Over the past few weeks, on many occasions I have been asked to check cows that were either not coming in heat or not holding to service, or simply cows that are 42 or more days since calving with no sign of heat.

This can be done using a scanner, by manual examination or a combination of both.

In the case of cows not being observed coming in heat, my next exercise is to individually examine them. This examination can reveal a lot.

The most common conditions encountered are as follows:

  • Dirty cows – these cows have infections in their wombs which need treatment, they are not coming in heat because the infection in the womb sends a signal to the brain that there is something there which could be a pregnancy.

    • The infection needs local treatment and the cow needs hormonal treatment to induce a heat.

  • Cows that have had difficult calving – this has left the vagina partially paralysed. These cows tend to pool urine at the anterior part of the vagina which results in chronic infection and very poor reproductive performance. Treatment is very difficult and oftentimes they are better left until nature does the healing and tone returns to the vagina.
  • Cows with inactive ovaries – these generally are heavy milkers with perfectly clean wombs, but are putting all their energy into production. These cows need hormonal treatment to kickstart cyclical activity.
  • Cows with what is known as a “corpus leuteum” on the ovary – these cows probably have had one or more cycles which went unnoticed and will respond very well and quickly to hormone therapy.
  • Silent heats – cows that are actually in heat at the time of examination, but yet they are not showing the relevant signs of heat.
  • Cows that are actually pregnant – somehow the records are wrong for one reason or another.

    • The single biggest problem with many high-producing cows is silent heats, the cows are actually coming into heat but not showing the signs, or showing heat for such a short period of time that they are not being noticed.

    The use of a vasectomised bull is an excellent aid to heat detection, but treat such an animal as an entire bull for safety reasons. They can become quite aggressive and dangerous.

    If it is late in the season and a good percentage of cows are in calf, there is nothing like a bull to clean up.

    On occasion one is asked the question: “Should I cull that cow?”

    In answering that question one must take the whole picture into account, a cow may well be worth further time and treatment on some farms, where as on others she may be a nuisance, depending on cow numbers available help, etc.