This experiment was performed to asses response of muscovy ducklings (0-
13 weeks of age) to low protein diets supplemented with lysine and methionine. The
corn - soybean meal based experimental diets contained two levels of crude protein
were supplemented with lysine and methionine .The influnce of supplemental amino
acids was studied within each protein level. The results showed that Muscovy ducklings received low protein(20%) diet
with high lysine (1.20%) and 0.83% methionine+ cystine, had significantly (P< 0.05)
the highest value of average live body weight (876.60 g) during the starting period (0-
4 w.k). However, during the finishing and the total period ducklings fed on diet
contained high protein diet with low lysine and low methionine+cystine, had a highly
significant (P < 0.01) increase in body weight, weight gain and improved the feed
conversion values. Higher percentage of feather, giblets were recorded in group fed
on a diet contained low protein with low lysine and high methionine+cystine%.
However, higher percentage of carcass (72.41) was recorded for group fed high
protein with low lysine and high methionine+cystine%. The lowest feed cost/kg. gain
was (62.50%) recorded by group fed high protein with low lysine and low
methionine+cystine levels. It could be recommended in the diet 22% protein, 1.10%
lysine and 0.83% methionine+cystine during the starting period (0-5 wk.) followed by
diet contained 18% protein, 0.90% lysine and 0.70% methionine+cystine, during the
finishing period (5-13 wk.) of age.