Prevalence of bovine trichomonosis and associated risk factors in bulls from Spanish beef herds

Molecular prevalence and phylogenetic confirmation of bovine trichomoniasis in aborted cows in Iraq

Background and Aim

Bovine trichomoniasis, caused by Tritrichomonas foetus, is a venereal disease that is distributed in many countries, including Iraq. Compared with other abortive infectious diseases, prevalence of T. foetus is expected to be relatively low in the field by veterinarians. This study aimed to estimate the prevalence of T. foetus in aborted cows by conventional polymerase chain reaction (PCR) and phylogenetic analysis of local T. foetus isolates was documented in the National Center for Biotechnology Information as the first sequenced isolates from Iraq.

Materials and Methods

Vaginal fluids were collected from 62 aborted cows and examined by PCR. Data were reported for the following parameters: Vital signs (body temperature and respiratory and pulse rates), age (<4, 4-8, and >8 years), reproductive health status (premature calving, embryonic death, pyometra, and healthy newborn), breed (pure or crossbred), type of breeding (natural or artificial), bull-to-cow ratio (1:<10, 1:10-20, and 1:>20), contact of cow with bull(s) from other farmers (yes or no), and contact with stray animals (dogs and cats).

Results

A total of 20.97% of aborted cows were positive for T. foetus. Phylogenetic analysis for 10 positive local T. foetus isolates demonstrated high identity with the Thai (MN560972.2) and Chinese (MH115435.1) isolates, with an identity range of 98.8%-99.5% and 98.6%-99.3%, respectively. Clinical data showed that the vital signs differed insignificantly between cows positive and negative for T. foetus. Prevalence and risk of infection increased significantly in <4-year-old, early calving, embryonic death, crossbred, and naturally inseminated cows that had direct contact with bulls from other farmers, and contact with stray animals. Fetal pneumonia and death of premature calves were significant among positive aborted fetuses.

Conclusion

Tritrichomonas foetus is highly prevalent in aborted cows in Iraq and phylogenetic analysis demonstrated an identity between the local and global isolates, that is, Thai and Chinese, of cats.

A new inactivated Tritrichomonas foetus vaccine that improves genital clearance of the infection and calving intervals in cattle

Bovine trichomonosis is a sexually transmitted disease that is a primary cause of early reproductive failure in cattle. The aim of the present study was to develop a vaccine formulation based on Tritrichomonas foetus trophozoites inactivated by lyophilization and Quil-A-adjuvanted. The safety, immunogenicity and efficacy of this new vaccine formulation (Trichobovis^®) administered by two routes (subcutaneous: SC, and intravulvar: IVU) were compared with a commercial vaccine (TrichGuard^®) in a well-established experimental bovine model of genital T. foetus infection. The new vaccine was considered safe in cattle because only mild local reactions were found in the vaccination area, which disappeared 3 weeks after administration. Cows immunized with Trichobovis cleared the infection faster than the non-immunized/challenged group (27–28 vs. 60 days; P < 0.05). Not significant differences were observed with the commercial vaccine respect to the positive control group, or between SC and IVU routes. The new vaccine stimulated high serum anti-T. foetus IgG and genital IgA levels and generated an IgG booster effect similar to TrichGuard. IgA levels were associated with significantly earlier genital clearance of T. foetus in cows immunized with Trichobovis by SC route (G1A) or TrichGuard (G2). The strongest association was found in the group G1A on day 14 post-infection (p.i.) (r = −0.74) and in G2 on day 35 p.i. (r = −0.71). The efficacy of vaccination using Trichobovis on the reproductive performance was also investigated under field conditions in a herd where T. foetus was present. The calving intervals were significantly reduced by 45.2 days (P < 0.05), calves were born 28 days earlier (P < 0.05) and an increase of 8.7% in the calving rate (P > 0.05) was observed in the vaccinated group. These results demonstrate that Trichobovis improved the reproductive performance under field conditions in herds where T. foetus infection is present.

Not gone but forgotten: Tritrichomonas foetus in extensively-managed bulls from Australia's Northern Territory

Bovine trichomonosis, caused by infection with the protozoan parasite Tritrichomonas foetus, is globally recognised as a cause of reproductive failure in cattle. Maintained in clinically normal bulls, T. foetus infection results in infertility and abortion in infected cows. In Australia’s Northern Territory (NT), logistical limitations associated with extensive livestock production inhibit wide-scale testing and diagnosis, allowing the parasite to persist undetected. In the present study, T. foetus was detected in 18/109 preputial cultures collected from bulls on a property in the NT with a history of low birth rates and reproductive failure using real-time PCR testing. Of the T. foetus-positive samples, 13/18 were genotyped using the internal transcribed spacer regions (ITS1 and ITS2) and the 5.8S rDNA unit. Selected samples were further characterised using the protein-coding genes of cysteine proteases (CP-1, 2, 4–9) and cytosolic malate dehydrogenase 1 (MDH-1) to determine if the isolates were ‘bovineʼ, ‘felineʼ or ‘Southern Africaʼ genotypes. All samples were 100% identical to the T. foetus ‘bovine’ genotype across all markers. This is the first reported case of trichomonosis in Australian cattle since 1988 and is a reminder that T. foetus should be considered whenever reproductive failure occurs in extensive cattle systems.

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The first published case of bovine trichomonosis in Australia since 1988.

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Extensive genotyping of two isolates using 10 divergent markers.

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Isolates were determined to be 100% homologous with the Tritrichomonas foetus ‘bovine’ genotype.

Prevalence of Bovine Genital Campylobacteriosis, Associated Risk Factors and Spatial Distribution in Spanish Beef Cattle Based on Veterinary Laboratory Database Records

Bovine genital campylobacteriosis (BGC) is a sexually transmitted disease that causes early reproductive failure in natural breeding cattle that are managed extensively. The aim of this study was to assess the BGC prevalence in Spain from 2011 to 2019 using data collected cross-sectionally from the diagnostic reports issued by the SALUVET veterinary diagnostic laboratory from a total of 5,182 breeding bulls from 1,950 herds managed under “dehesa” systems (large herds within fenced pastures and all-year breeding season) or mountain systems (smaller herds with seasonal breeding management and grazing in communal mountain pastures). Infection was detected by PCR in 7.7 and 12.2% of the bulls and herds tested, respectively. The “dehesa” herd management system (OR = 2.078, P = < 0.001, 95% CI = 1.55–1.77), bovine trichomonosis status of the herd (OR = 1.606, P = 0.004, 95% CI = 1.15–2.22), and bulls ≥3 years old (OR = 1.392, P = 0.04, 95% CI = 1.01–1.92) were identified as risk factors associated with Campylobacter fetus venerealis infection. We also studied the high-risk areas for circulation of the infection in extensive beef cattle herds in Spain, showing four significant clusters in “dehesa” areas in the south-western provinces of the country and a fifth cluster located in a mountain area in northern Spain. The results obtained in the present study indicate that BGC is endemic and widely distributed in Spanish beef herds. Specifically, “dehesa” herds are at greater risk for introduction of Cfv based on relatively high local prevalence of the infection and the use of specific management practices.

Survey of beef bulls in Brazil to assess their role as source of infectious agents related to cow infertility

Poor reproductive performance in beef cattle caused by infectious agents results in major financial losses as a result of reduced pregnancy rates and extended calving intervals. Bulls can be subclinical chronic carriers of bacterial and protozoal agents involved in cow infertility, such as Campylobacter fetus subsp. venerealis, Ureaplasma diversum, Mycoplasma bovigenitalium, Mycoplasma bovis, and Tritrichomonas foetus. Bulls harbor these microorganisms in their preputial crypts and transmit the agents to cows during natural mating. To obtain an overview of the etiologic agents in the preputial mucus of bulls, we aimed to identify, by PCR assay, C. fetus subsp. venerealis, M. bovis, U. diversum, M. bovigenitalium, and T. foetus in Brazilian bulls from farms with high infertility rates. We collected preputial mucus from 210 bulls on 18 beef cattle farms in Brazil between 2019 and 2020. We found at least one of the infectious agents that we were studying in bulls on 16 of the 18 beef cattle farms tested. We detected at least one infectious agent from 159 of 210 (76%) bulls tested, namely C. fetus subsp. venerealis, M. bovis, U. diversum, M. bovigenitalium, and T. foetus in 87 (55%), 84 (53%), 45 (28%), 28 (18%), and 1 (0.6%) animal, respectively. We found 95 bulls (60%) positive for only 1 etiologic agent (single infection) and 64 bulls (40%) carried multiple agents. Our results demonstrate the occurrence of bacterial and protozoal infectious agents that may be related to infertility in Brazilian beef cattle herds.

The Effect of Stress on Reproduction and Reproductive Technologies in Beef Cattle-A Review

Researchers have contributed by increasing our understanding of the factors affecting reproduction in beef, mainly physical health and nutrition aspects, which have been main concerns during decades. Animal welfare is of outmost relevance in all animal production systems and it is strongly associated to stress. Stress responses involve endocrine, paracrine and neural systems and the consequences of this stress on the reproductive efficiency of specifically, beef cattle and bulls, need to be highlighted. We, therefore, describe the fundamentals of stress and its quantification, focusing in beef herds, reviewing the highly valuable pieces of research, already implemented in this field. We examine major factors (stressors) contributing to stress in beef cattle and their effects on the animals, their reproductive performance and the success of reproductive biotechnologies. We include terms such as acclimatization, acclimation or temperament, very relevant in beef systems. We examine specifically the management stress due to handling, social environment and hierarchy or weaning effects; nutritional stress; and thermal stress (not only heat stress) and also review the influence of these stressors on reproductive performance and effectiveness of reproductive biotechnologies in beef herds. A final message on the attention that should be devoted to these factors is highlighted.

Multilocus analysis reveals further genetic differences between Tritrichomonas foetus from cats and cattle

Tritrichomonas foetus isolates from feline and bovine origin has been previously shown to carry a certain degree of genetic heterogeneity. Here, novel candidate molecular markers were developed by means of multilocus sequence typing of the gap2 gene (encoding for T. foetus glyceraldehyde-3-phosphate dehydrogenase), ITS region, the TR7/TR8 variable-length repeat and microsatellite genotyping. These markers were used to characterize T. foetus field isolates from bulls and domestic cats and to compare phylogenetically with the following ATCC isolates: T. foetus isolated from cattle and pig (syn. Tritrichomonas suis), Tritrichomonas mobilensis, Tetratrichomonas gallinarum and Pentatrichomonas hominis. Among them, TFMS10 and TFMS7 were found to be the most polymorphic markers. Moreover, an 809 bp fragment of the gap2 gene was successfully amplified from all the trichomonads included in this study and the sequence analysis revealed differences between T. foetus porcine and feline genotypes and T. mobilensis in comparison to the bovine T. foetus ATCC isolate. The TR7/TR8 repeat pattern was not reproducible, being only consistent the fragments of approximately 110 and 217 bp. Sequence analysis of the latter revealed the existence of 3 SNPs resulting in 98.6 % homology between bovine and feline isolates. A search for similar sequences was carried out to develop a Restriction Length Fragment Polymorphism analysis. A 503 bp region, named TF1, revealed the existence of two BbvI restriction enzyme sites that were able to generate different length fragments for T. foetus feline and bovine isolates. Finally, the neighbour-joining analyses showed that T. foetus porcine genotype clusters together with bovine genotype, whereas T. mobilensis and the feline genotype form a separate cluster.