Use of ultrasonography to detect calcifications in cattle and sheep fed Trisetum flavescens silage.

Abstract

Twelve cows (mean age 6.4 years) and eight sheep (mean age 0.8 years) were fed silage containing 70 to 90 per cent vitamin D3-effective Trisetum flavescens for a period of 14 weeks. At the beginning and the end of this period, the animals were examined and their kidneys, abdominal aortas and heart valves were examined by ultrasonography; the animals were then slaughtered and these organs were examined histologically, and the specificity and sensitivity of the ultrasonography were calculated. After the feeding period, all the cows had a decreased body temperature and all but one had raised hair, movement disorders and difficulty in rising and lying down. Ultrasonography of the abdominal aorta had a specificity of 90 per cent and a sensitivity of 75 per cent, and ultrasonography of the heart valves had a specificity of 100 per cent and a sensitivity of 50 per cent. In the sheep, cardiac arrythmia was the only pathological finding at the end of the feeding period, and the ultrasonographic examination of the kidneys had a specificity and sensitivity of 100 per cent.