANP (1-98) was increased to 1582 +/- 196 fmol ml-1, and in dogs with congestive heart failure to 1612 +/- 244 fmol ml-1. In contrast, Cushing's syndrome dogs showed decreased N-ANP (1-98) concentrations (351 +/- 65.9 fmol ml-1). There was a positive correlation between plasma levels of N-ANP (1-98) and C-ANP (99-126) levels (correlation coefficients: normal: r = 0.78; congestive heart failure: r = 0.76; chronic renal failure: r = 0.86; Cushing's syndrome: r = 0.57). High pressure liquid chromatographic analysis of dog plasma showed one major peak of N-terminal immunoreactivity corresponding to ANP (1-98).(ABSTRACT TRUNCATED AT 250 WORDS)     

Photosensitisation and crystal-associated cholangiohepatopathy in sheep grazing Brachiaria decumbens

Two outbreaks of photosensitivity and jaundice in sheep grazing the grass, Brachiaria decumbens. In West Java in 1983 and 1983 and 1990 are described. Aggregates of acicular clefts and crystals were present in bile canaliculi, bile ducts, Kupffer cells, hepatocytes and in kidney tubules. The number of crystals increased with the length of exposure to the plant and sheep that died had the largest accumulations. These crystalline structures have been reported before in this syndrome, but are similar to those seen in Tribulus terrestris and Panicum spp toxicities.