BACKGROUND: K99 pilus antigen is one of the major adherence factors found on enterotoxigenic Escherichia coli (ETEC) of neonatal calves. It causes severe diarrhea in newborn calves via the production of heat-stable enterotoxin (STa).With increasing concern over the spread of antimicrobial resistance, the development of alternative to conventional antibiotics such as colicin is urgently needed. Colicin is an antimicrobial peptide produced by one strain of E. coli to suppress the growth of other strains of E.coli. Objectives: The purpose of this study was to investigate the control of E.coli k99 and the efficacy of colicinogenic E.coli (CEC) in adult mice. Methods: The mice, used antibiotic were divided into four groups. The first group did not receive any inoculation. The second group was fed just with 0.5 ml colicin solution. The third group was fed just with 0.5 ml E.coli k99 suspension. The fourth group was first fed by 0.5 ml E.coli k99 suspension immediately after oral administration of CEC suspension. Fecal samples of mice in four groups were taken 1, 2, 3, 4, 5, 6 and 7 days after inoculation and colony forming units (CFUs) were monitored per gram feces. ResultS: The results showed that CEC has inhibitory effect against E.coli k99. There were observed significant differences between the amounts of E.coli k99 recovered from the feces of mice in fourth group with the amount of E.coli k99 recovered from the feces of mice in third group. Conclusions: The data presented here support this claim that CEC plays a significant role against E.coli k99. Furthermore, the study suggested colicin warrants further evaluation as a potential alternative to conventional antibiotics for use to control of E.coli k99.

BACKGROUND: Sheep are a form of investment and a quickly liquidatable resource, particularly in traditional and low income production systems. Tropical and long warm-season regions always affect sheep production negatively. Methods: In this experiment 15 female and 7 male sheep were chosen and their body temperature, heart rate, respiration rate measurements and blood sample for biochemical parameters analysis were taken during May 5 to September 5. Results: Heart rate and respiration rate in male sheep were a little higher compared with female sheep but there was no significant difference between them respiration (56 vs. 55) and beat (120 vs. 118 per min). Rectal temperature wasn’t significant between two sexes (40.6-40.09 C˚). Also skin temperature wasn’t significantly different between two sexes (36.02- 36.08 C˚). The only difference was related to month effect (p<0.05). Sex and month hadn’t significant different effects on blood urea, creatinine, glucose and potassium concentration. Blood urea concentration of female sheep was not significantly higher than male’s (p>0.05). Blood Sodium concentration was significantly different between two sexes so that male sheep had the highest minimum average (p<0.05). There was no significant increase in blood Potassium concentration of female sheep compared to male sheep (p>0.05). ConclusionS: These results indicated that sheep of this region had been well adapted to summer heat stress and they showed usual changes of blood metabolites in response to heat stress.

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: One of the most important heart diseases in dogs is valvular insufficiency, which can be evaluated by diagnosis ways such as phonocardiography, echocardiography, etc. OBJECTIVE: The purpose of the current study was to evaluate of valvular insufficiencies with phonocardiography and echocardiography and using phonocardiography technique in detection of cardiac valvular disease in practice. METHODS: This survey was done on 180 five-year-old dogs which 30 of them had valvular insufficiency. They have been referred to radiology section and echocardiography technique was used after listening to heart sounds and recording heart murmur and surveying by phonocardiography. The type and location of valvular insufficiency was diagnosed by phonocardiography and then echocardiography was used, the results from both techniques was compared afterwards. RESULTS: In all of these 30 dogs, murmur was systolic and mitral insufficiency and mitral regurgitation were diagnosed by phonocardiography. using echocardiography, the mitral insufficiency was confirmed in 28 dogs, one of them has been diagnosed to have tricuspid inssufiency and pulmonary stenosis in addition to mitral insufficiency. In two cases no abnormality sign has been detected. CONCLUSIONS: According to this study, it is recommended to use phonocardiography technique in order to pre-diagnose the valvular insufficiency, it's type and location and use echocardiography to determine the process of disease and control this progress.

BACKGROUND: Adiponectin is one of the most important adipocytokines that regulate male and female fertility via AdipoR1 and AdipoR2 receptors. Recently expression of adiponectin system and its negative regulatory role on hypothalamus-pituitary axis have been confirmed. Objectives: No information is available about the expression pattern of adiponectin and its receptors in hypothalamus-pituitary axis in domestic animals. Here for the first time, we studied hypothalamus-pituitary adiponectin system gene expression in different stages of bovine estrous cycle. Methods: Anterior pituitary and hypothalamus were collected from Holstein cow at the local abattoir. The estrous cycle was classified to four phases (proestrous, metstrous, early luteal and late luteal) based on macroscopic examination of ovaries and uteri. Gene expression analysis of adiponectin and its receptors was done using quantitative real time PCR (qPCR Probe MasteKit) and according to the comparative 2-ΔΔCt method. E2 and P4 levels were measured using ELISA method. Results: Our results demonstrated that adiponectin and its two receptors were expressed in pituitary and hypothalamus of cyclic cow. Maximal expression of adiponectin was observed in early luteal phase, while it was expressed at minimal level during the proestrous stage. We observed no significant changes in the expression of AdipoR1 in both tissues at different stages of estrous cycle. The highest expression of AdipoRII in both tissues was detected during the proestrous stage, while it expressed at minimal level during the late luteal phase. E2 and P4 had respectively negative and positive correlations with adiponectin expression levels in hypothalamus and pituitary. Conclusions: Based on our results that demonstrated adiponectin was minimally expressed at proestrous stage and other data about the negative action of adiponectin on LH secretion from pituitary, we concluded that adiponectin may has role in the hormonal function of this axis during the estrous cycle.

BACKGROUND: High grain diets in ruminants increases the risk of digestives disorders such as acidosis which may lead to high economic loss. OBJECTIVES: This experiment was conducted to determine the effects of an unsaturated and polyunsaturated fatty acid and monensin on gene expression of enzymes involved metabolic pathway of cell proliferation and rumen epithelial intracellular pH regulation. METHODS: Twenty two male Afshari lambs with live body weight of 45 ± 8 kg and six month age were used in a completely randomized design with 3 treatments replicates for 77days including 21 days adaptation period. Experimental diets were consisted of a basal high concentrate diet (16% CP and 2.75 Mcal/kg ME) and 1) no additive (control, C= 8 lambs), 2) 30 mg monensin/day/head during the whole experimental period (T1= 8 lambs), and 3) (polyunsaturated fatty acidduring the whole experimental period (T2 = 6 lambs). Lambs were killed after 77 days on the treatment diets. RESULTS: Compared with the C treatment, relative abundance of mRNA of monocarboxylate transporter isoforms MCT1, MCT4 and the ketogenic enzyme 3-hydroxy-3 methyl-glutaryl CoA-synthase (HMGCS2) were higher for the T1 treatment. The expression of cholesterolgenic enzyme HMGCS1 was down-regulated for the T1 treatment and that of HMGCS1 was up- regulated for the T2 treatment. The expression of MCT1 and MCT4 were down-regulated for the T2 treatment. Monensin had an additional impact on the mRNA abundance of epithelial SCFA- and acid-base transporters with concurrent changes in rumen epithelial thickness. CONCLUSIONS: The results suggest that adding monensin and oil as nutritional means to reduce acidosis cause changes in mRNA expression of VFA transferring proteins and limiting enzyme in the synthesis of cholesterol and Ketone bodies in the rumen epithelium.

BACKGROUND: Probiotics, in form of microbial supplements, are known to be a suitable alternative for antibiotics and can affect the health indicators of host. Objectives: The present study was conducted to assess the combined effects of dietary autochthonous Saccharomyces cerevisiae and Aspergillus niger on haematological and serumbiochemicalparameters of beluga sturgeon (Huso huso) juveniles. Methods: This study was based on a completely randomized design with 4 treatments and 3 replicates on beluga juveniles with average weight of (mean ±SE) 31.8±2.81g. Beluga Juveniles were divided randomly into 12 fiber glassy tanks with density of 30 fish per tank and were fed with diet contain dietary probiotic with density of 2×106 (Cells/g) for the first treatment, 4×106 (Cells/g) for the second treatment, 6×106 (Cells/g) for the third treatment and basal diet without probiotic for the control group for 8 weeks. Results: Diet supplementing with concentration of 6×106 (Cells/g), significantly improved serum biochemical parameters (p<0.05), however hematological parameters were affected by supplemented diet with probiotics that showed no significant difference in comparison with the control group (p>0.05). Also results indicate that growth factors were improved in experimental treatments in comparison with the control group. Conclusions: The results showed that the use of combination of these species with studied concentrations can improve the performance of some biochemical parameters such metabolites factors, immune, enzymes and serum electrolytes of belugajuveniles. It is recommended that the concentration of A. niger and S. cerevisiae, used for third treatment be used as an immune stimulator for beluga juveniles.

BACKGROUND Honey bee venom contains complex compounds such as polypeptides, enzymes, and amines. One of the important components of bee venom is the phospholipase A2 enzyme, which is considered an important honey bee venom allergen and is also used to treat some diseases. This enzyme is found in other insects, arachnids, snakes, and mammalian cells, and its function is the hydrolysis of the second ester bond of glycerophospholipids and the release of fatty acids and lysophospholipids. Although transient transfection can produce recombinant proteins, stable cells are more suitable for high-scale production with economic efficiency.OBJECTIVES: The present study created a stable cell line to produce recombinant phospholipase A2 from honey bee (Apis mellifera) venom.METHODS: Plasmid cloning DNA vector containing phospholipase A2 gene was prepared by Macrogen Company. The recombinant plasmid was transferred to Chinese hamster ovary cells by heat shock method, and gene expression was carried out in a HamsF12 culture medium containing neomycin antibiotic. After increasing polyclonal strains containing plasmid, monoclonal clones were selected by limiting dilution. Then, monoclonal clones were propagated, the soup of the selected cells was collected and concentrated, and the protein expression was checked by sodium dodecyl-sulfate polyacrylamide gel electrophoresis test.RESULTS: The results of electrophoresis, which was performed to confirm the expression of the phospholipase A2 gene in the cell soup, showed a band with a molecular weight of 20 kilodaltons, which confirms the creation of a stable cell line for the production of recombinant phospholipase A2 honey bee venom.CONCLUSIONS: After the transient transfection of the plasmid containing this gene, several cells undergo recombination due to having repair mechanisms and putting the desired gene along with the antibiotic resistance gene in their genome. These cells can be selected and propagated by adding antibiotics to the culture medium.

BACKGROUND: Toxocara canis is a zoonotic disease that commonly infects canids. Mammals and birds are sometimes infected with this disease as paratenic hosts. It can also cause accidental infection in humans. The increase in the number of stray dogs, the expansion of urban gardens, and the proximity of dogs to humans increase the risk of human infection with Toxocara canis.OBJECTIVES: This study aims to determine the prevalence of Toxocara canis infection in dogs and foxes in Zanjan province, Iran.METHODS: A total of 484 fecal samples of stray dogs (n=355), rescue dogs (n=49), guard dogs (n=50), and foxes (n=30) in Zanjan were randomly collected from June 2021 to February 2022. The microscopic examination was done following formalin-ethyl acetate sedimentation procedures. Finally, the PCR method was used to confirm the presence of Toxocara canis in positive samples.RESULTS: Microscopic study revealed that, out of 484 samples, 21 (4.3%) were positive for Toxocara/ Toxascaris eggs. Between these positive samples of dogs and foxes, only 6 samples from dog feces were confirmed as a Toxocara canis infection by the PCR method.CONCLUSIONS: There is an increase in the prevalence of Toxocara canis infection in stray dogs in Zanjan, Iran. Given the presence of dogs in parks and residential areas, there is a risk of human infection with Toxocara canis, emphasizing the importance of adhering to treatment and prevention protocols in dealing with stray dogs.