سعید مهدی زاده

Evapotranspiration is one of the most important factors in hydrological cycle. Potential evapotranspiration is used to design in irrigation and drainage networks and hydrological studies (Davis & Dukes, 2010). The conducted studies in different regions of the world have shown that the FAO-Penman-Monteith model can be presented as the most accurate method under various climatic conditions (Irmak et al, 2003, ASCE-EWRI, 2005, Jabloun & Sahli, 2008, Martinez & Thepadia, 2010 and Azhar & Perera, 2011). The calibration of the mentioned equation using lysimetric data in a wide range of climatic conditions and its applicability without the requirement for local calibration in different climatic conditions are the benefits of the FAO-Penman-Monteith equation (Landeras et al, 2008). On the other hand, the Valiantzas model is one of the newest methods for estimating ETo. Advantages of using the Valiantzas equations in the estimation of reference evapotranspiration include simple application for spatial calibration, easy application for temporal distribution of reference evapotranspiration values, easy use for routine hydrological applications and simplicity of equations for other hydrological applications (a, b, c, Valiantzas, 2013). The purpose of this study was to evaluate and compare the accuracy of five different Valiantzas models for estimating reference evapotranspiration at the studied stations located in the northwest of Iran (Urmia Lake basin) including Urmia, Salmas, Mahabad, Takab, Tabriz, Sarab and Maragheh and providing the best version of the Valiantzas as the results of which are the highest concurrence with the FAO-Penman-Monteith method.

Solar radiation is an essential factor in irrigation scheduling, hydrological cycle, crop growth simulation models and estimation of reference evapotranspiration. The aim of the present research was to investigate the accuracy of solar radiation estimation models and their effects on reference evapotranspiration. For this purpose, the meteorological data of 4 synoptic stations including Urmia, Takab, Salmas and Mahabad in West of Urmia lake catchment in daily scale were used. Solar radiation was estimated using seven models including, Hargreaves-Samani, Allen, Self-Calibrating, Samani, Annandale, Bristow-Campbell and Angstrom–Prescott. Then, the obtained values were used in FAO- Penman-Monteith equation to estimate the reference evapotranspiration. In order to evaluate the model's accuracy, the statistical indicators including root mean square error, mean bias error and determination coefficient were used. The evaluation results of the models showed that the Angstrom – Prescott model had the best performance, and the Samani method was the weakest method in the studied stations. The average values of the root mean square error for the Angstrom–Prescott and Samani methods in the studied region were obtained 0.48 and 1.43 mm/day, respectively.

Air temperature is one of the most important variables in estimating crop water requirement and climatic studies. In recent years, several intelligent models such as Gene Expression Programming and Bayesian Networks have been used to estimate air temperature. The purpose of the present research is to evaluate the accuracy of these two approaches in prediction of air temperature in a specific day (t) using data of one to seven days before, i.e. t-1 to t-7. For this purpose, a 25-years dataset of daily temperature of two stations in northwest of Iran, namely Urmia and Tabriz were collected and used for models performance comparison. The results showed that Gen Expression Programming and Bayesian Networks methods were capable to predict the minimum, mean and maximum air temperature with acceptable accuracy. However, the Bayesian networks method showed relatively better performance comparing to the Gene Expression Programming. The findings revealed that in testing stage of Bayesian networks method for Urmia station, the values of determination coefficient (R2) and root mean square error (RMSE) in the best scenario are 0.92 and 2.5 ◦C for minimum temperature, 0.96 and 1.83 ◦C for mean temperature, 0.96 ◦C and 2.3 ◦C for maximum temperature respectively. The corresponding values of statistical indices for Tabriz station in Bayesian networks method were found to be 0.93 and 2.42 ◦C for minimum temperature, 0.97 and 1.90 ◦C for mean temperature and 0.95 and 2.42 ◦C for maximum temperature. In general the mean temperature was predicted more accurately by both approaches in study stations.

This study was carried out to evaluate the effect of different levels of metabolizable energy (2750, 2900 and 3050 kcal/kg) and crude protein (13, 15 and 17%) in the diet on the performance and egg quality of native laying hens of Mazandaran province at the first stage of production. For this purpose, two hundreds seventy 24-week-old native hens were randomly assigned to a 3×3 factorial design experiment. Egg production and feed intake were affected by different levels of energy (P0.05). Moreover, different levels of crude protein had significant effect on egg production (P

Correct estimation of reference evapotranspiration (ETo) needs to estimate accurate solar radiation values. There are many models to estimate solar radiation so that one of these relationships is Angstrom-Prescott (A-P) equation. The accuracy of Angstrom-Prescott equation in estimating solar radiation value depends on the estimation accuracy of a and b coefficients of the mentioned equation. The purpose of the present research was to investigate the accuracy of models for estimating coefficients in A-P equation and their effects in the solar radiation and reference evapotranspiration values. To do this purpose, the meteorological data of four synoptic stations including Urmia, Takab, Mahabad and Salmas in the Urmia lake watershed in the daily scale from 1998 to 2008 were used. The models which used for the determination of Angstrom-Prescott equation coefficients were included models based on the annual average of relative sunshine hours , elevation and , elevation and latitude and , elevation and latitude, annual average of air temperature, elevation. The obtained coefficients were used to compute the solar radiation values in Angstrom-Prescott equation and then reference evapotranspiration was calculated by FAO-Penman-Monteith equation. To evaluate the models accuracy, statistical indices including RMSE, MBE, MPE and R2 were used. The evaluation results of the models showed that the model based on annual average of relative sunshine hours (Rietveld model) had the best performance in determining the coefficients of AngstromPrescott equation. The average values of RMSE, MBE, MPE and R2 indices for actual reference evapotranspiration and reference evapotranspiration obtained from coefficients of mentioned model were found 0.33 and 0.25 mm/day, 6.27% and 0.9977, respectively. For AngstromPrescott equation coefficients from selected model, a=0.26 and b=0.43 were suggested in the studied stations in the Urmia lake watershed.

This study was conducted with the aim of determination of chemical composition, degradability fractions and nutritional value of Astragalus crenatus Schult. Two sites with different elevation ranges (1500-1700 and 1900-2100 meters from sea level) were selected to collect the data in highlands ranges of Hir to Neor, Ardebil County. The data sampling was carried out in three phenological stages (vegetative growth, flowering and seeding stages). Plant samples were analyzed and their NDF and ADF were measured using Van Soest method. AOAC common lab methods were used to measure plant samples chemical composition. Ruminal degradability of samples was determined by in situ technique (e.g. two ruminal cannulated Moghani rams). The results showed that digestibility and degradability of dry matter, organic matter, NDF and ADF of samples from the site located in 1900-2100 meters from sea level ranges were significantly higher than the site in lower site (p<0.01). Moreover, the analysis of the collected samples showed that the NDF and ADF values in form of percentage of dry matter for species in higher elevations range sites were higher. The dry matter contents of plant samples differed significantly in various phenological stages (p<0.01). Results showed that the plant samples in vegetative stage had the highest ash and ruminal and post-ruminal digestibility in both sites. The plants in vegetative stage had lowest NDF, ADF and organic matter content compared to the other phenological stages. In conclusion, the degradability of dry matter of the species in vegetative growth stages was more than other stages, indicating that the nutritional value of plant species is reduced in flowering and seeding stages. It can be concluded that late spring is the best time for grazing this species and it can be considered in grazing management plans of the study area.

In a dairy farm with 1600 milking cows، a 3. 5- month old Holstein female calf showed a prominent hard subcutaneous mass at the lower part of the neck resulted in rumen bloat and dyspnea. In postmortem examination of the calf، apart from huge mass of thymus، astonishing enlargement of innumerable lymph nodes and a large spleen were noticed as well. In histopathologic study، replacement of the thymus، lymph nodes and spleen tissues with immature malignant lymphocytes were found. The adjacent muscles and fats of the extra-thoracic thymus lymphoma were invaded by the neoplastic lymphoid cells. CBC of the patient showed leukocytosis (more than 45000) and lymphocytosis (higher than 93% with 2% atypical lymphocyte). PCR of blood sample of the calf was positive and in ELISA test، the serum antibody was negative (28pp). PCR and ELISA of the mother of this calf were negative while PCR of a sample from the dairy milk tank was strongly positive. It is suggested that due to lack of maternal passive immunity and immaturity of immune system، following ingestion of BLV- contaminated milk، the calf became infected، resulted in occurrence of atypical and widespread viral lymphoma.. By the best knowledge of the authors this is the first report of this kind of calf lymphomsarcoma world-wide.

Corynebacterium Pseudotuberculosis (CP) is the causative agent of soil born disease (SBD). This agent has two types of toxin called CWLT and PLD which gives CP to be able to inter in phagocyte and distributes with it in the host body and damages the membrane of lymph or blood capillaries, erythrocyte and specially subcutaneous tissues and lymph nodes. CP polluted soil is distributed by wind and stabilizes on trauma and or insect damaged skin and then localizes in related subcutaneous tissues and cause necrosis and abscess formation in lymph and/or blood originated texture. In cattle CP can occasionally localize in gastrointestinal damaged mucosa and lung damaged structure and induces necrosis and abscess formation in related GI submucosal and lung tissues. From 8 June to 22 Sept. 2013 SBD affected 8.8% of 2000 dairy cattle. 67% of the affected animals were culled and the others were treated by penicillin and oxytetracycline, those apparently got rid of the disease. In this outbreak the percentage of affection in first to fifth pregnancy were 42.3, 20, 7.3, 12 and 5 respectively. SBD affected even a 6 Mold heifer. In this herd carpal joints were affected much more than tarsal ones and as a cellulitis did distend to regional lymph node. Clinically engaged joints were ulcerative, inflamed and painful and engaged lymph nodes which became an enlarged abscess. Histopathologic findings were invasion of lymph and/or blood capillaries and their complications, formation of caseinated masses which later on became obsess. In this outbreak CP was identified and the CAMP test of the isolated bacteria was positive. Considering the fallowing information: SBD is a zoonosis, difficulty to treat, SBD being endemic for more than 5M; therefore authors of this article deeply believe that till achieving a capable vaccine against cow’s SBD, all affected cattle should be. ..

Accurate estimation of crop water requirement is the basic step for designing and scheduling of irrigation and drainage projects. Evapotranspiration (ET) is a stochastic variable, therefore to reduce the risk level, it is needed to select and use proper evapotranspiration probability levels. In this research, 24 years meteorology data of Orumieh synoptic station have been used to estimate ET0. Also for investigation the effect of ET0 calculation methods on its value, FAO Penman-Monteith (FP-M) and Hargreaves-Samani (H-S) models were selected. Daily ET0 distribution curves with different probability levels for each method were extracted. Differences between maximum daily ET0 values (calculated by FP-M method) with 75% and 50% probability level was 1.0 mm/day (equivalent to 13%) and between 90% and 50% was 1.9 mm/day (24%). Similarly for H-S method the difference was 0.5 and 0.9 mm/day (8% and 15%), respectively. Also at a particular probability level, there was noticeable difference between values of FP-M and H-S methods. In order to understand the impacts of calculation period length on mean daily ET0 value, daily ET0 with 99% probability, and moving average of daily ET0 were calculated for 1, 3, 5, 7, 10, 15, 20, 25 and 30 day perrids. After determination of occurrence date of average maximum daily ET0 for the above periods, average of maximum daily ET0 with different probability levels for the periods of 1 to 30 days were determined. The occurrence of peak dates within 1 to 20 day periods, for FP-M method was 2 weeks after H-S method but for 25 and 30 day periods the dates were the same. The results showed that the peak mean daily ET0 of FP-M method for 5 day periods at 50% and 75% probability levels were 7.8 and 8.7 mm/day (12% difference) and for H-S method they were 6.1 and 6.6 mm/day (8% difference).