JWSS - Journal of Water and Soil Science

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‏ This experiment was conducted to determine the performance and intestinal microflora population of broiler chicks in diets supplemented with Roxarsone, Avilamycin and Formycin gold during starter period. A basal diet was formulated according to NRC (1994) recommendation for starter (0-21 d) period and also supplemented with appropriate amounts of the mentioned growth promoters. Each of the treatment was fed to 5 replicates of 18 Ross 308 male broilers. The birds were raised on pen floor for 21 days. The microflora population in crop and ileum parts was measured on appropriate bacteriological media. Results of experiment indicated that supplementation of Roxarsone and Avilamycin, especially their combination to broiler diets, significantly improved body weigh gain of birds (P<0.05). Feed consumption and feed conversion ratios were not affected by any of the mentioned growth promoters. Adding all the growth promoters to the basal diet, except for the treatment of 0.05 percent Formycin gold, decreased total bacterial numbers in crop and ileum parts. Broilers fed diets containing Roxarsone plus Avilamycin had the lowest total bacterial population and were significantly different from those fed the basal diet (P<0.05). Supplementing broiler diets with all the growth promoters increased lactic acid bacteria population in crop, and decreased coliforms population in ileum parts. Lactic acid bacteria population was the highest in broilers fed Roxarsone plus Avilamycin and coliforms population was the lowest in birds fed 0.2 percent Formycin gold, being significantly different from basal diet (P<0.05).

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The present experiment was carried out to determine the effect of feeding a diluted diet together with avilamycin or probiotics on catch-up growth of broiler chickens. Three hundred day-old chicks (Ross 308 hybrid) were assigned to 4 treatments with 5 replicates based on a completely randomized design. The control group, which met NRC requirements, fed a diet consisting of 2900 KCal/kg ME and 20.8%CP. A diluted diet included 2700 KCal/kg ME and 19.4%CP fed to the negative control group during 7 to 21 days of age. There were two additional treatments with 10ppm avilamycin and 100ppm probiotic, respectively. Feeding the diluted diet resulted in reduced body weight gain (P<0.05). Final body weight was higher in chickens having received avilamycin. Although this difference was insignificant compared with the control, it was significant in comparison with other groups. There was no significant difference in terms of feed intake among the treatments. However, birds which received avilamycin had superior feed conversion ratio to other groups. Birds in the control group had the highest abdominal fat content but the difference was not significant. In conclusion, avilamycin significantly increased body weight gain during catch-up growth though the probiotic caused no significant change.

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The real estimation of the volume of sediments carried by rivers in water projects is very important. In fact, achieving the most important ways to calculate sediment discharge has been considered as the objective of the most research projects. Among these methods, the machine learning methods such as decision trees model (that are based on the principles of learning) can be presented. Decision tree method is a hierarchical multi step method which is a recursive data collection technique to binary and smaller sub-divisions until the final analysis cannot be divided. Decision trees consider a priori known set of data and derive a decision tree from it. Then, tree can be used as the set of laws to predict unknown features. In this research, the efficiency of this technique for predicting the suspended sediments in Ilam dam basin has been investigated. To evaluate the accuracy of the methods (written by MATLAB software), statistical criteria such as R, BIAS, RMSE, r2 and MAE were computed. The results showed that based on all the statistical criteria, decision tree in comparison with the sediment rating curve had most consistency with the observed data. Meanwhile, the most important factors for creating tree in the model (that had high correlation with sediment data) are the corresponding discharge and daily rainfall.

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Soil is one of the most important components in forests and distinguishing soil types and soil capability are first steps in forest management. The main aim of this study was to determine relationship between slope aspect and position, and chemical properties of the soil. Soil sampling was done in Tang-e-Dalab in Ilam province which is a part of southern Zagros. Samples were collected in both northern and southern slopes of oak stand (Quercus brantii). In each slope, three transects 50m apart were sampled. Overall number of samples was 60. After data normalization, the means were compared by Duncan test. Slope aspects influenced organic carbon and total nitrogen of soil. These parameters were higher in northern slope than southern one. Slope position showed a significant effect on C, N and P. Also, concentration of C, N and P were increased by moving down the position. Most amounts of C, N and P were 5.84%, 0.58% and 108.19 mg/kg in bottom, middle and bottom of northern aspect, respectively. The least amounts of C, N and P were 3.31%, 0.24% and 37.83 mg/kg in bottom, middle of southern aspect and top of northern aspect, respectively. The results of this study confirmed that nutrient concentration in northern slope was more than southern slope and nutrient concentration in soil was increased by moving downward.

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