Veterinary Research & Biological Products
Year:2011 | Volume:24 | Issue:2 (91)|Papers Count:8

Bovine leukemia virus (BLV) is a retrovirus causing a chronic leukemia/lymphoma in cattle in many countries around the world. Screening for antibodies by Elisa has been the primary means of detecting the presence of this virus. It is not yet known if this assay will detect antibodies in all cattle during a concomitant bovine leukemia virus infection. The polymerase chain reaction (PCR) of the target proviral DNA in peripheral blood mononuclear cells (PBML). In order to find a highly sensitive and efficient method for the diagnosis of BLV infection in different matrices as well as blood samples, we have designed a Nested-PCR method to detect BLV-gag proviral DNA in naturally infected cattle together with paraffin embedded blocks and degraded DNAs. Samples of natural infected cows (n=281), paraffin embedded (n=3) and degraded DNA (n=10) were examined. When using ELISA as a reference test, sensitivity and specificity for nested PCR were 0.85 and 0.84, respectively. Interpretation of kappa scores for two methods was substantial (0.693). Predictive value of a positive test was 0.82, and predictive value of a negative test was 0.86. The percentage of cows correctly classified by nested PCR assay was %85. This strategy have shown to allow detection at different experiments and had higher sensitivity in comparison with normal PCR. This latter technique is useful for mass screening and could be useful to detect proviral DNA in paraffin embedded or old samples.

In this research the effect of two different methods of carcass chilling (Immersion and Evaporative) in the poultry industrial slaughter line on microbial load and carcass weight changes was studied. For sampling, after evisceration, each carcass weighted and rinsed with 250 ml of sterile water in a plastic bag. 25 ml of rinses water was taken and into sterile scaled container sent to laboratory. After identified of carcasses with tag, them back to slaughter line and sent to chilling tank or evaporative system. Considering that the water in evaporative system, after flow on carcass is out than system and don't contact to carcass again, thus sampling was done in one step only. At the end of chilling, carcasses were weighted and sampled as same as before of chilling. Results show that carcass weight mean decrease approximately %5.9 in evaporative method and increase 5.5, 5.1 and 4.1 percent in the first, middle and end of slaughter, in immersion method respectively and this differences were not significant between before and after of chilling (p>0.05). Total count in evaporative method decreased 62.4 percent that had significant difference with immersion method. Also total count in first time of immersion method had significant difference with end of the slaughter time (p<0.05). Primary Coliforms (before of chilling) shown significant different in each of two methods although coliforms change ratio between whole treatment was not significant (p>0.05). The results of this study show that microbial load increase in slaughter line with passing time and water absorption of carcasses in immersion method is more than evaporative method. Also carcass discoloration was seen in evaporative method.

This experiment was conducted in order to determine the effects of different dietary growth promoters on growth performance and nutrient digestibility in male broiler chickens. A total of 360 male broiler chicks (day-old Ross 308 strain) were distributed into a Completely Randomized Design (CRD) having 6 dietary treatments with four replicates and 15 birds in each replicate. Experimental treatments were: 1) Basal diet, 2) Basal diet+15 ppm Virginamycin antibiotic, 3) Basal diet+0.1 g/kg Protexin probiotic) Aspergillus oryzae, Lactobacillus acidophilus, L. rhamnosus, L. plantarum, L. bulgaricus, Bifidobacterium bifidum, Enterococcus faecium, Streptococcus thermophilus and andida pintolopesii), 4) Basal diet+0.1 g/kg Immnowall prebiotic (mannanoligosaccharide), 5) Basal diet+0.45 g/kg Digestarom medicinal plant extract, and 6) Basal diet+0.4 g/kg Formycin organic acid. Ileal digestibility of nutrients was determined using titanium oxide marker at 21 and 42 days of age. Results of this study indicated that chicks fed diets supplemented with growth promoters had greater average daily gain and lower feed conversion ratio compared to those fed the control (basal) diet (P<0.05). Furthermore, using growth promoters in the diets led to more energy availability and greater ileal protein digestibility (P<0.05). However, ileal ether extract digestibility was not significantly influenced by the experimental treatments (P>0.05). There were no significant differences between relative weights of thigh, breast, and liver due to dietary treatments (p>0.05). Relative weights of spleen and bursa of fibricius were significantly higher in birds fed diets supplemented with growth promoters than in those fed the control diet (P<0.05). Abdominal fat was found to be significantly higher in antibiotic-supplemented group than in the control group (P<0.05).

This study was carried out to evaluate the impacts of organic (Sel-Plexâ selenium yeast) and inorganic (sodium selenite) selenium and vitamin E (d1-a-tocopheryl acetate) on performance and carcass characteristics in broiler chickens. The effect of two types of house temperature and six treatments of feed additives were investigated in a 2×6 factorial experiment at 56 days period with 960 commercial broiler chicks (Arbor acres) using a completely randomized design with four replications and 20 day-old chicks in each pen. Birds reared in heat stress condition, exposed daily to 37oC for 8 hours throughout the experiment. Experimental feed treatments were: 1) control diet with no additives (Ctl), 2) control+0.3 ppm Sel-Plexâ (SY), 3) control+0.3 ppm SY+50 mg/Kg Vitamin E (SY+E), 4) control+0.3 ppm sodium selenite (SS), 5) control+0.3 ppm SS+50 mg/Kg Vitamin E (SS+E), 6) control+50 mg/Kg Vitamin E (E). The birds reared in heat stress condition had lower weight gain at 1-21, 21-42 and 1-56 days (P>0.05), significantly lower feed consumption at 21-42 days and the whole experiment period (1-56 days), and greater means of feed conversion ratio at 1-21 days than birds reared in normal temperature (P>0.05). Weight gain was not affected by the additives treatments at the first 21 days, but birds fed diets supplemented with SY, SS, SS+E and E had significantly greater means for weight gain at the period of 21-42 and whole period of the experiment (P<0.05). Feed consumption significantly affected by feed additives at 42-56 days (P>0.05). Birds fed diets with SY and SS showed significantly lower feed conversion ratio throughout the experiment except at the first 21 days (P<0.05). Interaction between the house temperature and feed additives had significant effect on weight gain throughout the experiment except at the 1-42 and 42-56 days of age, feed consumption at 21-42 days of age, and feed conversion ratio at whole experiment period (P<0.05). Results of this study showed that house temperature and feed additives treatments and interaction between them had no significant effect on carcass yield percentage, liver percentage, abdominal fat percentage (P>0.05). Mortality was not affected by the house temperature and feed additives and interaction between them (P>0.05). According to results of this experiment the birds reared in heat stress condition had lowest production efficiency ratio, but the birds fed diets supplemented with SY and SS had significantly greater means of production efficiency ratio (P<0.05).

This experiment was conducted to investigate the effects of using protexin, propionic acid growth promoters, and a blend of them on broilers performance. In a completely randomized design, three hundreds and twenty unsexed 1-d-old chicks were divided into four groups. Dietary treatments were consisted of 1) control diet without any supplement, 2) the control diet+0.01% protexin, 3) the control diet+0.2% propionic acid, 4) the control diet+0.01% protexin+0.02% propionic acid. Body weight gain and feed intake were measured weekly. In the first week, the use of protexin and propionic acid increased body weight. In the fourth week, the group fed a diet supplemented with propionic acid had lower feed intake and feed conversion ratio than the others groups. In the fifth week, the broilers fed with protexin and a blend of protexin and propionic acid had better feed conversion ratio compared to the others experimental units. The birds fed with all of the feed additives, especially propionic acid, had betted energy intake and energy efficiency ratio than control diet. Based on the results of this experiment, these feed additives, especially propionic acid, can be suggested as suitable growth promoters in broiler chickens nutrition.

An experiment was conducted under completely randomized design to investigate effect of various levels of terbutalin, a bete-adrenergic agonist, by procuring 120, 35-d age male cobb broiler chicks from d 29-49. The birds were randomely distributed into 3 treatments and 4 replicates with10 birds each. The birds were fed experimental diets with different levels of terbutaline at levels 0.0 (control), 7.5 and 15 ppm/kg. Feed intake and liveweight were weekly measured. At the end of the experimental periods, 20 chicks from each group were randomly selected and blood samples were collected, 8 birds also were selected for carcass analysis. Blood metabolites were assayed via spectrophotometric methods and hormones via radioimmunoassay. Results showed that terbutaline at lower level of inclusion had significantly affect on weight gain, feed intake and feed conversion ratio vs. control group (p<0.05). Low level of terbutaline caused significant increases in carcass weight, carcass yeild, breast weight and thigh weight as 10.3, 5.2, 3.4, 4.8% and decreased in abdominal fat as 22.8% as compared to control group, respectively (p<0.05). Terbutaline inclusions significantly increased protein percentage of breast and thigh and decreased fat percentage of breast vs. control (p<0.05). Both levels of Terbutaline inclusion had significantly increased in blood glucose, triglycerides, cholesterol and thyroxine levels, but decreased in blood insulin, urea nitrogen and uric acid levels (p<0.05). It has no significant effects on blood alanine, glutamine, creatine kinase and aspartate amino-transferase enzymes levels. In general, the results showed that terbutaline inclusions especially in 7.5 ppm/kg in broiler diets can improve performance and carcass traits.

Campylobacter is one of the main potentials for causing diarrhea and gastroenteritis in human saityand. One of the main sources of these bacteria is meat. Method and material: 100 samples of broiler's meat which were slaughtered in slaughter halls all over Rafsanjan city were collected during the first 5 months of the year 1389. This study was conducted to determine the prevalence and antimicrobial resistance of Campylobacter spp, Isolated from poultry meat slaughtered in Rafsanjan slaughter houses. During this study, 31 samples (31%) were discovered to be infected and after passing chemical analysis 19 samples (61.29%) were recognized to be Campylobacter jejuni and 12 samples (38.71%) were declared Campylobacter coli. Antibacterial sensitity tests revealed that these bacteria are most susceptible to Erythromycin and Ciprofloxacin but resistant to Gentamycin and Co-trimoxazole. This study showed a high contamination of broiler's meat to the campylobacter which is consumed as a food source. And as favas concerned about the zoonotic nature of this bacteria, it is expected to have a better attention over this matter.

A study conducted to Isolation and identification of Honey bee diseases fungal agents in Iran West Azarbaijan province apiaries. We collected 2000 samples (Adult honeybee, brood, honey and pollen) of 200 apiaries in three seasons (spring, summer and autumn). Samples prepared and cultivated in SDA medium. Finally, Ascosphaera apis, causative agent of Chalk brood disease, didn't isolate of any apiaries, but 4.29 of samples was contaminated with Aspergillus flavus and 2.04 present of them was contaminated with Aspergillus fumigatus, causative agents of Stone-brood disease.