Polymorphism in neutrophil cytosolic factor 4 (NCF4) of dairy cows had mastitis in previous lactations, and the relationship with the respiratory burst.

Nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase), as a key factor in innate immunity, consists of several components, one of them is p40phox which is encoded by neutrophil cytosolic factor 4 (NCF4). Respiratory burst and reactive oxygen species (ROS) production are antimicrobial mechanisms associated with NADPH oxidase. This study evaluated the effects of g.18174 A > G and g.18270C > T single-nucleotide polymorphisms (SNP) in NCF4 on bovine mastitis and the respiratory burst capacity of neutrophils. SNPs of 160 dairy cattle were determined using a novel PCR-RFLP protocol by employing restriction enzymes, MboI and FokI. Also, the flow cytometry measured respiratory burst in 82 blood samples. Our results indicated that only g.18174 A > G SNP reduced the respiratory burst capacity. However, both SNPs were not significantly correlated with clinical mastitis. We concluded that g.18174 A > G decreases the function of NADPH oxidase. However, both SNPs were not significantly correlated with clinical mastitis.

Association of Neospora caninum with reproductive performance in dairy cows: A prospective study from Iran.

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.

The effect of Zataria multiflora extract on the clinical endometritis and reproductive indices in lactating Holstein dairy cows.

In the present study, the effect of intrauterine infusion of Zataria multiflora extract on the clinical endometritis was investigated. Vaginal examination, transrectal palpation and ultrasonography were used to inspect the genital tract at 30-40 days in milk and two weeks later the same approach was applied. Cows with clinical endometritis were randomly divided into three treatment groups: Z. multiflora extract (n = 56), penicillin + streptomycin (pen + strep, n = 55), and placebo (n = 20). Cervical cytology, reagent strip test and cell counting by means of Neubauer hemocytometer were carried out in both examinations. Clinical cure rate of cows with endometritis of score 1 were 45.5, 34.5 and 53.6% in placebo, pen + strep and Z. multiflora, respectively. Clinical cure rate of cows with endometritis of score 2, 3 were 66.7, 84.6 and 56.0% in placebo, pen + strep and Z. multiflora, respectively. Overall, proportions of successfully treated cows were 55.0, 58.2 and 54.7% in placebo, pen + strep and Z. multiflora, respectively (p > 0.05). In placebo, none of the parameters were significantly different between first and second examination, while we found the significant differences in percentage of neutrophils and leukocyte esterase activity in other groups (p < 0.05). First service conception rate of cows was higher in Z. multiflora compared to other groups; however, this difference was not significant. In conclusion, pen + strep and Z. multiflora extract can be effective on the clinical endometritis and may improve reproductive performance. The extract of Z. multiflora can be useful as an alternative therapy for treatment of clinical endometritis in lactating dairy cows.

Characterization of single nucleotide polymorphism in the 5'-untranslated region (5'-UTR) of Lactoferrin gene and its association with reproductive parameters and uterine infection in dairy cattle.

Uterine infection is one of the reproductive diseases that can have disturbing postpartum uterine health in cattle. Therefore, identification of resistant genotypes to uterine infection is important. Lactoferrin (LF) is one of the major antimicrobial compounds in the normal uterine discharges of cows. We hypothesized that allelic diversity in LF gene may contribute to susceptibility or resistance to uterine infection. We investigated the single nucleotide polymorphism genes identified in the 5' untranslated region (5'-UTR, position +32) of the LF gene using Allele-specific PCR method in cows with and without uterine infection. Blood samples were collected from 89 multiparous Holstein dairy cows with a history of uterine infection (n = 51), and cows without disease as the control group (n= 38). The results indicated the presence of different proportion of polymorphisms (G > C) in the 5'-UTR area of cows in the all groups. The results of Allele specific PCR was in complete agreement with sequencing method. Statistical analysis did not show any statistically significant correlation between disease and SNP in 5'-UTR. While, there was a significant difference in the mean of reproductive parameters of cows without polymorphism compare to those of with SNP in 5'-UTR. Cows with +32:CC genotype and +32:GC genotype (cows with SNP in UTR) had lower average of services per conception and days open compared to cows with the +32:GG genotypes. However, no significant difference in the calving to first service was found between these genotypes. Further studies will be required to determine critical SNPs in LF gene and status of the risk of uterine infection and embryo survival in cows.

Causes of culling in dairy cows and its relation to age at culling and interval from calving in Shiraz, Southern Iran.

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.