6 min · agnelage · 4/12/2026
How the Birth Alarm works: SMS lambing alert
The Birth Alarm is a Swiss device that warns the farmer 30 min before lambing via SMS. Here is how it works.
Watching every night through lambing season costs sleep and increases lamb mortality. The Birth Alarm Premium Plus, part of the OVIHANDLING range, removes that stress by sending an SMS as soon as uterine contractions are detected — typically 30 minutes before delivery.
The vaginal sensor
Inserted 7 to 10 days before term by the vet or trained farmer, the medical-grade silicone sensor (T-shape) continuously emits a short-range 433 MHz FM signal. It is waterproof, biocompatible and stays in place until expelled by contractions — which triggers the system.
The transmitter unit
Attached to the halter or collar, the GSM unit (12 × 6 cm, 180 g) wakes when the radio signal is lost (= start of expulsion), validates for 30 s to avoid false positives, then sends an SMS to up to 4 numbers.
- Battery life: 60 days on rechargeable Li-ion
- GSM 2G/4G — standard SIM not included
- IP67: weatherproof for damp barns
- Configured by SMS or mobile app
Setup and activation
1. Insert the sensor 7-10 days before due date. 2. Activate the GSM unit with SMS 'ON'. 3. The unit confirms with 'system active'. 4. At lambing, expulsion triggers an SMS 'BIRTH ALARM — birth imminent'. 5. You have 20 to 40 minutes to intervene.
Documented reliability
Across 4 years on 200 OVIHANDLING farms (internal data), Birth Alarm prevented 23 % of neonatal mortality linked to unassisted difficult lambing. The cost (~£820 inc VAT) is recouped on the first ewe saved.
Takeaway
Birth Alarm turns lambing into a controlled routine. Paired with an OVIHANDLING lambing pen, it guarantees the farmer is present at the critical moment without standing watch.
Expertise
Jannes Hendriks van Warbij
Founder of OVIHANDLING, livestock farmer and specialist in sheep handling and weighing equipment
This guide is written by Jannes Hendriks van Warbij for OVIHANDLING, a French company based at Les Calies 4, 16420 Lesterps, France, which has designed, manufactured and supplied handling, sorting and weighing equipment for sheep, cattle and goats for more than 20 years. The recommendations come from daily on-farm use of this equipment and from feedback by our farming customers.
A question on a specific point? Write to us: contact@ovihandling.com
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