Unit 5: Managing Herd Fertility and Replacements

Heat detection

Heat detection in beef cows is the process of identifying when a cow is in oestrus (heat) — the period when she is fertile. Detecting this accurately is important for successful breeding, whether through natural mating or artificial insemination.

Here are the signs:

Standing to be Mounted:

The most reliable sign that a cow is in heat is when she stands still and allows other cows or a bull to mount her. This is often referred to as the “standing heat”.

Mounting Other Cows:

Cows that are close to or in heat may try to mount other cows. However, mounting others is less reliable as a sign than standing to be mounted.

Restlessness and Increased Activity:

Cows in heat are often more active, walking around more, and may seem restless. They may move away from the herd or vocalise more than usual.

Clear Mucus Discharge:

A cow in heat may show a clear, stringy mucus discharge from the vulva. This can often be seen hanging from the back of the cow or observed on her tail.

Swollen and Red Vulva:

The cow’s vulva may appear swollen, moist, and slightly reddened during heat.

Sniffing and Licking Other Cows:

Cows in heat may sniff and lick the genital area of other cows.

Chin Resting:

A cow in heat may rest her chin on the backs of other cows.

These are all visual signs that any herdsman can pick up on when observing his cows daily.

Methods to Detect Heat:

Visual Observation

The most traditional method is to spend time observing the herd, especially early in the morning and late in the evening when cows are more active.

Heat Detection Aids

Tail Paint or Chalk: Applied to the tail head, this rubs off when the cow is mounted, helping to identify cows in heat.

Kamar Heat Detectors: These are pressure-sensitive devices that change colour when the cow is mounted.

Activity Monitors: Electronic devices such as pedometers or activity collars monitor increased movement and activity associated with heat.