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: Heat stress is very important in poultry production. OBJECTIVES: To evaluate the effect of oral elatoninsupplementation and increasing of dark period on biochemical profile of broiler chickens under Heat Stress (HS). ETHODS: A total of 200 day- old broiler (Arian) chicks were randomly allocated in to 4 groups (dark ,melatonin, negative and ositive controls). Melatonin group  received 40 mg melatonin/kg  diet from 30-40 days of age and chickens of dark group were xposed to  a  special lighting schedule from 10-40 days of age. All groups (except negative control) were daily exposed to HS (39± 1 c) for 6 hours per day from 35-40 days of age. At the end of 6 weeks, body weight was measured. At 30, 35, and 40 days, serum uric acid, glucose, total protein, albumin, globulin, activity of AST  and creatinine were measured.  atawas analyzed by ANOVA and Tukey test in SPSS software. RESULTS: In 30 days, there was no significant difference etween groups. In the day 35, only serum uric acid of melatonin group was significantly increased in comparison with egative control. Also, serum uric acid of melatonin group  increased significantly in 40 days in comparison with other roups, as melatonin plays an important role in the antioxidant defense system and uric acid is an important antioxidant inchickens. Serum glucose of positive control compared to other groups significantly increased in 40 days. Other biochemical parameters were not significant. In this study,the mean body weight of dark group was significantly decreased. The  percentage of mortality rate in negative control, dark, melatonin and positive control  treatments was zero, 4 ,5  and 10% respectively. CONCLUSIONS: These results demonstrate that  dark period and oral melatonin supplementation  candecrease HS.

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: Following the ban on the use of growth stimulant antibiotics in many countries, interest has arisen in finding  a suitable alternative for antibiotics in poultry production. OBJECTIVES: The aim of this study was to investigate the effect of supplementation of two levels of nano-copper (0 and 100 mg/kg) and two levels of mannan oligosaccharide (0 or 1 g/kg) as natural growth stimulants on digestibility of nutrients and performance in broiler chicks. METHODS: At the end of the second week of breeding, 160 Cobb-500 broiler chicks were assigned in four treatment groups. For each treatment, four replicates (10 chicks per replicate) were considered. Experiment was conducted as a 2×2 factorial model in a completely randomized design. Results: No significant differences in digestibility of nutrients and growth performance between birds that ate the supplements with control group were observed (p>0.05). CONCLUSIONS: Mannan oligosaccharides and nano-copper on growth performance and nutrient digestibility in broiler chicks had no significant effect. At the doses used, concomitant supplementation of copper and mannan oligosaccharide did not have a positive effect on traits that were studied in broilers.

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: One of the most artificial sweeteners is Aspartame which is commonly  used in a variety of foodstuffs. Objectives: This study has been carried out in order to evaluate the effects of Aspartame on histology and histometry of duodenum. Methods: Forty female Balb/C mice, 21 days of age were selected and initial weight was determined. The treatment groups received 100, 200 and 400 mg/kg of Aspartame for 6 weeks, control group received only distilled water. At the end of experiment, the mice were reweighed. Then the duodenal tissue sections were prepared and stained with H&amp;E. Besides the histological study, histometric data were collected by a light microscope equipped with Axiovision software. Results: The body weights in treatment groups (100, 200 and 400 mg/kg) were 5.57±1.18, 4.47±0.89 and 5.84±0.57 respectively, which in comparison with the control group (9.38±0.81) showed a significant difference (p<0.05). The histological study showed that the rate of destruction in the cells and mucosal structures, at the dose of 200 mg/kg compared to the dose of 100 and 400 mg/kg has been increased. In histometric aspect, abundance of duodenal villi, height of the villi and thickness of duodenal mucosa, only in the experimental group of 200 mg/kg were significantly increased compared to the control group (p<0.05). Whereas the width of villi (width of the apex, body and the base), in all of the experimental groups showed a significant decrease compared to the control group (p<0.05). The thickness of musculature of duodenum in experimental groups had no significant differences with the control group. Conclusions: Based on this study, it can be concluded that Aspartame can cause some histological and histometrical changes in duodenum.

BACKGROUND: Salmonella Enteritidis in poultry is one of the main causes of illness that can be controlled effectively by some plant compounds, antibiotics and probiotics. OBJECTIVES: This study compares the effect of rosemary, thyme, propolis, antibiotic and probiotic on the immune system and blood parameters of broilers challenged with Salmonella Enteritidis.  Methods: Four hundred and twenty 1-day- old male broiler chicks Cobb strain were divided into seven groups: including rosemary ethanol extract, ethanol extract of propolis, ethanol extract of thyme, and probiotics, virginiamycin (10%) and positive and negative controls, and were reared for 6 weeks. At the end of experiment chickens were sampled and slaughtered. RESULTS: The results showed that plant extracts with probiotics can improve the immune system, reduce serum lipids, reduce harmful bacteria such as Salmonella and E.coli and increase the beneficial bacteria such as lactic acid bacteria. CONCLUSIONS: This study showed that the herbal extracts and probiotics can be used as an alternative to antibiotics in broiler diets.

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: The Mesobuthus eupeus scorpion venoms are known to contain α-toxin peptides, many of which interfere with K+ ion channel function. These toxin peptides have important value in  the pharmacology and physiology studies of specific K+ channel of cells. OBJECTIVES: Given the  lack of information of the molecular biology of peptides in the toxin of Iranian scorpions, the aim of this study is Amplification and Analyses of cDNA sequence coding for a peptide toxin from the venomous gland of the Khuzestan province scorpion Mesobuthus eupeus. METHODS: Total RNA was extracted from the venom glands of scorpion Mesobuthus eupeus collected from  Khuzestan province of Iran and then cDNA was synthesized with the modified oligo (dT) primer. By applying the Semi-nested RT-PCR using homologous primers, the fragments of 227 bp were amplified and sequenced. RESULTS: The full-length sequence of coding region was 174 bp which  contained an open reading frame of 57 amino acids with a predicted molecular mass of 6.434 KDa and theoretical pI of 5.12. It contains a signal peptide of 19, propeptide of 4 and a mature peptide of 34 amino acids. For comparison of this peptide with the similar sequences registered in NCBI database, BLAST program was used. This protein with homology to the “Scorpion toxin-like domain” belongs to the Toxin-6 super family. CONCLUSIONS: Multiple alignment of the putative amino acid sequence of this gene exhibited the highest sequence identity with lesser Asian scorpion M. eupeus venom potassium channel α-toxin-1. This high sequence similarity indicates that this gene is a member of α-toxin from the Iranian Mesobuthus eupeus.

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.