Evaluation of urea as a protein source in broiler diets

الملخص EN

This work was conducted in two experiments, the pre-experimental test and the main experiment.

The pre-experimental test was tested the validity of urea for poultry feeding and the mostly safe dietary level was determined.

A total number of 200 one-day old chicks (Arbor Acres), 100 for a pre-experimental test of initial weight 46 g distributed into four equal groups (25 chicks/group) and 100 for the main experiment, weighing on the average 55 g were allocated at random into four groups each of 25 chicks.

The pre-experimental test extended for only 3 weeks (starting period).

The first group was fed on a control starter free from urea, while in the other three groups, the urea form 1.25, 2.5 & 4 % of the diet, respectively.

In the main experiment, urea was tested as soybean meal substituted at 1.25 % as the pre-experimentation dictated.

The first group was fed on a control diet free from urea during the three feeding phases ; starting, growing and finishing.

The second group was fed on the diet containing 1.25 % urea along the three feeding phases, while the third & fourth groups for the last 2nd & 3rd phases or last third phase respectively.

The main experiment extended for 7 weeks duration in three feeding phases ; starting through the first 3 weeks, growing from 3-5 weeks & finishing from 5-7 weeks of age.

In the pre-experimental urea test, the.

1.25 % urea group gained a body weight of 72.5 % that of the control, while the 2.5 & 4 % urea groups gained 53.7 & 37.2 % respectively.

In addition, urea may be toxic at a level of 4 % or more and had advert effect on feed intake and conversion.

In the main experiment, the second group had a reduction in growth rate by 25 % and consuming less amount of food as that of control (84.3 %), and slight high feed conversion (2.52) compared with control (2.21).

In the third group, more feed consumed and less weight gain and by turn more feed conversion.

In the fourth group in which urea feeding was limited to the finishing period, growth rate was nearly similar to control and more feed consumed resulting in a feed conversion index slightly higher than, the control.

There were no differences in the chemical composition of carcass meat and carcass dressing values between different experimental groups.

In contrast, serum urea value of the 2nd & 3rd groups fed urea supplemented diets recorded the highest values compared to 4th and control one, while no differences in the total serum protein were found between the different experimental groups.

It could be concluded that, urea can be added to the diets of broiler chicks at a level of 1.25 % during growmg-finishing & finishing periods without adversely effect on the performanc.