الفهرس 
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Abstract
This experiment was carried out at the poultry farm of Animal production Department, Faculty of Agriculture, Minia University to study the influence of supplementation crude microbial enzymes in improving the feeding value of barley and rice bran in broiler chickens diets. Experimental period was extended to 6 weeks during the period from 16 June to 28 July 2006 on Ross commercial broiler chickens.
At the start of the experiment tow hundred and twenty four, day- old unsexed Ross chicks were obtained from Al-Wady poultry company in Cairo. The chicks were divided into 7 treatments, each of 32 chicks. Each treatment were subdivided into 4 replicates each of 8 (7 treatments X4 replicates X 8 chicks = 224 chicks).
The experimental design was as :
1) T1: Chicks were received diet with yellow corn ,soybean meal, broiler concentrate, to achieve 23% CP and 2926.6 ME (starter diet) and while, finisher diet had 20% CP and 3074.8 ME (control).
2) T2: Chicks were received 75% yellow corn of control yellow corn and 25% barley instead of yellow corn weight by weight.
3) T3: Chicks were received 50% yellow corn of control yellow corn and 50% barley instead of yellow corn weight by weight.
4) T4: Chicks were received 75% yellow corn of control yellow corn and 25% rice bran instead of yellow corn weight by weight.
5) T5: Chicks were received 50% yellow corn of control yellow corn and 50% rice bran instead of yellow corn weight by weight.
6) T6: Chicks were received 75% yellow corn of control yellow corn and 12.5% barley and 12.5% rice bran instead of yellow corn weight by weight.
and 7) T7: Chicks were received 50% yellow corn of control yellow corn and 25% barley and 25% rice bran instead of yellow corn weight by weight.
Moreover, treatments from 2nd to 7th were supplemented with 1 kg Natu- Phos phytase and 1 kg kemizyme dry/ 1 tonne of diet .
The data of the experiment were collected and calculated as follow: Live Body Weight (gm); Live Body Weight Gain (gm);Feed consumption (gm feed/ hen/ day); Feed conversion (gm feed/ gm gain)
Digestion trail was conducted at the end of the experimental period after 6 weeks to estimate the digestion coefficient and nitrogen retention of the experimental diets. Sex chicks from each treatment in sex replicates chicks were divided into two groups, first group in each treatment was fed experimental diet with enzymes, while, the second group fed diet without enzymes. In the second group without enzymes, preliminary period lasted for 3 days followed by other 3 days as a collection period. Feeds and fresh water were offered ad-libitum during the three days of collection period. The feed consumption was recorded, and the manure, which fall on polyethylene sheets, were collected quantitatively every 24 hours.
Feathers and scattered feed were separated or taken out of the manure. The manure of each treatment was pooled together, and then dried at 60oC till constant weight, the dried manure for the successive three days were left for few hours to get equilibrium with it in the atmosphere then, weighed, ground, well mixed and stored in screw- top glass jars for analysis.Birds were weighed before preliminary and collection periods and at the end of the experiment .
The standard plate method was used for determining the number of bacteria (total). The colonies were counted and numbers of bacteria (total) were calculated per one ml.
Total viable bifidobacterial counts were enumerated on modified Lactobacilli MRS (composition is described below), according to the method described by Venting and Mistry (1993).
Counts of the coliform group (Escherichia coil and Aerobacter aerogenes) were determined by the dilution frequency method.
At the end of the experiment, four chicks were randomly chosen from each treatment. The birds were fasted for 12 hours. In the morning of the next day the experimental chicks were weighed individually, then slaughtered until complete bleeding and followed by plucking feather. After the removal of the head, viscera, shanks, gizzard, liver, and heart, the drawn body was weight to determine the dressing weight. The dressing weight percentage was calculated on the basis of live body weight. Also, each of carcass components was proportionally to the live body weight.
Obtained results can be summarized as follow:
1) Live Body weight (gm):
Average of body weight at 6 weeks of age were 1614.30, 1741.10, 1838.90, 1598.83, 1341.68, 1671.43 and 1667.70 gm for treatment 1, 2, 3, 4, 5, 6 and 7 respectively.
2) Body weight Gain (gm):
Average of body weight gain at 6 weeks of age were 1569.92 , 1696.03 , 1795.60 , 1556.95 , 1298.45 , 1626.08, and 1624.08 gm for treatment 1, 2, 3, 4, 5, 6 and 7 respectively.
It could be noticed that, the highest value of body weight and weight gain at 6 weeks of age was found in the treatment (3) which fed diet incorporated with 50% barley; while the lowest value was observed in the treatment (5) which fed diet incorporated with 50% rice bran.
3) Feed consumption:
Accumulative averages of feed consumption at 6 weeks were 3724.70, 3680.60, 3919.48, 3646.83, 3947.48, 3882.20 and 3960.43 gm for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that Ross broiler chicks received diet with 50% barley and 50% rice bran instead of yellow corn represents the highest value of feed consumption in both treatments increased feed consumption by 6.33% from control (3724.70 gm). On another side the lowest value of (3646.83 gm) feed consumption was achieved when chicks fed diet supplemented with 25% rice bran instead of yellow corn, the reduction rate of feed consumption was 2.1% from control treatment.
4) Feed conversion:
The accumulative averages of feed conversion at 6 weeks were 2.37, 2.17, 2.18, 2.34, 3.04, 2.39 and 2.44 for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be observed that the best feed conversion (2.17) was obtained when 25% of barley was substituted instead of yellow corn followed by 50% barley (2.18), the improvement rate was (8.44%), from control (2.37) in treatment (2) may be attributed to increase in body weight gain and decrease in feed consumption, while the improvement rate in treatment (3) was 8.02% is dependent of body weight gain only. However, the worst value (3.04) was recorded by using 50% rice bran.
5) Digestibility Coefficiency:
5.1. The percentages of digestibility coefficients for organic matter in first group fed diets supplemented with Kemzyme Dry and Natu-Phos (Phytase enzyme) were 75.01 % , 77.87 %, 78.12 %, 73.32 %, 68.04 %, 75.50 % and 74.03 %% for treatment 1, 2, 3, 4, 5, 6 and 7, respectively. While, the percentages of digestibility coefficients for organic matter in second group fed diets without enzymes supplementation were 74.01 %, 75.93 %, 73.81 %, 71.71 %, 62.01 %, 70.62 % and 72.99 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the digestibility coefficients for organic matter improved by 1.43 %, 2.55 %, 5.84 %, 8.94 %, 9.72 %, 6.91 % and 1.42 % in treatments 1, 2, 3, 4, 5, 6 and 7, respectively, for broiler fed diets supplemented with Kemzyme dry and Natu-Phos (Phytase enzeyme).
5.2. The percentages of digestibility coefficients for crude protein in first group fed diets supplemented with Kemzyme Dry and Natu- Phos (Phytase) were 78.28 % , 83.87 %, 83.13 %, 78.14 %, 66.39 %, 74.17 % and 68.38 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively. While, the percentages of Protein digestibility in second group fed diets without enzymes were 63.56 %, 66.84 %, 65.49 %, 59.31 %, 60.80 %, 62.00 % and 62.79 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From the present data it could be noticed that, the digestibility coefficients for crude protein was improved by 23.16 %, 25.48 %, 26.94 %, 31.75 %, 9.19 %, 18.11 % and 8.90 % in treatments 1, 2, 3, 4, 5, 6 and 7, respectively, for chicks fed diets supplemented with enzymes compared to non-supplemented diets.
5.3. The percentages of digestibility coefficients for ether extract in first group fed diets supplemented with Kemzyme Dry and Natu- Phos (Phytase enzyme) were 79.39 % , 84.98 %, 77.12 %, 79.65 %, 65.63 %, 74.17 % and 71.25 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively. While, the percentages of digestibility coefficients for ether extract in second group fed diets without enzymes supplementation were 74.86 %, 72.78 %, 70.96 %, 69.67 %, 55.82 %, 69.97 % and 66.27 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the digestibility coefficients for ether extract improved by 6.05 %, 16.76 %, 8.68 %, 14.32 %, 17.57 %, 6.00 % and 7.51 % in treatments 1, 2, 3, 4, 5, 6 and 7, respectively, for broiler fed diets supplemented with Kemzyme Dry and Natu- Phos (Phytase enzyme).
5.4. The percentages of digestibility coefficients for crude fiber in first group fed diets supplemented with Kemzyme Dry and Natu- Phos (Phytase enzyme) were 42.56 % , 44.49 %, 50.01 %, 37.02 %, 21.25 %, 30.77 % and 25.49 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively. While, the percentages of digestibility coefficients for crude fiber in second group fed diets without enzymes supplementation were 33.30 %, 31.18 %, 29.24 %, 23.58 %, 13.94 %, 23.14 % and 17.36 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the digestibility coefficients for crude fiber improved by 27.58 %, 42.69 %, 38.14 %, 57.54 %, 52.43 %, 33.29 % and 46.73 % in treatments 1, 2, 3, 4, 5, 6 and 7, respectively, for broiler fed diets supplemented with Kemzyme Dry and Natu- Phos (Phytase enzyme).
6) Carcas traits:
6.1. Dressing percentages were 70.97 % , 71.97 %, 72.54 %, 71.31 %, 70.65 %, 72.08 % and 71.97 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of dressing percentage (72.54%) was found in treatment 3 which fed diet supplemented with 50% barley; while the lowest value (70.65%) was found in treatment 5 which supplemented with 50% rice bran.
6.2. Liver percentages in all tested diets, revealed that liver percentages were 3.04 % , 2.96 %, 2.64 %, 2.86 %, 3.00 %, 2.46 % and 2.64 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of liver percentage (3.04 %) was found in treatment 1 which fed control diet, while the lowest value (2.46 %) was found in treatment 6 which contained 12.5% barley and 12.5 % rice bran.
6.3. Gizzard percentages were 2.12 % , 2.30 %, 2.39 %, 2.34 %, 3.95 %, 2.63 % and 2.55 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of gizzard percentage (3.95%) was found in treatment 5 which fed diet supplemented with 50% rice bran; while the lowest value (2.12%) was found in treatment 1 which fed (control diet).
6.4. Heart percentages were 0.67 % , 0.59 %, 0.59 %, 0.56 %, 0.61 %, 0.58 % and 0.60 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of heart percentage (0.67 %) was found in treatment 1 which fed control diet. While the lowest value (0.56 %) was found in treatment 4 which supplemented with 25 % rice bran.
6.5. Abdominal fat percentages were 2.50 % , 2.31 %, 1.85 %, 1.42 %, 0.67 %, 1.42% and 1.07% for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of abdominal fat percentage (2.50 %) was found in treatment 1 which fed control diet. While the lowest value (0.67 %) was found in treatment 5 which supplemented with 50 % rice bran.
6.6. Giblets percentages were 5.83%, 5.58%, 5.63 %, 5.76 %, 7.66 %, 5.66 % and 5.78 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of giblets percentage (7.66 %) was found in treatment 5 which fed diet supplemented with 50% rice bran; while the lowest value (5.58%) was found in treatment 2 which fed diet supplemented 25 % barley.
7) Digestive tract organs (%):
7.1. Proventriculus percentages were 0.45 % , 0.39 %, 0.40 %, 0.41 %, 0.50 %, 0.37% and 0.43% for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of proventriculus percentage (0.50 %) was found in treatment 5 which fed diet supplemented with 50% rice bran; while the lowest value (0.37 %) was found in treatment 6 which contained with 12.5 % barley and 12.5 % rice bran.
7.2. Duodenum with pancreas percentages were 1.21 % , 1.12 %, 0.97 %, 1.39 %, 1.44 %, 1.16 % and 1.18 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of duodenum with pancreas percentage (1.44 %) was found in treatment 5 which fed diet supplemented with 50% rice bran; while the lowest value (0.97 %) was found in treatment 3 which fed diet supplemented 50 % barley.
7.3. Jejunum percentages were 2.34 % , 2.75 %, 1.86 %, 1.96 %, 2.51 %, 2.28 % and 2.35 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of jejunum percentage (2.75 %) was found in treatment 2 which fed diet supplemented with 25% barley; while the lowest value (1.86 %) was found in treatment 3 which fed diet supplemented 50 % barley.
7.4. Ceace percentages were 0.19 % , 0.22%, 0.22 %, 0.24 %, 0.29 %, 0.21 % and 0.21 % for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of ceace percentage (0.29 %) was found in treatment 5 which fed diet supplemented with 50% rice bran; while the lowest value (0.19 %) in treatment 1 which fed control diet.
8) Digestive tract length (cm):
8.1. Duodenum lengths were 26.75 , 27.13, 27.63 , 28.50 , 28.50, 26.00 and 28.00 cm for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of duodenum lengths (28.50 cm) was found in treatment 4, 5 which fed diet supplemented with 25% , 50% rice bran; while the lowest value (26.00 cm) was found in treatment 6 which contained with 12.5 % barley and 12.5 % rice bran.
8.2. Jejunum lengths were 141.50 , 156.00, 155.00 , 149.25 , 142.50 , 135.50 and 134.00 cm for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of jejunum lengths (156.00 cm) was found in treatment 2 which fed diet supplemented with 25% barley; while the lowest value (134.00 cm) was found in treatment 7 which fed diet with 25 % barley and 25 % rice bran.
8.3. Large intestine lengths were 8.88 , 9.25, 9.38 , 9.38 , 9.13, 9.38 and 9.00 cm for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of large intestine lengths (9.38 cm) was found in treatments 3 , 4 and 6 which fed diet supplemented with 50% barley, 25% rice bran and 12.5% barley and 12.5% rice bran; while the lowest value (8.88 cm) was found in treatment 1 which fed control diet.
8.5. Ceaca lengths were 17.75 , 19.00, 20.88, 18.25 , 18.88 , 18.25 and 20.13 cm for treatment 1, 2, 3, 4, 5, 6 and 7, respectively.
From these results it could be noticed that, the highest value of ceaca lengths (20.88 cm) was found in treatments 3 which fed diet supplemented with 50% barley; while the lowest value (17.75 cm) was found in treatment 1 which fed (control diet).
9) B¬acterial counts:
The replacing of the yellow corn -based diet with 25 or 50% enzyme treated barley (treatment 2 and 3) or 25% enzyme treated rice bran (treatment 4) substantially increased the count of probiotics (as bifidobacterium) in the small intestine of the Ross broiler chicken as compared with the other treatments. On the other hand, a relatively lower anaerobic bifidobacterium count was observed in cecams of the Ross broiler chicken at the same treatments.
10) Economical Efficiency
The treatment (6) recorded the highest total feed cost of (6.03 L.E) followed by control (5.99 L.E), and then by treatment (4) which represents the least value (5.63 L.E). The experimental groups had recorded the total revenue values with noticeable differences assuming that the price of kilogram live body weight is 7.5 L.E. being 12.08, 13.05, 13.80. 12.00, 10.05, 12.53 and 12.53 L.E./ bird for control (T1), treatment (2) to treatment (7), respectively.
The economical efficiency (E.EF) calculations based on dividing the net revenue value by the total cost the range leis between 1.38 and 0.78 for treatment (3) and treatment (5), respectively. It seems that chicks fed on any barley level had recorded E.EF values higher than control treatment.
The results cleared also that the E.EF. of the treatment (3) was superior compared with the other treatments.
Assuming that the relative E.EF. of the control group equal 100, the other groups recorded relatively the E.EF, being 120.59, 135.29, 110.78, 76.47, 105.88 and 113.73 for treatment 2, 3, 4, 5, 6 and 7 respectively.