Abstract
Broilers were collected from 3 farms in which there was high mortality, stunting and leg weakness characteristic of a condition referred to by various names, including infectious stunting, pale bird syndrome, malabsorption syndrome and helicopter disease. Broilers were also collected from a 4th farm in which no birds showed the syndrome. Most but not all of the stunted broilers exhibited paleness, poor feather development and broken feather shafts. Most lesions and abnormalities of the internal organs were of low frequency and not correlated with stunting. Bleaching of the pancreas was found in 47% of the stunted broilers. Compared with normal-size broilers from the same farms, the stunted broilers had increased plasma protein, decreased plasma pigment, and a sometimes increased liver glycogen level. The increase in protein was the result of increased levels of .alpha., .beta.1, .gamma.1 and .gamma.2 globulins. The levels of plasma glucose, body temperature, breast muscle moisture, packed cell volume and intestinal pH were not affected in stunted broilers. No difference could be demonstrated between stunted and normal broilers in the in vitro intestinal absorption of glucose of L-methionine.