Angus Cow

Heat Detection Tips

Artificial insemination is one of the best tools available today for a breeder wanting to increase the genetic merit and production of his herd. The cow herd must be on a rising place of nutrition for an artificial breeding program to be successful.

Early Signs – Before the Female is in Standing Heat

  • A small string of mucus dripping out of a reclining cow is not too common and should not be confused with the more copious mucus seen when a cow is in heat.
  • Bawling when other herd mates are quiet. This sign is observed quite often among heifers, but not often among cows.
  • The cow is more alert and observant.
  • She walks in a rapid business-like way.
  • She is standing when all other herdmates are lying down.

Signs to Look for in a Female Standing in Heat

  • A cow may walk through her herdmates sniffing as a bull might do as he checks cows.
  • She will attempt to ride other cows not in heat.
  • The cow stands still when other cows mount her. This is the most obvious sign of all. If there are a large number of cows in heat in the herd, there will probably be more than one cluster of cows riding each other. A cow in heat may also ride other cows in heat, so how do you tell if the cow doing the riding is in heat?

This can usually be determined by watching their activity for a few minutes. If you do not see the other signs of heat in the riding cow she is probably not in heat.

If still in doubt about the status for the individual, sort her off with the other cows in heat. If she is in some stage of heat she will stay close to them, is she is not she will not show a continuous interest in them.

  • She gives signs. She will place her head on the rump of another cow, and when she rides another cow, copious strings of mucuc will often be expelled.
  • Mucus can often be seen on the side of the tail or rump.
  • Cows in heat will group together and stand closer to each other than they normally do. If they are touching each other or only a few inches away from each other, they are probably in heat.
  • Several bull calves follow a cow and attempt to ride her. Occasionally a heat detector will encounter an oversexed female that will be with the in-heat group for two or three days following heat.

The short cycle cow, that will come back in heat in a week or 10 days after she was first heat detected may also be encountered. These should be inseminated again.

Signs that a Cow has just Gone Out of Heat

With some heat cycles only lasting 12 hours some cows are easy to miss when in heat, but it is easy to tell when they have been in heat during the night.

  • Wet or matted hair, especially over the top of the shoulders.
  • Hair on the tail or rump may be slightly matted where mucus has dried.
  • Mud on the hips or hair rubbed off the hips where other cows have ridden.
  • A fresh brand on the hip will be bright red for a few hours.
  • A cow that has been riding all night while in heat may be tired by morning and be one of the few cows that will be lying down.
  • Mucus will often be expelled as a breeding tube is inserted if the cow has been in heat.
  • A string of blood on the side of the tail or rump indicates the cow was in heat two or three days ago. If you did not detect her, you missed her.

If cows are not synchronised, an average of five per cent of each group of cows should come into heat each day.

If this number is not being achieved, producers need to consider whether their cows are getting enough to eat, and whether they are in good enough condition to cycle.

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