BACKGROUND: The modern dairy cows, due to intensive selection for higher milk production during past decades, have become more resistant to insulin. Accompanied with DMI depression in per parturient dairy cow, insulin resistance may lead to a massive release of non-esterified fatty acids (NEFA) to bloodstream which might act as a start point for development of other diseases. OBJECTIVES: The purpose of this study was to investigate potentiality of long chain polyunsaturated fatty acid (LCPUFA) of marine or polyunsaturated fatty acids (PUFA) of plant origin to correct the insulin resistance induced by saturated fatty acids in cultured bovine adipocytes. METHODS: Fatty acids from different oils were isolated using KOH and were mixed together with different proportions to obtain the following profiles: 1) saturated fatty acids (SFA); 2); saturated fatty acids+n-6/n-3 PUFA (medium chain) at ratio of 1:1 (SFA-MC1:1)and3) saturated fatty acids + n-6/n-3 PUFA (long chain) at ratio of 1:1 (SFA-LC 1:1). Adipocytes were cultured for 48 in the presence of treatments and after the incubation period an epinephrine challenge was applied to stimulate lipolysis. In the adjacent culture plates for each treatment insulin was added along with epinephrine challenge in different concentrations to test sensitivity of adipocytes to insulin. After conducting insulin sensitivity test, a sample was taken from culture media and analyzed for glycerol concentration as an index of lipolysis. RESULTS: Results indicated that saturated fatty acids effectively induced insulin resistance in adipocytes. Long chain polyunsaturated fatty acids from fish oil had a significant preventive effect on insulin resistance induced by saturated fatty acids so that increasing insulin concentration linearly increased the response of adipocytes to insulin in treatment LC-SFA 1:1. Shorter chain n-3 polyunsaturated fatty acids of plant origin did not show such effects on insulin sensitivity in adipocytes. ConclusionS: n-3 fatty acids from fish oil improved bovine adipocyte sensitivity to insulin but shorter chain n-3 fatty acids did not show this ability.

BACKGROUND: In recent years, many studies have been conducted on finding a suitable replacement for fish meal to supply the needs of aquaculture feed industry. Objectives: The present study was performed to examine the effect of replacing fish meal and fish oil with plant sources on bacterial counts in intestinal contents and mucus and bacterial composition in Beluga sturgeon. Methods: Beluga sturgeons with a mean initial weight of 133±5 g were distributed into 18 (300 L) tanks (30fish/tank) and were fed experimental diets for 60 days. The control diet contained only fish meal and fish oil as the primary source of protein and lipid, while the experimental diets contained 0, 40, 60, 80 and 100 percent plant protein sources (wheat gluten, corn gluten and soybean meal) and 20% vegetable oil blend (canola, sunflower, cotton and safflower oils) respectively. Results: Results showed that replacement of 80% fish meal and fish oil with plant sources didn’t have significant effect on final weight (235 ± 17 g) compared to control group (256.1 ± 10 g) in a 60 days trial. Replacement of fish meal with 100% plant proteins in combination with 80% vegetable oils resulted in significantly lower final weight (225.7 ± 11 g), compared to other treatments including control group (p<0.05). Replacing 80% fish oil with vegetable oils resulted in a significant reduction of bacterial count in intestinal contents and a significant increase in percentage of Entrobacteriacea sp. However, no significant differences were detected in bacterial counts of mucus in experimental treatments compared to control (p>0.05). Replacement of 60, 80 and 100% fish meal and 80% fish oil with plant sources significantly decreased bacterial counts in intestinal contents and intestinal mucosa compared to control group (p<0.05). Also this replacement cause significant change in bacterial composition of intestine. Conclusions: The results suggested that using plant sources in juvenile Beluga sturgeon diet decreases the bacterial count in the intestinal contents and mucus and changes the composition of intestinal micro flora.

BACKGROUND: Dietary nucleotide has been shown to improve growth indices, nutritional function and higher vertebrates in fish. OBJECTIVES: We investigated the effect of different levels of dietary nucleotide on growth parameters, whole-body composition and fluctuations of cortisol and glucose due to acute stress in Snow trout (Schizothorax zarudnyi). METHODS: One-hundred-twenty Snow trout fingerlings with average weight 7.58±0.05g, were fed with four levels of dietary nucleotides including 0 (control), 0.15, 0.25, and 0.5 percent for 8 weeks. Ten fingerlings were stocked into each 300l tank with triplicate in four treatments and fed three times daily at 3-5% body weight rate. At the end of feeding trial, weight gain, Weight gain rate, feed efficiency, Food efficiency ratio and survival were computed. Also, the numbers of fish that were exposed to acute stress (temperature and pH). RESULTS: The results showed that none of the nucleotide-supplemented diets had any significant effect on growth indices (p>0.05). None of the dietary treatments resulted in any significant changes to dry matter, ash and protein. The only significant difference was observed in the fat (p>0.05). The fish fed 0.25% nucleotide showed higher whole lipid compared to other dietary treatments. Stress test results showed no significant difference at the beginning of the experiment, whereas after, acute stress cortisol levels were significantly higher in trials. The lowest response was observed in trial with 0.50% nucleotide and the highest was in control groups. Glucose levels were not significantly different, neither before nor after acute stress. CONCLUSIONS: The nucleotide composition used in the present study failed to provide significant effects on growth of Snow trout juveniles but could improve response to acute stress.

BACKGROUND: Vitamin A is a lipid soluble vitamin which can be stored in the body organs (especially in liver) and its supply is only through ration. Objectives: The present study has been conducted to evaluate vitamin A status of feedlot cattle in the city of Garmsar and impact of season and nutritional management on it. Methods: During the study 100 blood samples were taken from feedlot cattle of 6 farms in cold seasons of one year and 100 samples from 5 farms in warm seasons of the same year. Also, 50 blood and liver samples of slaughtered feedlot cattle were taken from Garmsar slaughter house in each of the mentioned seasons. Serum and hepatic tissue concentrations of vitamin A and beta carotene were measured by using standard biochemical methods. Student’s t-test and Tukey’s HSD tests were used for analysis  of the results and  pResults: The results of present study showed that mean serum and hepatic concentration of vitamin A in feedlot cattle in the city of Garmsar was in defined normal range for cattle and these animals did not show any vitamin A deficiency, but mean serum beta carotene concentration was at a very low level and lower than defined normal range for this species. Mean serum vitamin A concentration of feedlot cattle in cold seasons was significantly higher than that in warm seasons (p<0.05), conversely serum beta carotene concentration of feedlot cattle during warm seasons was significantly higher than that in cold seasons (p<0.05). However, comparing vitamin A concentration of liver tissues of feedlot cattle in cold and warm seasons did not show any significant difference (p>0.05).  ConclusionS: From the results of the present study it can be concluded that serum and hepatic concentration of vitamin A in feedlot cattle of the city of Garmsar was in normal reference range of cattle, and in spite of very low concentration of serum beta carotene concentration, due to supplementation of this vitamin in feed, vitamin A deficiency did not occur in these cattle.

BACKGROUND: Mastitis is an important health disorder in dairy herds which affects milk production, animal reproduction and production. OBJECTIVES: The aim of this study was to estimate the cumulative incidence of mastitis in dairy herds in Tehran province.  METHODS: From 679 dairy herds in Tehran province that have more than 50 animals, 32 dairy herds were selected randomly and animals that had calved from March 2007 to March 2008 were followed until the next calving or culling. In total 10506 animals were included in the study. The information on number, parity, occurrence of mastitis was gathered from registry forms. RESULTS: Cumulative incidence of mastitis in this study was calculated 35.8% (95% Confidence interval (34.9-36.8), 3764 animals of 10506). Incidence of mastitis was increased by the increasing parity of animals, and animals in fifth parity have the most incidence. CONCLUSIONS: The results of this study showed the incidence of mastitis in this area is very high and it is necessary to control it.

BACKGROUND: Atrazine is one of the most important and effective pollutants in aquatic ecosystems. The widest sugar cane farms of the Middle East are located in Khouzestan province, Iran. Large amounts of Atrezine are being used in farming on these farms.                  Objectives: The aims of this study were to investigate acute toxicity (LC50 96 h) of atrazine on Barbus grypus and the effects of chronic toxicity with sub-lethal concentration of atrazine on hematological parameters as well. Methods: 180 B grypus were divided into 4 equal groups (5, 10 and 20% of LC50 96 h and control). Blood samples were taken on days 0, 7, 14 and 21 of experiment. Hematological parameters including hemoglobin level, hematocrit, and red blood cells (RBC), white blood cells (WBC), and globular indices were measured and compared among the groups. Results: LC50 96 h was measured 65 mg l-1. Hematological parameters were  significantly affected by chronic toxicity of atrazine. Hemoglobin, hematocrit and RBC were decreased at all sampling periods in fish exposed to different levels of atrazine (p<0.05). There were no significant changes in globular indice values among the groups in sampling periods (p>0.05). For all samples, WBC value was decreased significantly on day 21 (p<0.05). Conclusions: Based on the results, it can be concluded that chronic atrazine toxicity adversely affects hematological parameters of B. grypus.

BACKGROUND: Lactoperoxidase is an enzyme of the oxidoreductase family. Lactoperoxidase is an important antimicrobial agent. Applications of lactoperoxidase are being found as a preservative in food and cosmetics. Immobilized LPO provides several significant benefits such as: easily separated from the reaction products, reducing production costs by efficient recycling and control of the process. Objectives: Purification and immobilization of lactoperoxidase extracted from camel milk using sodium alginate polymer. Methods: The lactoperoxidase was purified from camel milk by using sephadex G-100 gel filtration CM and sephadex C-50 ion-exchange chromatography. Encapsulation was carried out by using LPO, sodium alginate, glycerol and Tween 80. Afterward, the microcapsules were stablized by calcium ion (1%). Efficiency of encapsulation was calculated. The particle size and distribution were measured with particle size analyzer. Morphology and formation of the particles were studied  using Scanning Electron Microscope (SEM). Stability of encapsulated and uncapsulated  LPO was studied at 4 °C during 70 days. Results: After purification and purity measurement by SD-SPAGE, concentration of 0/28 micrograms per liter for each of the fractions was obtained. Microencapsulation efficiency was 84% and microcapsules  less than 200 nm were formed. Observation by SEM confirmed the formation of microparticles. Microcapsules have a relatively smooth surface, spherical with low tenacity as well. Stability of encapsulated enzyme at 70 days was obtained 81%. Conclusions: Immobilization of Lactoperoxidase extracted from camel milk  using sodium alginate is a good method to increase performance of the enzyme.

BACKGROUND: Staphylococcus aureus (S. aureus) possess a variety of virulence genes that are involved in the pathogenesis of infections caused by this agent. OBJECTIVES: The aim of this study was to evaluate the prevalence of the genes encoding collagen binding (cna) and fibronectin binding (fnb) adhesion factors in Staphylococcus aureus isolates from food and clinical specimens. METHODS: During the time period 2010-2013, a total of 38 isolates of Staphylococcus aureus from clinical specimens and 32 isolates from food samples were collected. All isolates were identified biochemically and subjected to DNA extraction. The accuracy of DNA extraction from each isolate was confirmed by PCR amplification of aroA gene and then the presence of cna and fnb genes in the extracted DNAs was assessed by PCR, using the specific primers. RESULTS: The results showed that among 38 isolates from clinical specimens, 15 (39.5%) &amp; 32 (84.2%) and among 32 isolates of food origin 10 (31/2%) and 16 (50%) isolates had cna and fnb genes respectively. Thirteen clinical (34.21%) and 6 food isolates (18.7%) were positive for both fnb and cna genes and 4 clinical (10.5%) and 12 food isolates (37.5%) were lacking both genes. CONCLUSIONS: According to the results, it is concluded that, although these adhesion genes are not present in all Staphylococcus aureus clinical isolates, but their prevalence is high and using the products of these genes in vaccines may be effective in protecting against infections caused by this bacterium.

BACKGROUND: Poultry production in houses and high stocking density, results in                increase in mortality because of different diseases. Objectives: Investigating the effective managerial and environmental factors on mortality in industrialized poultry farms, proportion of each factor and ranking farms based on mortality risk to solve some problems of Iran’s poultry farm insurance. Methods: Samples were taken from 47 broiler, 20 layer and 30 broiler breeder farms of 16 Iranian provinces which were selected based on geographical location, climate and outbreaks of diseases. House characteristics were evaluated by precision measurement. Parameters such as heat exchange, light intensity, atmospheric conditions (inside oxygen and ammonia concentration, acidity and moisture of litter) and quality of equipment (ventilator capacity, heating &amp; cooling systems) were measured. Based on collected data,  managerial index was defined and calculated. Parameters related to sanitary condition, birds’ health and immunization were measured by blood anti body titer. A total of 97 poultry farms were included in the investigation and 27231 measurement data were recorded. Results: Average mortality in broiler, layer and breeder farms was 15.4, 11.2 per period and 1.9% per month, respectively. According to stepwise minimum Wilk’s Lambda discriminant regression, the highest standardized coefficient belonged to vaccine accomplishment (VA) followed by house ventilator capacity (VM), immunization against avian influenza (AIG), farm biosecurity (SHOW), drinker type (DRIN), precipitation rate (RAIN) and temperature management index (TMI): Mortality Risk(0,1)=-2.622+1.533 VA-1.135 SHOW+0.739 AIG+0.551 DRIN-0.016 VM+0.003 RAIN+0.002TMI. Main variables of models which were fitted to layer and broiler breeder flocks were health and ventilation. Conclusions: 6 managerial and environmental factors, immunization of flock against diseases, farm biosecurity and house ventilation had the greatest impact on ranking the mortality risk.

BACKGROUND: Mycoplasmosis is an infectious disease of poultry and a major cause of economic losses due to decline in growth, egg production, reduction in egg hatching and exacerbation of viral and bacterial respiratory diseases. Objectives: The purpose of this study was detection of serological prevalence of Mycoplasma gallisepticum infection in broiler breeders of Mazandaran province and to suggest control strategies against mycoplasmosis. Methods: All breeder farms that were in production period in Mazandaran province were sampled (74 farms in 14 cities); blood samples were collected from 45 birds in each farm. Sera samples were examined by RSPA and ELISA tests based on the instructions of OIE. Results: In this study, by the RSPA test, 3 out of 74 farms (4%), 15 out of 553 houses (2/7%) were positive. From 5626 collected sera samples, 139 samples (2.5%) were positive in RSPA and 124 samples (2.2%) in ELISA. Conclusions: Seroprevalence of MG infection was 4% during the selected period and zone of study.  Statistical analysis showed that biosecurity situations were significantly better in negative farms (p=0.04). There are some deficiencies in quality of biosecurity situations despite  implementing biosecurity principles in farms. Establishing of farms near villages or the development  of villages, keeping backyard birds close to the farms and employees living in villages are some of the  biosecurity principles that were not followed in infected farms.