Aetiology of livestock fetal mortality in Mazandaran province, Iran

In the farming industry, the productivity of livestock herds depends on the fertility efficiency of animals. The accurate diagnosis of a broad range of aetiological agents causing fetal death is often difficult. Our aim was to assess the prevalence rates of Toxoplasma gondii, Neospora caninum, and Brucella spp. infections in ruminant abortion using bacteriological culture and molecular techniques in Mazandaran Province, northern Iran. Samples were collected from 70 aborted sheep, goat, and cattle fetuses between September 2014 and December 2015. Necropsy was performed on all the received samples, and brain tissue and abomasal content were obtained from the aborted fetuses. Protozoan infections were detected by specific polymerase chain reaction (PCR) and bacterial agents using bacteriological examinations and PCR assay. Infectious pathogens were detected in 22 out of 70 (31.4%) examined fetuses. Moreover, T. gondii, N. caninum, and B. melitensis were verified in 13 (18.6%), four (5.7%), and two (2.85%) samples, respectively. Our results showed that infection with the mentioned pathogenic agents may lead to fetal mortality, which can be a major cause of economic loss. The listed pathogens could be considered important etiological agents of fetal loss in Mazandaran Province, for which appropriate control measures such as vaccination and biosecurity can be implemented to prevent infection and reduce reproductive loss in livestock farms

Carnivores as Important Reservoirs of Intestinal Helminthic Infections in Mazandaran Province, Northern Iran

Background: Intestinal parasites are the most common causes of gastrointestinal disease in canine. Stray dogs and wild candies can represent potential reservoirs of enteropathogens to other hosts. Therefore, present study determined the prevalence of intestinal parasites in canine in Mazandaran Province, northern, Iran. Methods: Overall, 58 small intestinal samples of animals (42 stray dogs and 16 jackals) were collected from Oct 2012 to Dec 2013. The intestine contents were studied to detect and identify helminth infections. Then, the helminths were collected and their morphological traits were identified. Results: Overall among infected stray dogs and jackals, 11 species were found. Three species of nematodes, seven species of cestodes and one trematode were observed. The prevalence of gastrointestinal helminths of stray dogs and jackals were 59.5% and 50%, respectively. Among registered zoonotic helminths A. caninum was the predominant parasite both stray dogs and jackals. Interestingly, Spirometra spp. was reported in these animals. Moreover, A. caninum showed a higher percentage rate in center region of province. Conclusion: There are the clear risks of zoonotic helminths parasites infection in this region. Therefore, understanding the epidemiology of zoonotic parasite infection is useful for health care access both domestic animals and humans health

Numerical simulation of sand transfer in wind storm using the Eulerian-Lagrangian two-phase flow model

In this paper a two-dimensional gas-solid flow model is used to investigate the sand particles carrying velocity of the Iran eastern desert area around the railway track as a case study. Reynolds-averaged Navier-Stokes (RANS) equations and Discrete Phase Method (DPM) are used to simulate the characteristic movement of sand particles in wind flow. A random sample is gathered from the sand near the railway in Iran deserts. The sample is classified based on weight and diameter according to AASHTOO T27 and sand distribution is determined. Using simulations, the carrying velocity of sand in each category in wind storm is determined. Finally, the sand distribution of the sample is imported to the model by the Rosin-Rummler dissipation model. The behavior of sand particles in storm considering wind blowing scheme of desert is studied parametrically. The results can be used for estimating the sand mitigation of a special desert and land desertification control around railway tracks

Comparing performances of a triangular embankment and a rigid wall-type barrier in sandstorms using simulation and a wind tunnel test

The movement of sand particles and their accumulation on railway tracks are among the major problems observed in desert areas, which may impose huge maintenance and repair costs. One solution is to create a protective barrier in the vicinity of railway tracks to reduce sand deposition on these tracks. The present study introduced a triangular embankment due to its construction simplicity and low cost and compared it with a rigid wall-type barrier. At first, both models were compared in terms of the streamline and the sand mass flux with a two-phase flow of sandstorm numerical calculations. Then, the sand mass flux was measured for the rigid wall-type barrier using an experimental wind tunnel test. Moreover, the effects of wind speed, wall height, the zero-porosity barrier on the mass flux profile, and the deposition reduction of sand particles were examined after the barrier placement. Finally, the triangular embankment behavior was studied in a wind tunnel. The results revealed that the triangular embankment could increase the safe area after the barrier placement by up to 25%. Further, the triangular embankment was proven to be a permanent and cost-effective solution for protecting railway tracks in windblown sand-prone areas

Pyrethroid resistance in Iranian field populations of Rhipicephalus (Boophilus) annulatus.

Resistance to acaricides in ticks is becoming increasingly widespread throughout the world; therefore, tick control requires resistance monitoring for each tick species. The aims of this study were to monitor the susceptibility status of the cattle tick, Rhipicephalus (Boophilus) annulatus (Acari: Ixodidae), against pyrethroid acaricides from Mazandaran Province, northern Iran, and where resistance was evident, and establish the possible underlying mechanisms. Fully engorged adult R. (B.) annulatus females collected on cattle from Mazandaran Province. Twenty-nine tick populations produced 10–18 days old larvae and bioassayed with cypermethrin and λ-cyhalothrin by larval packet test and the levels of detoxification enzymes were measured. Population AM-29 had a maximum resistance ratio (RR99) of 20.21 to cypermethrin and 53.57% of the tick populations were resistant at LC99 level. With λ-cyhalothrin, 17.86% of the tick populations were resistant and AM-29 was the most resistant population with RR99 = 4.54. AM-29 also showed significant elevation of cytochrome P450 monooxygenase (P450) and glutathione S-transferase (GST) (2.76- and 2.39-fold, respectively) (P < 0.001). Rhipicephalus (Boophilus) annulatus showed resistance to pyrethroid insecticides with elevated levels of P450, GST and para-nitrophenyl acetate (p-NPA) in resistant populations. Operational failure was noted in controlling R. (B.) annulatus by pyrethroid insecticides, therefore alternative pest management measures should be adopted in Iran. For the first time, a new estimate of insecticide resistance based on effective dose recommended by the pesticide manufacturer termed Operational Dose Ratio (ODR) is defined and discussed