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 optimize 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

In the US, Holstein heifers typically reach maturity between 9 and 11 months of age, but should not be bred until later. The ideal age at first calving is around 22 months, so first breeding should occur at about 13 months. At that time, heifers must be physically mature. Holstein heifers, for example, should weigh approximately 45% of the weight of an adult cow.

Studies show: Heifers with a higher body weight at calving (approx. 1,150 lbs) can produce up to 1,760 lbs more milk during their first lactation than lighter animals (approx. 925 lbs). 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. Proestrus

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

2. Estrus (Standing Heat)

This phase lasts 12–18 hours in high-producing cows. Ovulation occurs 25–30 hours after the beginning of estrus, 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. Metestrus

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

4. Diestrus (Interestrus)

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 July 30, triggering a heat alert. After entering estrus, the system identified and displayed the optimal insemination window.