An epidemiological study of abomasal bloat in young lambs

Abstract

Abomasal bloat in young lambs in clinically characterized by a distension of the abdomen, especially on the right side. The significant finding at necropsy is a gas-filled abomasum. Abomasal bloat was studied over a 2-year period in 28 flocks located in Alvdal and Rendalen, two mountain valley communities in south-east Norway. The herd incidence rate varied from 0 to 20%. Abomasal bloat was most often seen 15–30 days after birth, and most cases occurred in the period just before and after the lambs were turned out to spring pasture. There was no significant difference in the incidence rate of abomasal bloatin single, twin and triplet lambs. The following factors were found to have a significant effect on the incidence rate: geographical area, type of floor, and interaction between the type of floor and the % grass silage in the roughage. Highest rates were found in flocks with built up litter floors and more than 25% silage. Substituting perforated floors for built up litter floors in 3 sheep houses reduced the incidence rate markedly. The aetiology of the disease is discussed. It is suggested that young lambs housed on built up litter with a wet consistency nibble hay contaminated with faeces. This can lead to an excessive gas-producing flora in the abomasum.