How genetics helps reduce antibiotics and hormones in dairy herds

In recent years, the dairy industries in Denmark, Sweden and Finland have gained international attention for their low use of antibiotics in livestock production.

According to the latest report from the European Medicines Agency on veterinary antimicrobial consumption, these Nordic countries remain among the lowest users of antibiotics in food-producing animals in Europe. Strict veterinary regulations and a long-standing focus on preventive herd management have played an important role in achieving this result.

However, regulations alone do not explain the success. A key factor has been the integration of health traits into breeding goals for decades.

By selecting animals with stronger natural resistance to diseases, dairy farmers can reduce the number of health problems that require treatment. The result is a production system built on prevention rather than medication.

The Hoof health index has two sub-traits covering the infectious hoof disorders often treated with antibiotics — Digital dermatitis + interdigital dermatitis and Verrucose dermatitis + interdigital hyperplasia — and focusing on improving these traits can help reduce the need for antibiotics by breeding cows that are naturally more resistant to infectious hoof diseases.

The data behind the Hoof health index is the records on hoof disorders collected by hoof trimmers during the first three lactations. Hoof trimmers register all “findings” or all “no findings” on each hoof of every cow they trim into three different categories:

• 0 - no disease
• 1 - mild disease
• 2 - severe disease

What makes the Hoof health index unique is that in the Nordic countries, we register actual disease cases and don’t just rely on correlated traits - like Feet & Legs conformation. A feet and legs index, on its own, is not a good enough predictor for improving hoof health.

The correlation between the Feet & Legs index and the Hoof health index is around 14%. Only one out of five times would you succeed in improving hoof health if you rely on Feet & Leg conformation. Therefore, registrations of actual diseases are a more accurate breeding value base. Electronic hoof trimmer data is collected for 50% of cows in Denmark, Sweden, and Finland. That results in a high reliability of breeding values for hoof health.

Importantly, genetic improvement is permanent. Each generation inherits stronger health traits, meaning that progress accumulates over time. What begins as a breeding decision today can deliver long-term improvements in herd health, productivity and farm profitability.

In some countries, hormonal synchronization protocols are commonly used in dairy herds. These protocols help facilitate timely breeding, improve reproductive efficiency, and support herd management by controlling the timing of estrus and ovulation. This allows groups of cows to be inseminated predictably, reduces the need for visual heat detection, improves conception rates, and helps maintain uniform calving intervals.

In the Nordic countries, hormones are not used routinely on groups of animals. They are administered only to individual cows when necessary, typically to treat reproductive disorders under veterinary supervision. This approach emphasizes prevention over routine hormonal intervention.

Reducing the need for hormone treatments starts with strong, healthy cows. Instead of relying on interventions to correct reproductive problems, farmers can use breeding to prevent them in the first place. The General health index in NTM is a powerful tool for this, as it includes two key sub-traits: early reproductive disorders, such as retained placenta, and late reproductive disorders.

The General Health index is calculated based on veterinary health records from the first three lactations of all registered cows in Denmark, Finland, and Sweden – over 90% of cows in the Nordics. This results in highly reliable breeding values for general health.

By selecting bulls with high breeding values for General health, dairy herds can achieve fewer reproductive complications naturally. Healthier cows not only conceive more easily and maintain pregnancies with fewer interventions, but they also require less hormone treatment, lowering costs and improving animal welfare. Strong genetics for general health mean healthier cows, better fertility, and a more productive, resilient herd over the long term. The General health index in NTM shows a strong positive correlation with the Daughter Fertility Index — 38% for Holsteins.

Higher milk production is genetically linked to lower daughter fertility, with a negative correlation of -21% between the Production Index and Daughter Fertility Index in Holstein.

With the right breeding strategy, you can still improve both traits at the same time. VikingGenetics sires are selected for strong genetic progress in both production and fertility, supporting more efficient and profitable herds.

Genetics plays a key role in supporting natural fertility across the herd. By selecting animals with strong reproductive traits, farmers can achieve high conception rates and regular reproductive cycles without synchronization protocols. VikingGenetics cows set the industry standard in this regard, combining robust fertility, high reproductive efficiency, and excellent herd health — all naturally, without routine hormone use.

Fertility is closely linked to a number of other traits. Genetic progress in these traits will support your efforts to maintain high reproductive efficiency in your herd.

Explore the strong positive correlations between the Daughter fertility index, other traits in the Nordic Total Merit index, and NTM itself. Click “+” to view the figures.

A common concern among dairy farmers is whether focusing on health and reproduction traits could reduce production of milk and solids. The Nordic breeding philosophy shows that health, reproduction, and survival do not have to be sacrificed for higher production. By focusing on breeding for higher fat and protein yield — not just more milk — farmers create more balanced and profitable cows.

Before the year 1980, the Nordic countries had a Production Index, Calving Index, Daughter fertility Index, Udder Index and Milkability Index. By 1982, the Nordic Total Merit (NTM) included a Mastitis Resistance index. In 1987, a General Health index that referred to metabolic and reproductive diseases was included in the NTM.

Direct selection is a central component of the Nordic breeding programme and involves selecting directly for the traits we wish to improve. Instead of using indirect indicators or correlated traits, selection is based on breeding values for specific traits, such as daughter fertility, udder health, hoof health and general health.

In the Nordic countries, effective direct selection is made possible by comprehensive and systematic data collection, including veterinary records, production data and reproductive information among others. The high data quality and coverage ensure breeding values with a high degree of reliability, making it possible to achieve stable and sustained genetic progress.

A cow with strong hoof health, robust general health, and resistance to mastitis will stay in the herd longer, maintain consistent production, and contribute to both sustainability and profitability. This approach demonstrates that well-being and performance go hand in hand, giving farmers cows that are healthier, more fertile, and economically valuable over the long term.