Evaluation of Duckweed (<i>Lemna minor</i>) as a feed ingredient in the finisher diets of broiler chickens

Abstract

Effects of incorporating duckweed into broiler finisher diets at proportions of zero (control), 10, 20 and 30 percent on performance and carcass composition were investigated using 160 male broilers. This study was carried out under controlled conditions in the Animal Bio-Assay laboratory in the University of Zimbabwe from April 1998 to June 1998. On day 21, birds were randomly allocated to one of the four dietary treatments. Diets were isonitrogenous, provided similar amounts of metabolisable energy (ME) and all other nutrients according to literature requirements. Birds were given ad libitum access to feed and water. After six weeks the birds were slaughtered and dressed weights and abdominal fat pad weights were recorded. Carcass samples were also analysed for dry matter, ash, crude protein, ether extractable fat, calcium and phosphorus. Increasing the proportion of duckweed in the diet was associated with a concomitant decrease in feed intake, weight gain, feed conversion efficiency, dressed and abdominal fat pad weight (P<0.05). However, responses were similar (P>0.05) in birds fed the control diet and that containing 10 percent duckweed, except for the lower (P<0.05) dressed weights obtained when birds were offered the latter. There were no differences in carcass composition among treatment groups, except that carcasses from birds fed on the 30 percent duckweed diet had significantly lower (P<0.05) levels of ether extractable fat than the remaining three groups. Results suggest that duckweed can be incorporated in broiler finisher diets to at most 10 percent level without compromising growth performance or carcass composition.

Journal of Applied Science in Southern Africa Vol.5, No.1 pp. 25-34