Bruce Jackson, DPIPWE
Vibrio (Campylobacter fetus venerealis) and Trich (Tritrichomonas foetus) are two reproductive diseases that may be responsible for high returns to service, poor pregnancy testing percentages and cow abortions. Pregnancy rates in virgin heifers are usually much lower than for adult cows in affected herds.
These two diseases are spread by infected bulls. AI centres should test all bulls before collecting semen, so AI semen should be free from Vibrio and Trich. If bulls are used to mop up after AI, the impact on overall fertility may not be spectacular but is still a preventable loss.
Infected bulls appear normal, but the infection lives in the sheath, from where it is spread to females at mating. Once inside the cow or heifer’s reproductive tract the disease kills the growing calf, resulting in early to mid-term abortion. Many of these abortions won’t be detected, as they occur before pregnancy testing and the tiny developing foetus may be resorbed or ‘slipped’ in the paddock and cleaned up by crows.
Although there are several possible causes for low pregnancy rates and abortions, very few farmers currently test for Vibrio or Trich. Recent data from the Animal Health Laboratory in Launceston confirms that these two disease are present in cattle herds in Tasmania.
There are simple ways to protect your herd from these diseases, including vaccinating bulls against Campylobacter, using “Vibrovax®’, pregnancy testing and culling all empty females, culling any female that was pregnancy tested in calf and does not calve, and/or using only young (less than 3 years old) or virgin bulls.
Speak with your local veterinarian if you are concerned that your cattle may be affected by Vibrio or Trich, particularly if you are experiencing less than ideal pregnancy rates or if you notice any abortions.