Standardization of the outbred BALB/c mice as a suitable animal model for <Emphasis Type="BoldItalic">Besnoitia caprae</Emphasis> studies

The Apicomplexan parasite Besnoitia caprae infects wild and domestic goats. Knowledge on Besnoitia caprae specially an optimized animal model is sparse. Experimental infections with tachyzoites of BC-Pars obtained from BALB/c mice were conducted in outbred mice to determine the infectivity and LD50 of Besnoitia caprae. Six groups of five mice were intraperitoneally infected with 12.5 × 10³, 25 × 10³, 5 × 10⁴, 1 × 10⁵ and 2 × 10⁵ tachyzoites and a control inoculum of DMEM, respectively. Although morbidity and mortality were observed in all groups, two mice in the 12.5 × 10³ group showed alopecia and skin lesions on 60 days post-infection (DPI). Histopathological and molecular examination of skins confirmed B. caprae infection. The LD₅₀ was calculated as 25 × 10^3.2 tachyzoites per mouse. The results indicate that outbred BALB/c mice can be used as a suitable model of besnoitiosis and to screen candidate treatments and to test the efficacy of vaccines for besnoitiosis.     

Antibiotics,Penicillin and Sreptomycin improve semen quality indices of endangered Caspian brown trout,Salmo trutta caspius (Kessler, 1870) during in vitro short‐term storage

In this study, we examined the effects of 500 IU mL^?1 penicillin + 500 μg mL^?1 streptomycin sulphate on semen quality indices of endangered caspian brown during 12 days short‐term storage at 4°C. Twenty‐four millilitre semen samples with good quality were considered for the experiment. The semen samples were then stored in the presence and absence of 500 IU mL^?1 penicillin + 500 μg mL^?1 streptomycin sulphate. The semen quality parameters including percentage and duration of sperm motility were measured 0, 3, 6, 9 and 12 days after storage. In the antibiotic receiving group, the values of percentage and duration of sperm motility reduced 3 and 6 days after storage respectively and reduced to lowest levels at day 12. In the antibiotic‐free group, the duration and percentage of sperm motility decreased significantly after 3 days of storage and reached to lowest values at day 12. Also, percentage and duration of sperm motility in each storage time were significantly higher in the antibiotic receiving group than in the antibiotic‐free group. The overall values of percentage and duration of sperm motility for all storage periods were higher in the antibiotic receiving group than in the antibiotic‐free group. In conclusion, our results demonstrated that 500 IU mL^?1 penicillin + 500 μg mL^?1 streptomycin sulphate improves the viability of caspian brown trout during short‐term storage.     

Comparing the efficacy of dietary α-tocopherol with that of dl-α-tocopheryl acetate, both either alone or in combination with ascorbic acid, on growth and stress resistance of angelfish, Pterophylum scalare, juveniles

This study aimed to compare the efficacy of dietary α-tocopherol with that of dl-α-tocopheryl acetate, both either alone or in combination with vitamin C (ascorbic acid), on the growth performance, survival, and stress resistance of angelfish, Pterophylum scalare, juveniles. Juveniles were fed ad libitum for four weeks with Artemia enriched with no vitamins (control), vitamin C (T_c), α-tocopherol (T_α), dl-α-tocopheryl acetate (T _dl ), α-tocopherol and vitamin C (T_α+C), and dl-α-tocopheryl acetate and vitamin C (T _dl+C). After four weeks, an osmotic stress test was performed using seawater (25 g/L) to evaluate juvenile’s resistance to stress. Whole-body glucose and cortisol were used as stress indicators. At the end of the feeding trial, growth performance and survival of the juveniles fed vitamin-enriched Artemia were significantly (P < 0.05) higher than for the control fish. Best performance was recorded for the T_α+C group. Survival, however, was not significantly (P > 0.05) different between the vitamin-fed groups. Osmotic stress significantly elevated the stress indicators, whole-body cortisol and glucose levels (P < 0.05), highest and lowest values being observed in control and T_α+C groups, respectively. Survival after osmotic stress of juveniles fed the T_α+c diet was significantly higher (by 46.2%, P < 0.001) than for controls. Results suggested that α-tocopherol has greater efficacy than dl-α-tocopheryl acetate and enriching Artemia with α-tocopherol and vitamin C together improves growth performance, survival, and stress resistance of angelfish juveniles.     

Growth performance,immune response and disease resistance of rainbow trout (Oncorhynchus mykiss) fed Thymus vulgaris essential oils

Efficacy of Thymus vulgaris essential oils was assessed on growth, immune response and disease resistance of rainbow trout (Oncorhynchus mykiss). Fish weighing 10 g were fed with dietary supplemented of the oils at 0.5, 1.0 and 2.0 ml/kg feed for 2 months. Fish fed with the oils at 0.5 ml/kg feed demonstrated a better weight gain and specific growth rate, compared to other treatments (p < .05). Fish fed with 1.0 ml the oils showed the highest up‐regulation of complement component 3 (C3) and (cluster of differentiation 4) (CD4) genes expression (p < .05), while lysozyme gene expression level significantly increased in fish fed with 2.0 ml of the oils. In addition, at the end of the experiment, the expression of C3 and CD4 genes were significantly up‐regulated in fish fed with 1.0 and 2.0 ml of the oils, while IL‐1ß and lysozyme genes expression levels were significantly decreased in fish fed 2.0 ml oils, towards the end of the trial (p < .05). There was a fluctuation in the levels of Alanine aminotransferase, Aspartate aminotransferase and Alkaline phosphatase in all treatments during the experiment. When treated fish were challenged with Aeromonas hydrophila, the highest survival rate was observed in 0.5 ml/kg treatment, followed by 2 and 1 mg/kg treatments. Overall, these findings demonstrated that dietary administration of T. vulgaris oils especially at 0.5 mg/kg feed can be considered as a potential component for enhancing of the growth, immune responses and disease resistance of trout against motile Aeromonas septicemia caused by A. hydrophila.     

Exploring the potential for top-dressing bread wheat with ammonium chloride to minimize grain yield losses under drought

The frequency and severity of drought is predicted to rise in many parts of the world. Considering that drought is the main constraint on rain-fed wheat crop production, both agronomic and genetic measures have been taken to minimize yield losses under drought. Beyond its role as a micronutrient, chloride also acts as an osmoticum, implicated in the regulation of stomatal aperture. This study explores the potential for chloride fertilization of Australian bread wheat (Triticum aestivum L.) to minimize grain yield losses caused by drought stress. For this, two drought-tolerant commercial genotypes (Mace and Gladius) and a well-studied drought-tolerant genotype used in wheat breeding (RAC875) were treated with ammonium chloride, potassium chloride, or ammonium bicarbonate, the latter two treatments served as controls for chloride and ammonium, respectively. Plants were grown under either a watered or water-restricted (drought) regime. The genotype RAC875 was found to accumulate leaf chloride at a significantly higher level than the other genotypes under optimal growth conditions. Under drought conditions, top-dressing RAC875 plants with ammonium chloride resulted in up to a 2.5-fold increase in grain number and this effect was not seen when plants were top-dressed with either of the control fertilizers. The ammonium chloride treatment also minimized losses of grain yield in RAC875 plants grown under drought. Treatment effects were accompanied by an increase in stomatal conductance. These results collectively suggest that the compound fertilizer ammonium chloride can improve drought tolerance of wheat.     

Effect of ethanolic extract of Zingiber officinale on growth performance and mucosal immune responses in rainbow trout (Oncorhynchus mykiss)

This study was conducted to examine the effect of ethanolic ginger (Zingiber officinale) extract on growth performance and some skin mucus immune parameters in rainbow trout (Oncorhynchus mykiss). A total of 600 rainbow trout fingerling (10.07 ± 0.21 g) were randomly assigned to four groups in triplicate and fed for 45 days with 1, 2.5 and 5 g kg^?1 of ginger extract and with unsupplemented basal diet as the control. The total protein content and lysozyme, alkaline phosphatase and protease activities of skin mucus were investigated following 15, 30 and 45 days of feeding. Results showed that administration of 2.5 and 5 g kg^?1 of ethanolic ginger extract for 45 days improved weight gain, feed utilization efficiency and feed conversion ratio of O. mykiss (P < 0.05). Significantly higher (P < 0.05) skin mucus lysozyme, alkaline phosphatase and protease activity and protein level were observed in the 2.5 and 5 g kg^?1 ginger extract groups on the 30th and 45th day compared to the controls. The findings suggest that ethanolic extract of ginger enhances growth performance and skin mucus immune parameters of rainbow trout.     

Evaluation of different media and methods of cultivation on the production and viability of entomopathogenic fungi, Verticillium lecanii (Zimm.) Viegas

For mass production of V. lecanii, three types of cultivation methods including liquid, solid and diphasic production systems were investigated. In the liquid state of production, six media were tested in stationary culture conditions. Among the six media tested, Molasses Yeast Broth (MYB) supported maximum sporulation (8.33 x 10(8) spores mL(-1)) and biomass production (746 mg/100 mL). In the MYB, 4% molasses concentration was found to produce highest spore count (8.56 x 10(8) spores mL(-1)) and biomass (776 mg/100 mL) followed by 5 and 6% molasses. Among the six solid substrates tested, rice grains supported highest spore production (1.14 g/100 g). In diphasic state of production, combination of MYB and rice grains produced the greatest amount of spores, (1.70 g/100 g). Results of this study indicated that diphasic method using MYB as liquid medium and rice as solid substrate are the best method and media for mass production of V1-7 isolate of V. lecanii.     

Molecular genetic diversity and population structure of Iranian honey bee (Apis mellifera meda) populations: implications for breeding and conservation

Journal of Plant Diseases and Protection - The honey bee (Apis mellifera), as one of the most important pollinating insects, plays a critical role in biodiversity conservation and global food...     

Prevalence and antimicrobial resistance of Arcobacter species isolated from poultry meat in Iran

1. The objective of this study was to determine the prevalence and antimicrobial resistance of Arcobacter spp. isolated from different species of retail poultry meat in Iran.

2. From August 2012 to April 2013, a total of 540 raw poultry meat samples from chicken (n = 100), turkey (n = 100), quail (n = 100), partridge (n = 80), duck (n = 50), ostrich (n = 60) and geese (n = 50) were purchased from randomly selected retail outlets in Shahrekord, Isfahan, Sari and Rasht, Iran.

3. Using culture techniques, 71 of 540 poultry meat samples (13.1%) were positive for Arcobacter spp. The highest prevalence of Arcobacter spp. was found in chicken meat (28.0%), followed by quail (12.0%), duck (11.4%), turkey (11.0%), geese (8.0%), partridge (7.5%) and ostrich (3.3%) meat. The number of A. butzleri isolated from poultry meat samples (90.1%) was significantly higher than A. cryaerophilus (7.1%) and A. skirrowii (2.8%). Significantly more poultry meat samples were found to contain Arcobacter spp. by the PCR assay than by the culture method.

4. Susceptibilities of Arcobacter isolates were determined for 14 antimicrobial drugs using the disk diffusion method. All of the 71 Arcobacter isolates tested were resistant to one or more antimicrobial agents. Resistance to cephalothin and vancomycin (95.8%) was the most common finding, followed by resistance to methicillin, azithromycin and ampicillin. All Arcobacter isolates were susceptible to gentamicin, streptomycin, tetracyclin and kanamycin.

5. The results of this study indicated the importance of poultry meat, especially chicken meat, as potential sources of Arcobacter spp. infection in people. Furthermore, the strains indicated resistance to a broad spectrum of antibiotics.     

Effect of protein source and protease addition on performance,blood metabolites and nutrient digestibility of turkeys fed on low-protein diets from 28 to 55 d post hatch

1. The objective of this study was to investigate the effect of a monocomponent protease and dietary inclusion of canola meal (CM) and poultry by-product meal (PBM) on growth performance, carcass characteristics and blood metabolites of turkeys fed on low crude protein (CP) diets from 28 to 55 d post hatch.

2. Experimental treatments included control, maize–soybean meal diet including 258.3 g/kg CP; negative control 1 (NC1), maize–soybean meal diet with reduced CP (232.4 g/kg); NC2, control diet (CP, 258.3 g/kg) including CM (80 g/kg) and PBM (80 g/kg); NC3, maize–soybean meal diet with reduced CP (232.4 g/kg) including CM (80 g/kg) and PBM (80 g/kg). Also, the NC1 + P and NC3 + P diets were created by addition of protease enzyme (30 000 units/kg of diet) to the NC1 and NC3 diets, respectively.

3. The NC3 group had lower body weight gain (BWG) compared to those fed on the control diet, and no improvement with enzyme addition (NC3 + P) was achieved. The protease addition to the NC1 diet (NC1 + P) improved BWG to the level of the control diet. The NC1 group had higher feed conversion ratio (FCR) compared to the control and NC3 + P, but protease addition to the NC1 diet improved FCR.

4. Protease addition to the low CP diets resulted in higher nitrogen (N) retention than in the control and NC2 groups. Also, the NC1 + P and NC3 + P diets increased apparent ileal digestibility (AID) of CP compared to the control group.

5. It was concluded that addition of CM (up to 80 g/kg) and PBM (up to 80 g/kg) to turkey diets had no negative effect on growth performance from 28 to 55 d of age. The NC1 + P group achieved the BWG of the control group which was partially due to increases in N retention and AID of CP, but the NC3 + P group failed to recover the growth losses. This difference implies that the efficacy of the protease may depend upon the protein source in the ration.