Study design

The experimental diets included a control (Diet 1) in which no spent yeast was added. The other experimental diets constituted different rates of spent yeast. These were 0.05 g/kg (Diet 2), 0.10 g/kg (Diet 3) and 0.15 g/kg (Diet 4).

Day old chicks were weighed in batches of 10 for the first three weeks and the mean value assigned individually to each chick in a batch. After the third week it was possible to weigh chickens individually. Chicks were individually tagged on a leg at the start of the experiment. Each day the feed left over from the day before was measured and the daily amounts added together to allow weekly feed intake to be calculated. Deaths were recorded daily.