Understanding Trichomoniasis in cattle
Trichomoniasis, caused by the protozoan parasite Tritrichomonas foetus, remains a notable reproductive disease affecting cattle herds globally. While clinical signs are often subtle, the impact on calving intervals and calf survival can be substantial. Recent research hints point to a complex mix of genetics, heifer exposure, and bull management as key factors that influence the spread and impact of the disease.
Genetics and inherited risk factors
There is growing interest in whether certain cattle lineages carry increased susceptibility to Trichomoniasis or to subtler consequences of infection, such as abortion in calves. Researchers are examining whether inherited traits influence immune response, lesion formation, or persistence of infection in carriers. Early indicators suggest that some cows may harbour the organism asymptomatically, passing risk to offspring or inadvertently facilitating transmission within pasture circles.
Farmers and veterinarians are advised to consider genetic background as part of a broader disease management plan. While genetics alone does not determine infection, it may interact with exposure and management, potentially guiding long-term breeding decisions and selection criteria to reduce herd vulnerability.
Heifers: exposure, infection, and reproductive risk
Heifers – young females approaching first breeding – are a critical focus for Trichomoniasis control. If exposed to infected bulls or contaminated environments, they may carry the infection into their first calving season, increasing abortion risk and lowering conception rates. Best practices emphasize controlled exposure scenarios, separate grazing when possible, and strict biosecurity during the pre-breeding period.
Monitoring heifers for clinical signs such as irregular cycling or early embryonic loss is essential. In herds with known or suspected exposure, veterinary guidance often includes testing strategies, optimized vaccination where available, and considering removal of persistent shedders from the breeding group to minimize onward transmission.
Bull management: crucial control point
Bull management is a central element of Trichomoniasis control. Infected bulls often shed the parasite during mating, sustaining transmission. Practices such as periodic semen testing, purchasing replacement bulls from tested, disease-free sources, and implementing safe quarantine periods for new bulls can substantially reduce risk. Some jurisdictions encourage herd-specific testing programs, with culling policies for confirmed carriers to protect female health and fertility on the farm.
Given the potential for silent infections in bulls, routine checks can be more effective than reliance on visible symptoms alone. Integrated bull management, including record-keeping of breeding success and abortion events, helps identify potential problem bulls and inform management decisions for the next breeding season.
Practical steps for reducing risk
For producers aiming to minimize Trichomoniasis impact, a multi-pronged approach is recommended:
- Source replacement bulls from tested, disease-free herds.
- Implement and adhere to quarantine and testing protocols for new additions.
- Consider genetic data as part of a broader risk assessment, alongside immunological and reproductive metrics.
- Limit exposure of vulnerable groups, notably heifers entering their first breeding, to infected environments.
- Maintain thorough records of abortions and conception rates to detect patterns early.
Communicating with a veterinarian to tailor a health program that includes testing, quarantine, and targeted genetics can help farms adapt to evolving research and optimize herd fertility.
What researchers are watching next
Experts continue to investigate how genetics, management practices, and viral or microbial co-factors may influence Trichomoniasis outcomes. The Australian Agricultural Co’s Chief Scientist notes that some calf abortions may be linked to inherited infection patterns, while dry or empty cows could cohabitate with the disease more than previously recognized. Ongoing studies aim to confirm these relationships and translate findings into practical, on-farm strategies.
