Evaluation of some common protein feeds and urea for broilers
Sadek Mohammed Abdulla Almaswary, MSC Theses, Animal and Clinical Nutrtion Dep. Fac. Vet. Med. Assiut University Egypt 2005
Summary 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 and the mostly safe dietary level was determined.
A total number of 350 one day old chicks (Arbor acres), 100 for a pre-experimental urea test of initial weight of 46g distributed into four equal groups (25 chick/ group) and 250 for the main experiment testing the soybean oil meal substitutes and weighing on the average 55g (10 groups, 25 chicks/ group).
The pre-experimental test extended for only 3 weeks, the 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, and 4.0% of the diet respectively.
In the main experiment two vegetable protein sources were tested as soybean oil meal substitutes, the full-fat soy bean and the corn gluten meal-this is in addition to the urea. Each of the plant proteins was used at a maximum rate of 20% and the urea at 1.25% as the pre-experimentation dictated. For each SBM substitute three groups were allotted, the first for feeding the substitute along the three feeding phases; starting, growing, and finishing; while the second and third for the last 2nd and 3rd or last third respectively.
The experiment extended for 7 weeks duration in three feeding phases, starting, through the first three weeks, growing from 3-5 weeks and finishing from 5-7 weeks of age.
The following results were obtained:
I- Pre-experimental urea test
1-The mortality rate was nearly normal as only one chick died from the 25 chicks of the control and the 1.25% urea group and 2 chicks from the 2.5% urea group. From the 4% urea group 5 chicks died mating a rate of 25% in the 3 weeks of feeding pointing to a toxic effect of urea at high concentration.
2-The 1.25% urea-group gained a body weight of 70.6% of that of the control while the 2.5 and 4.0% urea groups gained 50.4 and 32.9% respectively.
3-It seems that urea may be toxic at the level of the 4.0 % or more and have adverse effects on feed intake and conversion resulting in reduced growth rates, but it appears that feeding the level 1.25% is feasible especially if there is soybean oil meal shortage or high pricing.
II-The main experiment:
A-Full-fat soybean test (Trial II):
1-In the first group of FFSB trial there was a slight reduction in growth rate about 8% (body weight at 7 weeks of age 92.3% of that of the control), consuming the same amount of food as that of the control (99.4%), and eventually slightly high food conversion index (2.39 compared to 2.21 in control). In the second group more food consumed and less weight gained and by turn more higher feed conversion index (2.45). In the third group and in which FFSB feeding was limited to the finishing period, growth rate was slightly higher than the control, as also the feed intake resulting in a feed conversion index nearly equal to that of the control (2.24 & 2.21 respectively).
2-There were no significance differences in the chemical composition of carcass meat and carcass dressing values between different experimental groups.
3-Urea concentration was equal in the serum of both control and group 3 and relatively higher than group 1 and 2, while no significant differences in the total protein between different experimental groups.
B-The corn gluten meal test (Trial III):
1-In overall in the 7 weeks of experimentation the feed conversion indices were 5.74, 2.80 and 2.34 for the three CGM groups with only the last two are comparable to the control one (2.21) but with referring to the body weight at 7 weeks of age and the reduced feed intake, only confinement of CGM feeding to the finishing period is the feasible.
2-There were no differences in the chemical composition of carcass meat, carcass dressing values and serum total protein between different experimental groups in trial III.
C-The urea test (Trial IV):
1-In the first group of urea test trial it is a reduction in growth rate about 25% (body weight at 7 weeks of 74.49% of that of the control), consuming less amount of food as that of the control (84.3%), and eventually slightly high food conversion index 2.52 compared 2.21 in control. In the second group more food consumed and less weight gained and by turn more feed conversion (2.40). In the third group and in which urea feeding was limited to the finishing period, growth rate was nearly similar the control, and more feed consumed resulting in a feed conversion index slightly higher than the control (2.33 & 2.21 respectively).
2-There were no differences in the chemical composition of carcass meat and carcass dressing values between different experimental groups.
3-In contrast to serum urea value, group 1 and 2 fed urea supplemented diets recorded the highest values compared to group 3 and control one, while no differences in the total protein between different experimental groups.
A total number of 350 one day old chicks (Arbor acres), 100 for a pre-experimental urea test of initial weight of 46g distributed into four equal groups (25 chick/ group) and 250 for the main experiment testing the soybean oil meal substitutes and weighing on the average 55g (10 groups, 25 chicks/ group).
The pre-experimental test extended for only 3 weeks, the 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, and 4.0% of the diet respectively.
In the main experiment two vegetable protein sources were tested as soybean oil meal substitutes, the full-fat soy bean and the corn gluten meal-this is in addition to the urea. Each of the plant proteins was used at a maximum rate of 20% and the urea at 1.25% as the pre-experimentation dictated. For each SBM substitute three groups were allotted, the first for feeding the substitute along the three feeding phases; starting, growing, and finishing; while the second and third for the last 2nd and 3rd or last third respectively.
The experiment extended for 7 weeks duration in three feeding phases, starting, through the first three weeks, growing from 3-5 weeks and finishing from 5-7 weeks of age.
The following results were obtained:
I- Pre-experimental urea test
1-The mortality rate was nearly normal as only one chick died from the 25 chicks of the control and the 1.25% urea group and 2 chicks from the 2.5% urea group. From the 4% urea group 5 chicks died mating a rate of 25% in the 3 weeks of feeding pointing to a toxic effect of urea at high concentration.
2-The 1.25% urea-group gained a body weight of 70.6% of that of the control while the 2.5 and 4.0% urea groups gained 50.4 and 32.9% respectively.
3-It seems that urea may be toxic at the level of the 4.0 % or more and have adverse effects on feed intake and conversion resulting in reduced growth rates, but it appears that feeding the level 1.25% is feasible especially if there is soybean oil meal shortage or high pricing.
II-The main experiment:
A-Full-fat soybean test (Trial II):
1-In the first group of FFSB trial there was a slight reduction in growth rate about 8% (body weight at 7 weeks of age 92.3% of that of the control), consuming the same amount of food as that of the control (99.4%), and eventually slightly high food conversion index (2.39 compared to 2.21 in control). In the second group more food consumed and less weight gained and by turn more higher feed conversion index (2.45). In the third group and in which FFSB feeding was limited to the finishing period, growth rate was slightly higher than the control, as also the feed intake resulting in a feed conversion index nearly equal to that of the control (2.24 & 2.21 respectively).
2-There were no significance differences in the chemical composition of carcass meat and carcass dressing values between different experimental groups.
3-Urea concentration was equal in the serum of both control and group 3 and relatively higher than group 1 and 2, while no significant differences in the total protein between different experimental groups.
B-The corn gluten meal test (Trial III):
1-In overall in the 7 weeks of experimentation the feed conversion indices were 5.74, 2.80 and 2.34 for the three CGM groups with only the last two are comparable to the control one (2.21) but with referring to the body weight at 7 weeks of age and the reduced feed intake, only confinement of CGM feeding to the finishing period is the feasible.
2-There were no differences in the chemical composition of carcass meat, carcass dressing values and serum total protein between different experimental groups in trial III.
C-The urea test (Trial IV):
1-In the first group of urea test trial it is a reduction in growth rate about 25% (body weight at 7 weeks of 74.49% of that of the control), consuming less amount of food as that of the control (84.3%), and eventually slightly high food conversion index 2.52 compared 2.21 in control. In the second group more food consumed and less weight gained and by turn more feed conversion (2.40). In the third group and in which urea feeding was limited to the finishing period, growth rate was nearly similar the control, and more feed consumed resulting in a feed conversion index slightly higher than the control (2.33 & 2.21 respectively).
2-There were no differences in the chemical composition of carcass meat and carcass dressing values between different experimental groups.
3-In contrast to serum urea value, group 1 and 2 fed urea supplemented diets recorded the highest values compared to group 3 and control one, while no differences in the total protein between different experimental groups.
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