Which technique is commonly used to detect cows in heat in dairy herds?

• A. Milk yield monitoring
• B. Tail paint
• C. Body temperature monitoring
• D. Ear tagging

Answer: (B)

Detecting cows in heat relies on a clear behavioral cue—standing heat is when cows are receptive and most ready for insemination. Tail paint is a simple, effective way to spot this. A line of paint is applied to the base of the cow’s tail. When cows are in heat, they’re mounted by others, which rubs or wipes the paint away. The absence of paint on the tailhead becomes a quick, visible signal that the cow is in estrus, so insemination can be timed correctly.

Tail paint is popular because it is inexpensive, easy to apply across a large group, and provides day-to-day monitoring without special equipment. In contrast, monitoring milk yield mainly reflects production or health issues rather than heat signs, body temperature monitoring is less practical for routine heat detection on many farms, and ear tagging is used for identification and records rather than real-time heat detection.