الفهرس 
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Abstract
This study was carried out at the poultry farm, Department of Animal production, Faculty of Agriculture, Minia University, from May 8 to 19 June 2004.
It was designed to study the effect of partial and or complete substitution of soybean meal protein in broiler diets with mung bean and or treated full-fat soybean on the growth performance and carcass traits of broiler chicks.
Two hundred fifty six, one-day old, Hubbard broiler chicks were used in this study.
The seeds from both mung beans and full- fat soybeans were soaked in tap cold water with a ratio of 25% (w/w) for 12 hour with continuous string of seeds in water. Then seeds were spread in 2 Cm layer on galvanized trays and heated in an oven at 105ºC for 15 minutes.
After heating treatment the seeds were spread in thin layers in room temperature for 48 hours, then it crushed to use in diets formulation.
Eight diets from each of the starter and grower diets were formulated to be isocaloric and isonitrogenous. All diets were formulated from different sources of plant protein 100%, except of 1st diet which contained fish meal and served as a commercial control treatment (treatment 1).
- Diet 2 was composed in which, soybean meal was the main source of protein and served as a reference for other plant protein sources (treatment 2).
- Soybean meal protein in the dietary treatments from 3-8 was replaced by mung bean protein and or full-fat soybean protein as follow:
- Diets 3 and 4 were composed in which soybean meal protein was replaced completely by proteins derived from full-fat soybean or mung bean (T3 and T4) respectively. Whereas in diets 5 and 6 only half of soybean meal protein in the diets was replaced by proteins derived from the previous mentioned sources (T5 and T6).
- In diet 7 soybean meal protein was completely replaced by full-fat soybean and mung bean proteins at 1: 1 ratio (T7).
While, diet 8 was composed from the three sources of plant proteins (soybean meal, full-fat soybean and mung beans) at 1: 1: 1 ratio (T8).
The experimental diets satisfied the N.R.C. requirements for broiler chicks (N.R.C. 1994)
The results revealed the following:
(A) Nutrients digestibility:
1- The starter diets composed of soybean meal as the main source of protein (T2) or in combination with mung bean (T6) had total digestible nutrients comparable to the control diet (T1) contained animal protein (73.6% or71.6% vs 71.3% respectively)
2- The grower diets composed of soybean meal protein alone (T2) as a main source of plant protein or mung bean (T4), mung bean plus soybean meal proteins at 1:1 ratio (T6) or mung bean plus full- fat soybean proteins at 1: 1 ratio (T7) had total digestible nutrients exceeded or equal to that of the control (T1) diet (70.1%, 72.5%, 72.0%, 70.8%, vs 69.1% respectively)
3-starter and grower diets composed of full- fat soybean (T3) had lower (p<0.05) crud protein digestibility and total digestible nutrients compared to other dietary plant protein source.
(B) Body weight and body weigh gain:
1- Broiler chicks fed on plant protein diets from different sources and ratios had negative (p<0.05) effect on body weight and body weight gain compared to those fed on the control diet (T1) at 3 and 6 weeks of age.
2- The negative effects on body weight resulted from using different sources of plant protein instead of animal protein( control treatment) in broiler chick diets represented about 6.44%, 35.75%, 31.15%, 31.26%, 2.13%, 25.11% and 34.20% for treatments 2,3,4,5,6,7 and 8 respectively at marketing age (at 6 weeks of age).
3- The retardation in body weight gain resulted from using different sources of plant protein compared to the control diet represented about 6.65%, 36.67%, 32.31%, 32.02%, 2.24%, 25.78% and 35.08% for diets 2, 3, 4, 5, 6, 7 and 8 respectively during the whole experimental period (from 0-6 week old).
4- The depression in body weight gain resulted from using plant protein derived from full-fat soybean (T3) , mung bean (T4), soybean meal + full-fat soybean (T5), mung bean + full-fat soybean (T7) or soybean meal + full-fat soybean + mung bean (T8) were 32.16%, 27.49%, 27.18%, 20.49% and 30.45% respectively compared to broiler chicks fed on the diet composed of soybean meal protein (T2) as a main source of protein at 6 weeks of age.
5- Through the combination between soybean meal protein and mung bean protein at 1:1 ratio during manufacture of broiler chick diets could be overcome the negative effects resulted from using plant protein sources on body weigh and body weigh gain at 6 weeks of age (marketing age).
(C) Feed consumption:
1- Replacing animal protein in either starter or grower diets by soybean meal protein (T2) or replacing half of soybean meal protein in the reference diet (T2) by mung bean protein (T6) had no adverse effect on feed consumption of broiler chicks compared to the control diet (T1).
2- Substitution of soybean meal protein in the reference diets (T2) by full-fat soybean protein (T3) had an adverse effect on feed consumption of broiler chicks by about 20.49% and this adverse effect could not be overcome by mixing with other dietary plant protein sources.
3- Replacing mung bean protein (T4) instead of soybean meal protein had an intermediate adverse effect on feed consumption which represented about 12.05% and its adverse effect could be overcome by mixing with soybean meal protein at 1:1 ratio (T6).
(D) Feed conversion ratio:
1- Offering the diet contained soybean meal as a main source of protein alone (T2) or in combination with mung bean protein at 1:1 ratio (T6) to broiler chicks insignificantly deteriorated feed conversion ratio by about 6.9%, or 4.74% compared to the control diet (contained animal protein).
2- Substitution of soybean meal protein in the reference diet (T2) completely by protein derived from full-fat soybean (T3), mung bean (T4) ,or full-fat soybean protein + mung bean protein at 1:1 ratios (T7) or partially by full-fat soybean (T5) or two third of both (T8) deteriorated (p<0.05) feed conversion ratios by about 25.00% , 29.74%, 11.64%, 22.41%, , and 27.59% respectively compared to the control treatment (contained animal protein) at 6 weeks of age.
3- Substitution of soybean meal protein in the reference diet (T2) completely (at 100% level ) by plant proteins derived from either full-fat soybean (T3) or mung bean (T4) or partially at 50% or 66.6% levels from full-fat soybean (T5) or full-fat soybean + mung bean (T8) deteriorated (p<0.05) feed conversion ratios of broiler chicks by about 16.94%, 21.37%, 14.52% and 19.35% respectively compared to the reference diets (T2) at marketing age (at 6 weeks of age) .
(E) Protein intake and efficiency of protein utilization:
1- broiler chicks fed on the diet of soybean meal (T2) consumed protein similar to those fed on the animal protein diet (control diet T1) while, mung bean decreased (p<0.05) protein intake compared to control (T1) or soybean meal (T2) diets, but this negative effect could be alleviated by mixing it with soybean meal proteins at 1:1 (T6) ratio in broiler chicks.
2- Broiler chicks fed on the diet of full-fat soybean (T3) recorded the lowest (p<0.05) total protein intake and it is negative effect on protein intake could not be overcome by mixing it with other plant protein sources.
3- Broiler chicks fed on the diets contained soybean meal as a main source of protein alone (T2) or in combination with mung bean protein at 1:1 ratio (T6) had comparable protein efficiency ratio to those fed on the control diet (T1) (contained animal protein).
4- The efficiency of protein utilization by broiler chicks fed on diets of full-fat soybean (T3), mung bean (T4) ,soybean meal + full-fat soybean (T5) or soybean meal + full-fat soybean + mung bean (T8) was inferior (p<0.05) than other dietary treatments.
(F) Energy intake and efficiency of Energy utilization:
1- Using the diets of soybean meal protein alone (T2) or in combination with mung bean protein at 1:1 ratio (T6) had no adverse effect on energy intake of broiler chicks compared to the control diet (T1).
2- Substitution of soybean meal protein in the reference diet (T2) completely by protein derived from full-fat soybean (T3), mung bean (T4), or full-fat soybean protein + mung bean protein at 1:1 ratios (T7) or partially (at 50% level) by full-fat soybean (T5) or two third of both (T8) decreased (p<0.05) energy intake compared to the control diet (T1).
3- Replacing full-fat soybean protein (T3) instead of soybean meal protein in the reference diet (T2) had an adverse effect on energy intake of broiler chicks and this adverse effect could not be overcome by mixing with other dietary plant protein sources.
4- Broiler chicks fed on the diets composed of soybean meal (T2) or soybean meal + mung bean at 1: 1 ratio (T6) as the main source of proteins had similar efficiency of energy utilization compared to those fed on the control diet (T1).
5- The efficiency of energy utilization by broiler chicks fed on diets of full-fat soybean (T3), mung bean (T4) ,soybean meal + full-fat soybean (T5) or soybean meal + full-fat soybean + mung bean (T8) was inferior (p<0.05) than other dietary treatments.
(G) Mortality rate:
Dietary treatments had insignificant effect on mortality rate.
(H) Economic return:
1- Broiler chicks fed on the diet of SBM+ MB (T6) recorded the best (p< 0.05) economic return followed by those fed on the control (T1) or the diet of FFSB+ MB (T7) at 6 weeks of age.
2- The superiority in economic return for broiler chicks fed on the diet of SBM+ MB (T6) represented about 27.3% or 70.7% over those fed on the control (T1) or SBM (T2) diets respectively, at 6 weeks of age.
3- The poorest (p <0.05) economic return was recorded by broiler chicks fed on the diets of FFSB (T3), SBM+ FFSB (T5) or SBM+ FFSB+ MB (T8).
(I) Carcass traits:
1- Broiler chicks fed on the diet contained soybean meal as the main source of protein (T2) achieved comparable carcass traits to those fed on the control diet (T1).
2- Substitution of soybean meal protein in the reference diet (T2) completely or partially by full-fat soybean or mung bean protein in broiler chick diets had negative effect (p<0.05) on dressing percentage.
3- Replacing soybean meal protein completely by mung bean protein (T4) increased (p<0.05) giblets and abdominal fat percentages compared to the reference diet (contained soybean meal as the main source of protein) (T2) or the control diet (contained animal protein) (T1).
4- The substitution of half soybean meal protein by full-fat soybean (T5) decreased (p<0.05) abdominal fat weight and percentage.
5- There was a slight tendency for increasing liver weight percentage by feeding diets contained different plant protein sources.
(J) Meat quality:
1- Dietary treatment composed of soybean meal as the main source of protein (T2) improved (p< 0.05) meat quality of thigh muscles based on cooking loss percentage compared to the control diet.
2- Cooking loss in breast and juice holding capacity in both breast and thigh muscles were not adversely affected by different dietary plant protein sources.
(K) Some digestive tract measurements:
1- Broiler chicks fed on the diets contained full-fat soybean or mung bean proteins showed pancreatic hypertrophy.
2- Substitution of soybean meal protein (T2) completely by either mung bean (T4) or full-fat soybean proteins (T3) or partially (at 50% level) by full-fat soybean protein (T5) increased (p< 0.05) the relative weight of spleen compared to the control treatment.
3- Broiler chicks fed on the diet of soybean meal protein + full-fat soybean (T5) recorded the higher (p< 0.05) relative weight of duodenum compared to the control (T1) and soybean meal (T2) diets.
4- Broiler chicks fed on the diet contained soybean meal as a main source of plant protein (T2) recorded higher (p< 0.05) rectum thickness, but the opposite trend was observed when half of soybean meal protein in the reference diet was replaced by full-fat soybean (T5) compared to the control diet (T1).
5- Broiler chicks fed on the diet of mung bean (T4) or soybean meal + full-fat soybean (T5) had lower (p<0.05) ceacum thickness compared to the control treatment.
6- Dietary treatments had insignificant effect on the absolute weight, length and thickness of duodenum and on the absolute and relative weight, length and thickness of small intestine, the absolute and relative weight and length of rectum or on the absolute weight and length of ceacum.
Conclusion
Generally, it could be concluded that, formulation of broiler chick diets from both soybean meal plus mung bean proteins at 1: 1 ratio as the main sources of plant proteins increased the profitability of the producers much better than using the commercial diets or the diet composed of soybean meal alone as a main source of protein, but this depends on the quantity produced of mung bean and when it’s price permits.