EFFECTS OF FEED RESTRICTION AND PHOSPHORUS ALLOWANCE DURING THE LAYING PERIOD ON THE PERFORMANCES OF BREEDER PEKIN DUCKS

The effects of feed restriction and phosphorus allowance during the la ying period on the performances of breeder Pekin ducks were studied. S ix levels of feed restriction ranging between 80 and 100% (= control a d libitum) and two levels of available phosphorus, 0.27% and 0.54%, we re tested. A dietary level of 0.27% phosphorus was too low to cover th e requirements of laying ducks. It induced a high mortality rate, a de crease in feed efficiency and egg production. Feed restriction during the whole laying period or after peak egg product ion induced a decrea se in body weight, egg production, egg weight and shell strength. The mortality rate was also higher.