Methionine and lysine supplementations in diets or drinking water of one-phase low diet protein feeding system : effect on body weight, feed utilization and age at sexual maturity in growing chicks

Abstract EN

This experiment was conducted to study the effect of methionine and lysine supplementation out to the level of 120% of requirements in feed or drinking water for one-phase low protein diet during growing period.

A total number of 200 one-day old H and N brown nick female chicks were divided into three groups.

Control group (C) fed according to the strain requirements on diets with 17, 15 and 14% CP during the periods of 0-5, 6-15 and 16-18 weeks of age.

The other two groups were fed on one-phase low protein diet (14% CP) supplemented with methionine and lysine to the level of 120% of requirements either in feed (F) or drinking water (W).

Live weight has significantly (P < 0.05) decreased at the first five weeks of age in groups F and W compared to group C.

However, during the growing period (0-18 weeks), live body weight of group W (1522 gm) did not significantly differ than group C (1533 gm).

Growth rate showed no significant differences in the experimental groups throughout the whole growing period.

Feed intake values (gm / bird / day) during 0-18 weeks of age were 55.05, 53.09 and 56.21 in C, F and W group, respectively.

Through 0-18 weeks old, feed efficiency values were 0.213, 0.210 and 0.206 for the same groups, respectively.

Birds in F and W groups consumed less protein than group C (9.38 gm / bird / day) during 0-18 weeks of age.

Moreover, F and W groups recorded insignificantly better protein utilization value compared to C group.

Age at sexual maturity was 130, 125 and 129 days for birds grown on C, F and W groups, respectively.

It could be recommended to use one-phase low protein diet (14% CP) supplemented with methionine and lysine to the level of 120% of requirements either in diet or drinking water for H and N female chicks during growing period.