Catching heat: 6 signs worth watching for

Every heat you miss pushes the next breeding chance about 21 days down the road. On a cow that means a later calving, a longer dry period, and weeks of milk you never sell. Across a herd, missed heats are one of the quietest, most expensive leaks on a dairy farm — and they rarely show up in any record because, by definition, nobody noticed.

What to watch for

Standing heat — when a cow holds still to be mounted by herdmates — is the clearest signal, but it lasts only a few hours and often happens at night. The supporting signs are what give you a wider window:

• Mounting other cows, or standing to be mounted
• Clear, stringy mucus discharge from the vulva
• Restlessness, bawling, and pacing the fence line
• A sudden, unexplained drop in milk that day
• Swelling or reddening of the vulva
• Mud or rub marks on the hips and tail head from being mounted

Two cheap habits that catch most of them

First, watch at the right time. Most standing activity happens in the early morning and late evening when it is cool, not in the heat of the day when you are usually out among the animals. Ten focused minutes at dawn and dusk beats an hour at noon.

Second, write it down the moment you see something — even an "I think she might be coming on" note. A heat you log today tells you when to look hard again in roughly 18 to 24 days if she does not get served. That pattern is impossible to hold in your head across a whole herd, but trivial once it is written down.

That is the whole idea behind logging in Herd Signals: the app does the counting, so a maybe-heat today becomes a reminder to check her again at the right time — and a cow who should have cycled but has gone quiet gets flagged before she costs you a season.