STILLBIRTH PERINATAL WEAK CALF SYNDROME - PRELIMINARY PATHOLOGICAL, MICROBIOLOGICAL AND BIOCHEMICAL FINDINGS

Microbiological, biochemical and pathological data collected from 293 calves which were either stillborn, or born alive and either failed to breathe or failed to breathe for more than about 10 minutes are prese nted. No bacteria were recovered from 96 of the calves (32.7 per cent) , and bacteria which were considered significant were isolated from on ly four (1.4 per cent). Evidence of leptospiral infection was found in 75 calves (25.5 per cent). Of 64 calves examined for bovine virus dia rrhoea (BVD) and infectious bovine rhinotracheitis (IBR) antigens, two were positive for BVD virus and none for IBR virus. The mean (+/- sd) liver vitamin E and kidney selenium concentrations, determined in 148 of the calves, were 2.0 +/- 0.76-mu-g/g wet matter and 0.47 +/- 0.17- mu-g/g wet matter, respectively. The thyroid iodine concentration in 1 5 of 71 calves (21 per cent) was less than 300-mu-g/g wet matter and t he mean (+/- sd) thyroid weight of 266 of the calves was 18.5 +/- 11.6 g. Evidence of severe trauma was found in 19 of the calves (6.5 per c ent). Histological findings included thyroid epithelial hyperplasia, h epatic haemosiderosis, erythrophagocytosis in the spleen, perivascular haemorrhage in brain and adrenal glands, and accumulation of leucocyt es in blood vessels.