Natural resources are valuable capitals for all nations. Rangelands as the most extensive natural ecosystems in Iran provide numerous services, including fodder production and red meat supply, soil conservation and water regulation. Although uncontrolled exploitation of these resources has imposed much pressure and caused many losses within the ecosystems. Impacts of overutilization of nomadic livestock on Semirom rangelands from runoff control perspective has been the core objective of this study. Considering the utilization conditions, vegetation cover was measured within the vegetation types before and after livestock grazing during 2013 grazing season. Curve Number method was selected to evaluate the runoffs originating from rainfalls with different return periods before and after livestock grazing and the difference was considered as the grazing impact. This externality was valuated using replacement cost method. Results showed that utilization pressure is extremely more than grazing capacity which has distorted water regulation function of the rangelands, e.g. it has increased the runoff volume from a rainfall with 2-year return period from 1660884 to 2600487 m3.In other words, it has diminished the potential of rangelands in controlling water runoffs.Economically speaking, the external damage to water regulation function of rangelands was calculated at the rate of 25391 million Rial/year. This information on the externalities of nomadic livestock will provide the useful basis for economic appraisal of the utilization process and adjustment or rectification of economic activities which entail social costs on their way towards private profits.

The increasing incidence of zoonotic diseases needs the urgently of addressed the correlation between human and animal health. Among these zoonotic pathogens, Listeria monocytogenes (L. monocytogenes) causes listeriosis, which has the ability to cause severe health complications, including spontaneous abortions (SA) in pregnant women and encephalitis in immunosuppressed individuals. Its association with livestock, particularly household cattle such as cow, goat, sheep, and buffalo, focuses on the need for an integrated approach to surveillance and prevention. L. monocytogenes in approximately 10% of dairy cattle samples, highlighting the presence of bacteria in the environments and surrounding of livestock’s.[1]

BACKGROUND: Cryptosporidium is an intracellular protozoan parasite that known as the major cause of diarrhea in human and animals. OBJECTIVES: The level of infection to Cryptosporidiumin diarrheic calves of livestock around Tehran and the role of risk factors on its emergence were studied. METHODS: 200 fecal samples from diarrheic calves of livestock’s around Tehran city were collected by cluster sampling method and were studied by modified Ziehl-Neelsen staining method. RESULTS: Existence of Cryptosporidium infection was confirmed in 18 calves (9%). Incidence rate of the infection did not have any significant relationship with sex of animals (p=0.928) and diarrhea history (p=0.640), but the incidence rate of the infection was more in suckling calves with age of less than 2 months with dry fertilizer bedding. CONCLUSIONS: According to the reports of Cryptosporidium infection in multiple studies from different regions of Iran, recognizing the risk factors on the infection incidence can have an important role in controlling the protozoan.

The present research has been done with the purpose of identifying risks and strategies to combating risk in heavy livestock's units Golestan province. This study is a survey kind with a population of 38621 livestock units in Golestan province, have been worked in heavy livestock’s units during 2008-2009. From this population, 380 livestock unit were selected by using stratified sampling method with proportionate scale and studied. We used questionnaire forms and interview with stockmen to obtain information. It’s Face and content validity was approved by Cronbach,s Alpha coefficient. The results of the research showed that most threatening natural risks of according to their priority include heat and cold stress, drought, floods, lightning and accidents and road transport. Between the dependent variable (view of stockmen in relation with role of risk management) with variables economic, technical, educational, health and policy making factors a significant positive correlation was obtained. Also, there is no significant correlation among the variables of age, employment and view of stockmen in relation with role of risk management.

Nanoparticle of Silver, with creating free radicals, can destroy many bacteria, viruses and fungi; therefore they have been recommended as a disinfectant in livestock’s production system. In this study 240 Ross 308 strain chicks in a completely randomized design (CRD) in four treatments at 0(control), 4, 8 and 12 ppm levels of silver nanoparticles in drinking water with four replicates within 16 separate floor pens and 15 birds in each pen were reared. At the end of growing period from each pen two broilers with the average weight were selected and after taking blood sample, sacrificed and their kidney were examined with light microscope by H&E staining. Histopathology showed dose depended changes such as congestion, presence of inflammatory cells including heterophile and lymphocytes, necrosis in tubular cells, proliferative glomerulonephritis and fibrosis. Lesions in the treatments 3 (8ppm) and 4 (12ppm) were more sever than the group 2 (4ppm). Also, increased serum uricacid in treatment 4 (12ppm) compared to control group was significant (p<0.05). It can be concluded that using of nanosilver higher than 8ppm in drinking water can induce sever lesions in kidney of chickens.

This study aims at investigating the effectiveness of nutritional supplements containing vitamins, minerals, and ammonia on the sexual and breeding behaviors in Ghezel sheep. To this end, 28 three and half-year old ewes (50±3 kilograms) with the record of giving birth to two lambs and 4 three-year old (90±3.5 kilograms) rams were used. The ewes were divided into two groups of A (i.e., treatment) and B (i.e., control) with 14 ewes in each group. The treatment group received 40 grams of the compound 7 days before and 7 days after sexual intercourse. The results demonstrate that the treatment group showed sexual receptivity behavior earlier than the control group. Also, such a behavior in the treatment group was accomplished in a shorter period of time than the control group. Moreover, in the treatment group, the breeding rate was demonstrated to be higher than the control group. Nevertheless, the measurement of estrogen, calcium, and phosphate in three different stages showed no significant differences between the two groups. The receptivity power (i.e., the number of successful jumping permission) and the new-born lambs’ weight were not reported to be significant. The current study demonstrated that livestock supplements (nutrients) improve the livestock’s health and sexual behavior. In addition, such supplements have a positive influence on breeding rate.

One of the problems of rangelands is early grazing. Regeneration and Sustainability of some of important range species are threatened by improper entering date. Non structural carbohydrate reserves are considered to be very crucial for regrowth and vigor of range plants after defoliation and for beginning of growing period.Bromus tomentellusis one of the important and wide spread species in Iran. This species is palatable therefore is intensively utilized by all kinds of livestock’s specialy in early growth stage. This study was conducted during growing season of year 2005 in Shahid Hamzavi research station Hanna, Semirom, Isfahan province. Non structural carbohydrate reserves change of this species was investigated in two range sites with heavy grazing and proper grazing histories. Phenological stages selected for sampling were: early growth stage (3-4 leaves), Panicle emergence and seed ripening. Shoot (stem base) and root samples were collected from six random plants in pheonological stages in each site. According to AOAC, Sheffer-Somogy (1940) method, total non structural carbohydrates levels were determined. Results indicated that in seed ripening stage in proper grazing site TNC was 2.23mg/g and significantly (p<0.01) higher than in heavy grazing site (1.25 mg/g). Roots contained significantly (p<0.01) higher levels of TNC than Stems. TNC levels were lowest in early growth stage and highest in panicle emergence stage. This results emphasized the degrading effects of early grazing and panicle emergence to be the proper time for beginning of grazing period.

This study aims at investigating the effectiveness of utilizing barley as a Flushing ration with an energizing source and soybean meal-based diets as a Flushing ration with a protein source the sexual and breeding behaviors in Ghezel sheep. To this end, 36 three and half-year old ewes (51±1.5 kilograms) with the record of giving birth to two lambs and 6 three-year old (89±2.5 kilograms) rams were used. The ewes were divided into two treatment groups of A (i.e., the receivers of barley seeds), B (i.e., the receivers of soybean meal-based diets), and a control group of C with 12 ewes in each group. Also, three rams were utilized randomly in each group. The ewes received the Flushing ration two weeks before and two weeks after sexual intercourse. Hence, group A ewes were fed 400 grams of barley seeds and group B ewes were fed 400 grams of soybean. The results demonstrate that the ewes in the treatment group showed sexual receptivity behavior earlier than the control group ewes; however, the difference was not significant. Also, The receptivity power (i.e., the number of successful jumping permission) and the amount of estrogen, calcium, as well as magnesium levels were not significantly different at pro-estrus and estrus stages. Nevertheless, the amount of phosphorous serum and the new-born lambs’ weight were reported to be significant (p<.05) in the treatment groups. The current study demonstrated that Flushing ration along with both energizing and protein sources improve the livestock’s health and sexual behavior. In addition, such supplements have a positive influence on breeding rate and on the weight of lambs.