Heat Detection with smaXtec: Reliable Insights for Better Reproduction

With smaXtec, you can reliably and accurately detect heats without time-consuming observation. This allows you to increase reproductive success, save costs and optimise calving intervals – around the clock, all year round.

The financial success of a dairy farm heavily depends on reproductive performance. But as herd sizes grow and genetics evolve, identifying the optimal insemination time becomes increasingly challenging. With automatic heat detection from smaXtec, you can reliably detect heats, inseminate cows at the right time and improve reproductive outcomes.

First heat: Get it right from the start

Heifers typically reach puberty between 7 and 10 months of age, but should not be bred until later. The ideal age at first calving is around 24 months, so first breeding should occur at about 15 months. At that time, heifers must be physically mature. Holstein heifers for example should weigh around 400–430 kg, or approximately 55% of the weight of an adult cow.

Studies show: Heifers with a higher body weight at calving (approx. 520 kg) can produce up to 800 kg more milk during their first lactation than lighter animals (approx. 420 kg). On the other hand, breeding too late (e.g., at 27–28 months) can lead to ovarian fat deposits, reducing pregnancy rates.

The four phases of heat

To identify the ideal insemination time, it is essential to detect the start of heat as early as possible. Depending on the phase, different signs of heat can be observed. The heat cycle is divided into four phases:

1. Pro-oestrus

Early behavioural changes such as sniffing, mounting other animals and thick, sticky discharge occur. Milk letdown may be inhibited.

2. Oestrus (Standing Heat)

This phase lasts 12–18 hours in high-producing cows. Ovulation occurs 25–30 hours after the beginning of oestrus, roughly 6–12 hours after visible signs subside. Sperm require about 6–8 hours after insemination for capacitation, while egg viability declines significantly 6–12 hours after ovulation. Thus, the best time to inseminate is approximately 6–12 hours before ovulation, toward the end of standing heat, ensuring optimal overlap between sperm function and egg viability.

When using sexed semen, the insemination window shifts slightly later. A delayed insemination may improve conception rates.

3. Metoestrus

The cow is no longer receptive, signs of heat fade and mucus becomes very viscous.

4. Dioestrus (Interoestrus)

This phase lasts about 14 days and no signs of heat are visible.

Improve heat detection with smaXtec

With smaXtec, heat detection becomes significantly easier and more effective. The key advantages at a glance:

• Accurate heat detection without the need for visual observation.
• Reliable detection of silent heats.
• Automatic alerts enable precise, timely insemination.
• Higher conception rates thanks to individual cow data and automated calculation of the optimal insemination time.
• Improved herd fertility through early detection of fertility issues and targeted intervention.

smaXtec heat detection example curve

The smaXtec system detects heat based on characteristic changes in activity. In the example shown, activity (red curve) increased sharply on 30 July, triggering a heat alert. After entering oestrus, the system identified and displayed the optimal insemination window.