Parasitology
Maryam Ansari-Lari; Abbas Rowshan-Ghasrodashti; Hadi Jesmani; Maliheh Masoudian; Mehrdad Badkoobeh
Volume 8, Issue 2 , June 2017, , Pages 109-114
Abstract
There is no prospective study from Iran to estimate the direct risk of Neospora caninum for pregnancy loss or reproductive factors. In addition, there is no report in the literature concerning the association of N. caninum with dystocia and sex of calves. Therefore, this study was conducted on a group ...
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There is no prospective study from Iran to estimate the direct risk of Neospora caninum for pregnancy loss or reproductive factors. In addition, there is no report in the literature concerning the association of N. caninum with dystocia and sex of calves. Therefore, this study was conducted on a group of dairy cows in a large intensive production system during 2011 to 2013 in southern Iran to evaluate the impact of neosporosis on reproductive performance. A total of 253 cows which were diagnosed as pregnant during the first six months of the study were followed until calving or abortion. Reproductive data were collected and N. caninum serostatus was determined using ELISA. To investigate the association of abortion with N. caninum,survival analysis was performed using Cox proportional hazard model. The N. caninum seroprevalence in the study group was 30.40% (95% CI: 27.40, 36.10). The overall abortion rate was 12.25%, significantly higher in seropositive animals (20.80%) than seronegative ones (8.50%). Results of Cox model showed that serostatus of animal for N. caninum and season had significant associations with abortion (p < 0.01). Neospora caninum did not show significant association with other factors such as dystocia and sex of calves. In conclusion, neosporosis is responsible for 12.00% excess abortion risk in infected group and more than 30.00% of abortions could be preventable by control of Neospora in study population. Therefore, control of N. caninum would reduce the economic losses caused by parasite mainly due to pregnancy loss.
Maryam Ansari-Lari; Shahram Shekarforoush; Samira Mehrshad; Hosna Safari
Volume 5, Issue 1 , March 2014, , Pages 65-68
Abstract
Salmonella spp. are important food borne pathogens worldwide that frequently infect poultry flocks. This cross-sectional study was conducted to determine the prevalence of Salmonella spp. colonization in broiler flocks in Shiraz (southern Iran) and to find the possible association of infection status ...
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Salmonella spp. are important food borne pathogens worldwide that frequently infect poultry flocks. This cross-sectional study was conducted to determine the prevalence of Salmonella spp. colonization in broiler flocks in Shiraz (southern Iran) and to find the possible association of infection status with some potential risk factors including vaccination program and use of antibiotics. During October 2009 to April 2010, a total of 40 broiler flocks were selected in slaughterhouse and 20 cloacae contents were collected from each flock. Every five cloacae contents were pooled and investigated for Salmonella spp. using appropriate culture methods. The flock was considered positive if any of the pooled samples turned positive in culture. Statistical analysis was performed using multiple logistic regression. Nine out of 40 flocks (22.50%, 95% CI: 9-36) were positive for Salmonella spp. colonization. Nearly 75.00% of flock owners reported that they used antibiotics during production period, more frequently fluoroquinolones, combination of trimethoprim-sulfonamides (TMP/SU) and tetracycline. Nearly 60.00% of the flocks which had used TMP/SU were positive for Salmonella spp. compared with 10.00% of the flocks which did not use this antibiotic (p = 0.006). Increasing flock age was associated with a decreased chance of Salmonella spp. detection (p = 0.003). In flocks which received infectious bronchitis vaccine, 36.00% were positive for Salmonella spp. whereas this was 15.00% for flocks which did not receive this vaccine (p = 0.08). Careful monitoring of antibiotics use and further studies to determine the most appropriate vaccination program in the field is recommended.
Maryam Ansari-Lari; Mehdi Mohebbi-Fani; Abbas Rowshan-Ghasrodashti
Volume 3, Issue 4 , December 2012, , Pages 233-237
Abstract
This study was designed to investigate causes of culling in industrial dairy herds in Fars province and to describe the pattern of reason-specific culling with respect to age of animal and interval from calving to culling. A total number of 9 dairy herds were selected for the study and information about ...
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This study was designed to investigate causes of culling in industrial dairy herds in Fars province and to describe the pattern of reason-specific culling with respect to age of animal and interval from calving to culling. A total number of 9 dairy herds were selected for the study and information about culling reasons, birth date, last calving date and culling date was collected for culled cows during 2005- 2006. Infertility (32.6% of all culls) was the most prevalent reason of culling followed by mastitis (6.5%). The time interval from last calving to culling averaged 240 days (SD = 176) and nearly 28% of cows were culled in the first 100 days after calving. Mean age of animals at culling was 6 years (SD = 2.7) and median was 5.7 years. In Cox proportional hazard model for calving to culling interval, infertility (hazard ratio [HR] = 0.26) showed lower risk whereas mastitis (HR = 2.40), left displaced abomasum (HR = 2.60) and peripartum problems (HR = 2.60) had higher risk of culling compared with voluntary cull. In the Cox model for age at culling, risk of culling was significantly higher for infertility (HR = 1.70), left displaced abomasum (HR = 3.15), and peripartum problems (HR = 2.10) compared with voluntary culling. In conclusion, farmers tend to keep infertile cows for longer period from calving to culling while infertile cows are generally culled at younger age. Also, early culling appeared to have a high proportion of culls in the studied herds.