Iranian Journal of Veterinary Research
Volume:16 Issue: 3, Summer 2015

The aim of this study was to investigate the potential association between growth hormone GH/AluI and growth hormone receptor GHR/AluI polymorphisms with milk yield and reproductive performances in Holstein dairy cows in Iran. Blood samples of 150 Holstein cows were collected and their genomic DNA was extracted using Gene-Fanavaran DNA extracting kit. Fragments of the 428 bp of exon 5 growth hormone (GH) gene and the 342 bp of exon 10 growth hormone receptor (GHR) gene were amplified using the polymerase chain reaction (PCR) method. PCR products were digested by the AluI restriction enzyme and electrophoresedon 3% agarose gel. Continuous and categorical data were analyzed using linear mixed models through Proc MIXED and logistic regression models through Proc GENMOD of SAS software, respectively. The results showed no relationship between the examined traits and GH/AluI or GHR/AluI genes. A significant relationship was found between GH/AluI polymorphism and dystocia, but the presence of the GH-L allele reduced the incidence of dystocia. The results suggest that the GH-LL genotype reduces dystociaprobably by affecting the release of growth hormone; nevertheless, further studies will be needed to examine the relationship between dystocia and GH genotypes.

The ability of whey protein concentrate (WPC) (1% w/v) and/or honey (2% and 4% w⁄v) to improve lactic acid bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) growth and viability in yoghurt during a 21 day period of storage was investigated. Another focus of this study was to examine fermentation kinetics and post-acidification rates through pH and lactic acid content measurements over the 21 day period. The addition of WPC and acacia honey accelerated fermentation and improved lactic acid bacteria (LAB) growth over the 21 days، but honey proportion did not significantly affect the viability of LAB. Moreover، adding honey and WPC did not support the overproduction of lactic acid، which positively influenced yoghurt stability during the 21 day storage period.

An in vivo experiment was conducted to study the effects of probiotic Bacillus coagulans spores، with and without prebiotic، inulin، on gastrointestinal (GI) microbiota of healthy rats and its potentiality to survive in the GI tract. Forty-eight male Wistar rats were randomly divided into four groups (n=12) and fed as follows: standard diet (control)، standard diet supplied with 5% w/w long chain inulin (prebiotic)، standard diet with 109/day spores of B. coagulans by orogastric gavage (probiotic)، and standard diet with 5% w/w long chain inulin and 109 spores/day of B. coagulans by orogastric gavage (synbiotic). Rats were fed the diets for 30 days. At day 10، 20 and 30 of experiment، 24 h post administration، four rats from each group were randomly selected and after faecal collection were sacrificed. Small intestine، cecum، and colon were excised from each rat and used for microbial analysis. Administration of synbiotic and probiotic diets led to a significant (P<0. 05) increment in lactic acid bacteria (LAB)، total aerobic and total anaerobic population compared the prebiotic and control diets. A significant decrease in Enterobacteriaceae counts of varioussegments of GI tract (except small intestine) in synbiotic، probiotic and prebiotic fed groups were also seen. The obvious decline in spores count through passing GI tract and high surviving spore counts in faecal samples showed that spores are not a normal resident of GI microbiota and affect intestinal microbiota by temporary proliferation. In conclusion، the present study clearly showed probiotic B. coagulans was efficient in beneficially modulating GI microbiota and considering transitional characteristics of B. coagulans، daily consumption of probiotic products is necessary for any long-term effect.

This study aimed to estimate microsatellite based genetic diversity in two lines (the selected RIRS and control line RIRC) of Rhode Island Red (RIR) chicken. Genomic DNA of 24 randomly selected birds maintained at Central Avian Research Institute (India) and 24 microsatellite markers were used. Microsatellite alleles were determined on 6% urea-PAGE, recorded using GelDoc system and the samples were genotyped. Nei’s heterozygosity and Botstein’s polymorphic information content (PIC) at eachmicrosatellite locus were estimated. Wright’s fixation indices and gene flow were estimated using POPGENE software. All the microsatellite loci were polymorphic and the estimated PIC ranged from 0.3648 (MCW0059) to 0.7819 (ADL0267) in RIRS and from 0.2392 (MCW0059) to 0.8620 (ADL0136) in RIRC. Most of the loci were highly informative (PIC>0.50) in the both lines, except for five loci in RIRS and six loci in RIRC line. Nei’s heterozygosity per locus ranged from 0.4800 (MCW0059) to 0.8056 (ADL0267) in RIRS and from 0.2778 (MCW0059) to 0.875 (ADL0136) in RIRC. Out of 24 loci, 15 (62.5%) in RIRS and 14 loci (58.33%) in RIRC revealed moderate to high negative FIS index indicating heterozygote excess for these loci in corresponding lines, but the rest revealed positive FIS indicating heterozygosity deficiency. A mean FIS across the both lines indicated overall 10.77% heterozygosity deficit and a mean FIT indicated 17.19% inbreeding co-efficient favoring homozygosity over the two lines. The mean FST indicated that 10.18% of the microsatellite variation between the two lines was due to their genetic difference.

Zinc (Zn) is an essential trace element in all living organisms، and the first eukaryotic Zn uptake transporter was discovered in the yeast، Saccharomyces cerevisiae. Zinc-enriched yeast is a currently available Zn supplement. The purpose of the investigation was to compare and evaluate the effect of Zn enriched yeast in rainbow trout. The fish (mean body weight 10 ± 0. 5 g) were fed a commercial diet supplemented with 0 (control)، 1 × 106، 1 × 107 and 1 × 108 CFU/g of Zn-enriched yeast for 60-days. Results showed that significant increase in serum lysozyme activity، complement activity and total immunoglobulin were seen in all treatment groups during feeding trial when compared to the control group. On the basis of our findings، Zn-enriched improved rainbow trout growth، some immune parameters and disease resistance.

The sip gene encoding for a conserved highly immunogenic surface protein of Streptococcus agalactiae was amplified using polymerase chain reaction (PCR) and subcloned into prokaryotic expression vector pET32a (+) and expressed as a recombinant protein in E. coli BL21 (DE3). An indirect enzyme linked immunosorbent assay (ELISA) was developed using the purified Sip protein as a coating antigen، which could identify S. agalactiae specific antibody in sera. The coating antigen at a concentration of 3. 125 μg/ml، serum diluted to 1:160، and HRP-conjugated secondary antibody concentration at 1:4000 was found to be most effectivein exhibiting positive result. The ELISA was found to be highly specific for S. agalactiae that may be used for the detection of the pathogen in mastitis cases، for epidemiological studies and for surveillance.

Methyl tertiary-butyl ether (MTBE) is used to reduce carbon monoxide and ozone in urban air and to boost fuel octane. There is a lack of knowledge in the literature about the histomorphometric changes of the testis following exposure to MTBE. Therefore، this experimental study was performed to determine the effect of oral exposure to MTBE on histologic and histomorphometric changes of testis in adult rat. A total of 25 adult male Sprague-Dawley rats were randomly divided into five equal experimental groups: control، almond oil and three treatment groups which received 400، 800 and 1600 mg/kg/day MTBE in almond oil by gavages for 30 consecutive days. Histomorphometric analysis showed no significant difference in absolute and relative testis weight، connective tissue thickness، germinal epithelium height، tunica albuginea thickness and Sertoli cell numbers between experimental groups (P>0. 05). However، trend analysis showed that the seminiferous tubule diameter increased and interstitial cell numbers as well as spermatocyte and spermatid cell numbers decreased significantly in MTBE treated groups (P<0. 05). It may be concluded that MTBEcould exert adverse effects on spermatogenic cells in adult rat. Whether the observed changes in the present study are due to the direct effect of MTBE via passing blood-testis barrier or its indirect effect through another mechanism should be elucidated in future studies.

This study aims at molecular identification of Salmonella Infantis isolated from backyard chickens and the detection of their antibiotic resistance genes. A total of 46 Salmonella-suspected samples isolated from backyard chickens of northern Iran were collected. Serotyping was done by the traditional method and then confirmed by PCR. Antimicrobial susceptibility of the isolates against 13 antimicrobial agents was determined by the standard disk diffusion method. There were 44 samples identified as Salmonella. Serotyping results showed that all 44 isolates belonged to serogroup C1 and serovar Infantis. The most resistance observed was to tetracycline and doxycycline (100%)، chloramphenicol (79%) and florfenicol (72%). The floR، catI، tetA and tetG genes were used for the detection of florfenicol chloramphenicol and tetracycline resistance. In order to identify the phenotypic resistance in strains which showed resistance genes by PCR، colony PCR and culture on plates each containing antibiotic was performed simultaneously. All the Salmonella Infantis resistant to florfenicol and chloramphenicol harbored floR and catI. None of the Salmonella resistant to tetracycline carried tetA or tetG. The result of colony PCR and culture in antibiotic medium confirmed theresults of PCR and indicated phenotypic resistance in these samples.

The aim of this study was to determine the effect of low levels of glutathione on post-thawed buck sperm quality. In this experiment، different concentrations of glutathione [0 (LG-0)، 0. 5 (LG-0. 5)، 1 (LG-1)، 1. 5 (LG-1. 5)، and 2 (LG-2) mM] were added in a soybean lecithin-based extender. A total of 16 ejaculates from four bucks were collected and pooled. Each pooled sample was divided into five equal parts and each part was diluted by one of the above mentioned groups. After freeze-thawing process، motility and velocity، plasma membrane integrity and functionality، and apoptosis features of spermatozoa were evaluated. The results of this experiment showed that total motility (50. 75 ± 2. 33)، plasma membrane integrity (55. 75 ± 3. 01) and functionality (46. 75 ± 2. 79) were higher in LG-1 extender compared to other extenders (P<0. 05). The percentage of live spermatozoa (53. 23 ± 3. 26) was higher in LG-1 extender compared to other extenders، with the exception of LG-1. 5 extender (P<0. 05). Also، the percentage of late apoptotic spermatozoa (21. 33 ± 1. 63) was lower in LG-1 extender compared to other extenders (P<0. 05). In conclusion، our results showed that GL-1 extender resulted in higher post-thawed buck sperm quality compared to other extenders.

There are many techniques to knock out directed genes in bacteria، some of which have been described in Salmonella species. In this study، a combination of SOEing PCR method and the λ Red disruption system were used to disrupt phoP gene in wild type and standard strains of Salmonella typhimurium. Three standards PCR and one fusion PCR reactions were performed to construct a linear DNA including upstream and downstream of phoP gene and Kanamycin cassette. As a template plasmid، we used pKD4 whichcarries kanamycin gene flanked by FRT (FLP recognition target) sites. The resulting construct was electroporated into prepared competent cells of S. typhimurium. The transformants colonies related to the standard strain appeared on the LB-Km-agar plates after incubation، but there was no colony on LB-Km-agar plates corresponding to the wild type strain. The failure in transformation of the wild type strain may be because of inflexibility of the λ Red disruption system in this strain or its unique restriction-modificationsystem. However، by this construct we are able to generate phoP mutant in many of the Salmonella species due to high homology of the phoP gene which exists in different species.

A one-day-old male Holstein calf was presented with a palpable subcutaneous mass، extending from the parotid to the orbital region، involving the entire right side of the face and a large flabby mass without any evidence of inflammation or edema on the tongue. Macroscopically، the cut surface of the lingual mass appeared slightly lobulated، pink، with a mucoid appearance and gelatinous consistency. Histopathological examination confirmed the infiltrative subcutaneous lipoma and lingual myxoma evidenced by low cellularity and abundant basophilic، mucinous stroma. In this report، clinical and detailed histhopathological findings of congenital infiltrative myxoma and its coincidence with infiltrative facial lipoma is reported in a newborn calf.

Endocarditis is rarely reported in sheep and information presented for ovine endocarditis is based mostly on comparative findings in the cattle. Infective vegetative endocarditis of the right heart was diagnosed in a 3-year-old fat-tailed ram. Clinical findings included tachycardia، marked brisket edema، jugular veins distention and pulsation and pale mucous membranes. Hematologic abnormality included neutrophilic leukocytosis. Necropsy confirmed severe right atrioventricular and pulmonary valves vegetative endocarditis with evidence of right heart failure. Erysipelothrix rhusiopathiae was isolated from those vegetative lisions.