Sewage sludge and seaweed (Ulva sp.) as supplementary feed for chicks

Sewage sludge and a kind of seaweed, Ulva sp., were used as supplementary feed for chicks. Different diets were prepared by mixing the two supplementary feeding stuffs separately with the control diet (5%, 15%, 25% w/w). These diets were fed continuously for 35 days to chicks from the age of 53 days. No significant differences in growth rate were found between the chicks fed Ulva sp. and the control group. The sludge was inferior for feeding chicks, as shown by their lower growth rates. However, the growth rate on the lower gortion of sludge (5%) was similar to that of the control group.

The contents of crude protein, crude fat and available carbohydrate and the metabolisable energy of the supplementary feeds used in the present study were similar to those of the control diet. Although no visual gross histopathological symptoms in liver and kidney of chicks were observed, further study should be made of the potential hazard of the various heavy metals present in the sewage sludge.