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چکیده
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The effect of a CTCzyme enzyme on broiler performance and dry matter output in corn-soybean meal diets was investigated.120 One-day-old male chicks received the same basal diet based on corn-soybean meal for 19 d. At that day birds were randomly allocated to 4 treatments, each of which had 6 replicates of 5 birds. The birds were weighted by pen. Aliquots of the basal diet were supplemented with 4 levels of the CTCzyme: 0%, 0.025%, 0.05% (recommended level) and 0.1%. Chromic oxide was used as tracer. After 8 d of acclimation excreta was collected daily, weighted and dried at 130°C for 24 h to obtain the dried matter output. After 7 d of excreta collection the birds were weighted and the experiment was terminated. There were no significant differences for body weight gain, feed conversion or feed intake. The addition of CTCZyme at the inclusion level of 0.05%, and 0.1% significantly reduced (P < 0.002) the daily dry matter excreta output per bird. Analysis of the excreta showed a reduction of the nitrogen level as the level of CTCZyme increased indicating an increment of nitrogen utilization by the bird. Gross energy of the excreta decreased as the inclusion level of the enzyme increased. Calcium and phosphorus levels increased with increasing levels of the enzyme, possibly due to a concentration effect. Higher levels of chromium in the excreta were observed with the increment of the enzyme suggesting an improvement on the feed digestibility product of the effect of the β-mannanase. These data indicate that nutrient digestibility is enhanced by the effect of CTCZyme. The reason for the increasing digestibility not showing on broiler performance may be due to the short time the enzyme was included in the diet. Also, it has to be taken into account that the diet protein levels covered by large the birds growing needs and it is possible that birds were just not able to assimilate the now more available amino acids due to the effect of CTZyme.
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