BACKGROUND: Cryptosporidium parvum is a protozoan parasite which belongs to apicomplexa phylum. The parasite infects both wild and domesticated animals and human beings as well. OBJECTIVES: The purpose of the present study was to detect oocyst shedding and diarrhea pattern in experimental cryptosporidiosis and their correlation with weight loss in neonatal calves. METHODS: Twelve Holstein calves of both sexes were obtained at birth from dairy farm and randomly divided into two groups of 6 calves. Six calves were orally infected with 107 C.Parvum oocysts at the 12h post parturition. The control group was not infected. Clinical signs were examined and fecal samples were collected by the rectal examination twice a day. All calves were weighed from day 0 to day 30 with 3 days intervals to determine effects of cryptosporidiosis on weight gain. RESULTS: All infected calves were noticeably depressed and had a decreased appetite from 3 days post inoculation (DPI) while they received colostrum. Subsequently, watery diarrhea with clumps of mucus and yellow or pale changes of feces color were observed. The infected calves have had diarrhea for 5-8 days that remarkably had got dehydrated. The most severity of diarrhea was 4-6 DPI. Oocyst excretion started 4 DPI, peaked at 6 DPI (60.48×106±9.03oocysts/g feces) and continued until 11 DPI. Control calves had no diarrhea and other clinical signs during the whole period of the trial. The mean weight gain of control group was significantly higher than inoculated group during experiment (p<0.001). The Weight of the infected calves was retarded until 9 days old and then risen subsequently. CONCLUSIONS: Present study showed the role of C.Parvum as the primary cause of diarrhea and weight loss among neonatal calves.

BACKGROUND: Theileriosis is a blood protozoan disease with high mortality in cattle in tropical and subtropical regions of the world. Several studies were conducted to identify Theileria species in infected cattles and vector ticks by microscopic examination. However, microscopic technique has lower sensitivity compared to molecular method.                  OBJECTIVES: This study was carried out to identify Theileria species and its carriers in cattles of Yazd city, sing semi nested PCR. METHODS: Between June to September of 2012, 100 EDTA blood samples and 249 ticks were collected from Holstein breed with no history of vaccination against the ileriosis in Yazd area. The collected samples were transported to the laboratory, then prepared the blood smears and stained with Giemsa method. Also, the collected ticks were separated into 50 tick pools, according to their species. Then their salivary glands were removed using stereomicroscope in 0.85% saline. DNA of blood and salivary glands was extracted using a commercial kit and analyzed by Semi-nested PCR. PCR-RFLP was also used to differentiate Theileria lestoquardi from Theileria annulata in positive samples of ticks. RESULTS: Ring forms of Theileria spp. were found in 4 (4%) of blood smears. All ticks were Hyalomma a.anatolicum. Results of PCR were indicated that 11 (11%) of blood samples and three pools of tick’s salivary glands were infected with Theileria. Theileria annulata were only detected in all positive samples by Semi-nested PCR. The results of PCR-RFLP using MspI enzyme showed that the tick’s salivary glands were negative to Theileria lestoquardi infection. CONCLUSIONS: Based on the results, it is concluded that Theileria annulata and Hyalomma a.anatolicum are important agent and vector tick of tropical theileriosis in dairy cattles of Yazd area.

CASE HISTORY: Equine coital exanthema caused by Equine herpesvirus 3 (EHV3) was reported in 1900. At the present time, it has become epidemic among horses. The virus could be transmitted via insemination, iatrogenic, and it basically infects the squamous epithelium of the epidermis. CLINICAL PRESENTATION: In the first week of January 2012 two mature male horses and a mare were imported from Netherland and kept in a stable of a horse riding club located around Tehran. In the first week of December, these animals manifested clinical signs of high fever with repeated intermittently for two times. During this period, one of the male horses developed exanthematous lesions on the penis and perinea tissues which depigmented later. Biopsy specimens obtained from the lesion processed for histopathological examination were stained with Harris H α E and nuclear fast Red methods. DIAGNOSTIC TESTING: Microscopically, ballooning degeneration of squumous epithelium, acantholysis, epithelial ulcers accompanied by multiple bacterial colonies and the herpes virus intranuclear inclusion bodies with margination of nuclear chromatin were evident. Obviously the horse had EHV3 infection and the stresses resulted from high fever led to the reappearance of genital exanthematous lesions. ASSESSMENTS: In spite of the contagious nature of the infection, the native horses kept in the same stable did not manifest any clinical sings of the infection and therefore the disease could be native. Since the EHV2 infection first affects upper respiratory infection with a high fever course and then induces viremia with another high fever period so it might be speculated that the primary disease of the Netherland horses caused by the EHV2 infection.

BACKGROUND: Despite the use of prophylactic chemotherapy and vaccination, coccidiosis is still one of the most devastating diseases in poultry industry. Understanding the immune mechanism helps researchers to prevent this parasitic infection more effectively. OBJECTIVES: The purpose of this study was to evaluate the antibody response in chickens, induced by a live attenuated vaccine (Livacox Q), before and after challenge, by means of ELISA. METHODS: One hundred and twenty one-day-old male Ross 308 broiler chicks were randomly divided into 4 groups of 30 birds. In 4th day of age, half the birds were orally vaccinated. The challenged groups received the infective dose at 14th day of age via oral administration. Besides recording weight gain, lesion score and oocyst count in 21st day old birds, humoral immunity was assessed by means of ELISA on serum samples taken from 7 and 21day-old birds. Results: Three days post vaccination, the average of optical density (OD) showed significant difference between vaccinated (0.553) and unvaccinated (0.686) birds (p≤0.05). In 21 day-old birds, the OD of unvaccinated-unchallenged (negative control) groups (0.331) differed significantly with vaccinated-unchallenged (0.663) birds. The average of lesion score in vaccinated-challenged birds (2.22) showed significant dissimilarity with unvaccinated-challenged groups. No difference and correlation were observed in comparing average of weight gain and oocyst count with serum optical density among treatment and control groups. ConclusionS: The results indicated that ELISA can be used for evaluating immunity uniformity of a flock after vaccination. Besides inducing antibody responses comparable to challenge with wild oocysts, vaccination with live attenuated coccidiosis vaccines may have inhibitory effects in intestinal lesion scores which are responsible for pathogenesis and economic loss during coccidial infections.

BACKGROUND: Considering the difference between the rate of multiple ovulation and ovarian activities of different breeds of ewes in different regions, especially out of seasonal breeding condition, finding efficient and effective protocols to induce multiple ovulation out of seasonal breeding would be much appreciated. OBJECTIVES: This study was conducted to determine fertility and multiple ovulation rates during summer and investigate the effect of supplementary feeding, and eCG injection prior to mating in the reproductive performance of Zel ewes. METHODES: At the beginning of summer, 135 ewes in Savadkooh region (north of Iran) were randomly selected and divided into six groups. The estrus cycles of ewes, except in control groups, were synchronized using a vaginal sponge for 14 days. In groups 1 (n=22) and 2 (n=22) ewes were fed with supplementary feeding for 21 and 8 days, respectively, prior to mating. In Group 3 (n=26) ewes were fed with the same ration as Group 2 and were injected (IM) with 400 IU eCG at the time of sponge withdrawal. Ewes in Group 4 (n=23) just grazed on the pasture and injected with eCG as Group 3. In Group 5 (n=20) the estrus of ewes was synchronized as other groups, but they were not received any other treatment. Ewes in Group 6 (n=22, Control) received no treatment, and as the same Group 1 and 2 were mated with fertile rams for eight weeks. Experimental ewes were mated with fertile rams (1:8) 48 hrs after sponge removal for 96 hrs. RESULTS: The findings showed that the fertility in group 3 was significantly more than group 2 and 5, but there was no significant difference between the others (p>0.05). The prolificacy and fecundity were significantly higher in groups treated with eCG than the others (p<0.01), however there was no significant difference between groups 3 (with flashing) and 4 (without flashing). CONCLUSIONS: It could be concluded that vaginal sponge and eCG treatment may improve the multiple lambing and reproductive performance of Zel ewes during summer, and supplementary feeding prior to mating, as described in this experiment, cannot make any significant improvement in multiple lambing.

BACKGROUND: Heat stress declines the performance through physiologic changes of the poultry. OBJECTIVES: This experiment was conducted to evaluate the effects of different levels of L-carnitine on performance, carcass characteristics and some blood parameters of broiler chickens fed with high fat diets under heat stress. METHODS: Two hundred one-day-old broiler chicks (Ross 308) were used in a completely randomized design by four treatments and five replicates (pen) 10 birds in each replicate. The chickens of experimental treatments were fed with basal diet (control group) and the diets plus the different levels of 100, 200 and 300 mg/kg L-carnitine. The experimental diets were used during the finisher period (day 24 to 42 of age) and under heat stress (32±1ºC as cyclic from 9.00 AM to 5.00 PM). RESULTS: The results showed that the chicks fed with the highest L-carnitine had the higher weight gain during the finisher period as compared to control and the lower L-carnitine fed chicks (p<0.05). Furthermore, the feed conversion ratio of birds fed with the medium and high L-carnitine levels (100 and 300 mg) was lower than that of control birds (p<0.05). In orthogonal contrasts, L-carnitine supplementation caused the improvement in weight gain and feed conversion ratio during both the finisher and whole experimental periods (p<0.05). The consumption of highest L-carnitine decreased the abdominal fat as compared to control (p<0.05). In orthogonal contrasts, L-carnitine consumption caused the higher glucose and lower abdominal fat in comparison to control (p<0.05). CONLUSIONS: Totally, the results of recent experiment show that consumption of 300 mg/kg L-carnitine improves the performance of broiler chickens through the increase in dietary fatty acids and energy.

BACKGROUND: The use of feed withdrawal for molt induction can negatively affected the structure and microbial environment of intestine and lead to greater intestinal colonization by salmonella infection. OBJECTIVES: The aim of the present experiment was to determine the effects of alfalfa as a high fiber ingredient for molt induction on intestinal morphometric characteristics and performance of commercial laying hens. METHODS: In this experiment 108 Hy-line (W36) laying hens aged 74 weeks in a completely randomized design with 3 treatments and 6 replicates were used. Using treatments for 12 days molt period were included: 1- control group fed with layer ration (FF), 2- feed withdrawal group (FW), 3- group fed with 90% alfalfa and 10% layer ration (A90). Performance of birds was monitored for 12 weeks after the end of the molting period. RESULTS: Feed withdrawal hens had lowest villus height in all three regions of the intestine (p<0.05).The highest average of deudenal crypt depths was observed in FW hens. In all three regions of the intestine, the lowest amounts of villus index and villus surface was observed in FW hens (p<0.05). In all three regions of the intestine, the highest and lowest average of goblet cells was seen in the A90 and FW hens respectively. The highest mean of post molt egg mass was observed in FW hens (p<0.05). The best FCR was seen in the A90 group. CONCLUSIONS: The use of alfalfa-riched feed for molt induction of laying hens results in improvement of morphometric characteristic of intestine and post molt performance.

BACKGROUND: AmpC and ESBLs as mediated-plasmid extended spectrum β-lactabases are the main factors of resistance to extended-spectrum cephalosporins in enterobacteriacea especially E. coli and will follow treatment failure, high costs of treatment in human and economic losses in the poultry industry. OBJECTIVES: The purpose of this study was to screen and study the faecal E. coli isolates producing extended spectrum β-lactamases (ESBLs) and AmpC enzymes and related workers. METHODS: A total of 500 cloacal swab samples from broiler chickens and 25 rectal swab samples from workers were collected from five poultry houses around Tehran. All samples were seeded on MacConkey agar and identification of E. coli isolates were performed via biochemical tests. Antibiotic susceptibility was determined against 12 antibiotics using the disk diffusion method as recommended by the clinical and laboratory standard institute (CLSI2012). Ceftazidim / ceftazidim-clavolanic acid and cefoxitin / cefoxitin-EDTA disks were used for the detection of ESBL and AmpC phenotypes, respectively. phonetic analysis of the drug resistances was performed via SPSS software and Chi-square test. ESBL- producing E. coli screened by PCR for the presence of genes encoding beta-lactamases of TEM, CTX-M and SHV.       RESULTS: A total 467 E. coli isolates were isolated from 88.9% of the samples as 92% and 72.7% of isolates presenting MDR phenotype among chickens and workers respectively. ESBL phenotype detected in 5.5% (26) of poultry isolates while, none of the workers isolates have this phenotype. Six isolates carried both of TEM and CTX-M whereas, five and one isolates were detected only for TEM and CTX-M, respectively. Eighty-eight and nine-tenths percent of ESBL E. coli displayed AmpC phenotype. CONCLUSIONS: Since cephalosporins are not used in broilers in Iran, isolation of faecal E. coli isolates producing extended spectrum β-lactamases in broilerchickens can indicate transfer of the resistance genes via plasmids and other mobile genetic elements among Enterobacteriaceae.

BACKGROUND: Brucellosis is one of the most common zoonosis in Middle East and Iran. OBJECTIVES: The purpose of this study was genomic detection of Brucella spp. in sero-positive dairy cattle. METHODS: We have collected 28,519 blood samples from cows during 2012-2013. Samples were screened by Slide and tube agglutination and 2-Mercaptoethanol tests. Samples with anti-Brucella antibodies titer ≥ 1:80 and ≥1:40 in tube agglutination and 2-ME tests were considered as positive respectively. Tissue samples include: lymph nodes, liver, testicle and kidney from 122 samples of slaughtered cows were collected. The Sero-positive samples were examined by a collection of specific primers for Brucella abortus, Brucella melitensis, vaccinal strains included RB51 and Rev1 using PCR tests. RESULTS: Results showed that 450 samples were positive in slide agglutination test and 447 samples had anti-brucella antibodies titer equal to or more than 1:80. So they were positive by tube agglutination test. Three hundred eighty nine samples were positive by 2- mercaptoethanol test. PCR test results showed that 46 samples (37.7%) out of 122 samples had a specific sequence of Brucella or otherwise they have an active infection with Brucella species, whereas 62.3% of samples were negative. The PCR results showed that 2 samples (4.35%) were infected by B. melitensis, 2 samples (4.35%) infected by Rev1 strain and 42 samples (91.3%) were infected by B. abortus. CONCLUSIONS: The results showed that, as we had expected, the majority of cows were infected by B. abortus. Animals who infected by B. melitensis and Rev1 strain may be a result of contact with sheep or goats. We couldn’t find Brucella genome in 76 samples (62.3%) of sero-positive cows. It may be caused by cross reaction of sera with Brucella species in tests or activation of immune system response and elimination of organism from internal organs.

BACKGROUND: Freshwater pulmonate family Lymnaeidae are well-known for their role in transmission of diginean trematodes worldwide. Objectives: The study was aimed to investigate the ecology and effects of physical and chemical components of the environment on their distribution and populaion density. Methods: The lymnaeid snails were randomly collected from 16 freshwater habitats in West Azarbaijan Province and water samples were also provided from the habitats for chemical analysis. Results: The distribution patterns of the lymnaeid snails in all the examined sites were almost identical throughout the year except in winter. The snails were mostly found in lentic waters or slow-moving streams with muddy beds. The population densities of Lymnaea auricularia, L. gedrosiana and L. stagnalis significantly differed among the investigated waters during the course of study. The concentration of nitrate had significant positive correlations with the snails’ density while there was no significant correlation between nitrite or phosphate concentration with the population density and body size. Conclusions: The results indicated that distribution and density of the snails were affected by season and physicochemical characteristics of environments. These results can be useful for launching the control programs against parasitic trematodes in the region.