Iranian Journal of Veterinary Medicine
Volume:5 Issue: 1, Winter 2011

Fungal agents, especially yeasts, are resident in digestive system as microflora and they can invade the mucosal tract in animals with predisposing factors. The prevalence of the resident fungal flora in the digestive tract of healthy broilers and layers during April to September 2008 was investigated. The samples were taken from the preventriculus, jejunum and cecum contents of 120 birds and cultured on Sabouraud glucose agar. Both filamentous fungus and yeasts were isolated and a predominance of the Candida species was found, followed by Trichosporon beigelii, Geotrichum candidum, Rhodotorula rubra and Saccharomyces cerevisiae species, which were found in 84.6%, 5.5%, 4.6%, 3.3% and 0.5% of cultures, respectively. Among the yeast isolates, Candida albicans (45.8%) was the most prevalent fungal agent, representing a significant proportion when compared to the other fungal isolates (P<0.05). The frequency of the yeast in the layer's digestive tract was significantly higher than that found in the broilers (P<0.05). Mycological examination revealed the highest numbers of yeasts in the cecum and lower numbers in the jejunum and preventriculus in two breeds.

The aim of this study was to determine the prevalence and type of ophthalmic diseases among horse populations in the suburbian riding clubs of Tehran. Ophthalmologic examinations were performed in 901 horses and ocular lesions were diagnosed in 40 (4.4%) animals. In the 54 eyes of these horses that had ocular defects, 103 ocular abnormalities were detected. Of those horses affected, 65% showed abnormalities in one eye and 35% had abnormalities in both eyes. Various sequelae to ocular trauma and periodic ophthalmia were the most common and recognizable causes, which comprised 25% and 15% of horses with ocular defects, respectively.

The aim of this study was to investigate the effect of bacterial inoculation on the fermentation and aerobic stability of corn silage and on the dry matter degradability and milk composition when fed to sheep or cows. Four male sheep were selected to measure dry matter degradability of uninoculated (UCS) and inoculated (ICS) corn silage. Milk composition was measured for 22 Holstein cows, separated into two treatment groups and fed with either UCS or ICS diets. Similar lactic acid concentrations but higher propionic and lower acetic acid concentrations were recorded for ICS diets compared to UCS diets (p < 0.05). Aerobic stability was 12 h and 32 h for UCS and ICS, respectively. Values of in sacco dry matter loss were higher for ICS than for UCS (p < 0.05). Lactose and solid non-fat content was higher in the milk of cows fed with ICS than UCS (p < 0.05). We conclude that the Lalsil bacterial inoculant containing propioni bacterium acidipropionici and Lactobacillus plantarum can be used as an additive due to its positive effect on fermentation, aerobic stability and dry matter degradability of corn silage. The slight positive effect of inoculcation on the nutritional value of silage appears to be limited to milk production improvement in dairy cows.

Infectious bronchitis (IB) is an economically important disease of chickens. Due to the emergence of new variants of infectious bronchitis virus (IBV), the control of IB has become a serious problem for the poultry industry worldwide. In the present study, the nucleocapsid gene (N) and 3' untranslated region (UTR) of two IBVs isolated from Iranian poultry farms were sequenced and compared with other IBV strains. Based on nucleotide identity, the N gene and 3' UTR sequences of Iranian IBVs showed 90% similarity to the commonly used IBV vaccine strains, H52 and H120. However, based on phylogenetic analyses, Iranian IBVs were found to cluster separately from the IBV vaccine strains used in Iran as well as other IBVs isolated in China, Australia and the United States. It was concluded that IBVs circulating in Iran are genetically distinct from IBV vaccine strains that have been used in Iran for many years. Therefore, it is important to develop a new vaccine based on these newly identified strains for controlling IB in Iranian poultry farms.

The major histocompatibility complex (MHC) plays a central role in the control of disease resistance and immune response. Extensive genetic diversity in MHC genes provides a valuable source for genetic improvement, via selection, in many domestic animals. Exon 2 of the class II MHC, termed Ovar-DRB1 in domestic sheep (Ovis aries), has been suggested as important disease resistance and immune response gene. We characterized Ovar-DRB1 in DNA samples from 138 individuals of a population of the Iranian Sangsari sheep breed using PCR-RFLP. Eight DRB1 alleles were identified among Iranian Sangsari sheep, including one previously unrecognized allele. Eight homozygous genotypes were observed: a, b, c, d, f, g, h and N. Genotype bb was the most common pattern (46 of 138). Heterozygous genotypes (ag, cb, cd, bf, and bN) were also observed. The observed homozygosity and heterozygosity values were 0.6377 and 0.3623, respectively, vs expected values of 0.220 and 0.779. Iranian Sangsari population deviate significantly from the theoretical proportions (FIS = 0.5283; p = 0.0005). In conclusion, PCR-RFLP analysis allows rapid identification of Ovar-DRB1 types and discrimination of homozygous and heterozygous genotypes. This study indicates that the exon 2 region of the Ovar-DRB1 gene is highly polymorphic in the Iranian Sangsari sheep breed.