Grazing-based systems are gaining momentum across the UK, offering a compelling blend of sustainability, profitability, and animal welfare. By allowing cows to graze pasture for a significant portion of the year, farmers can reduce feed costs, improve soil health, and enhance animal well-being. 

Grazing systems offer multiple benefits:

• Sustainability: Well-managed grazing improves soil health, reduces fertiliser use, enhances biodiversity and can contribute to a lower carbon footprint.
• Profitability: Grass is the most cost-effective feed source, reducing reliance on purchased concentrate and silage, leading to better margins.
• Animal Welfare: Grazing cows generally experience fewer cases of lameness and show improved health and behavioural freedom.
• Consumer Perception: Outdoor grazing aligns with consumer expectations for animal welfare and sustainable production.

As more farmers look to maximise the value of their pasture, genetics has become a critical lever for unlocking the true potential of grazing herds. At Cogent, we’re committed to helping UK dairy producers thrive in grass-based systems through advanced genetics, expert advice, and a uniquely tailored approach.

Seasonal Calving (Spring/Autumn) and Its Relevance to Genetics 

Seasonal, block calving (where cows calve within a defined period) is often used to align lactation with peak grass growth, optimising milk production from pasture. This management strategy is especially effective when paired with genetics selected for fertility, robustness and efficient milk solids production. 

The Role of Genetics in Grazing Success

Genetics underpins the long-term success of any grazing system. Grazing herds require cows that thrive on grass, are highly fertile and maintain good health with minimal intervention. Genetics determine how well cows convert grass into milk, how easily they calve, and how long they remain productive in the herd. Selecting the right genetics is essential for grazing profitability and sustainability. 

Key Traits for Pasture-Based Systems

• Fertility: Ensures high conception rates and maintains tight calving intervals in sync with grass growth.
• Robustness: Cows must thrive outdoors with minimal intervention with good mobility and conformation
• Milk Solids: High fat and protein content are prioritised over milk volume
• Health and Longevity: Traits like udder health and calving ease reduce vet costs and increase productive life

Breed choice and crossbreeding can enhance these traits, with Holstein, Jersey and Scandinavian Red genetics all offering advantages.

Grazing Indices: Making Sense of the Numbers

Grazing indices (like EBI and BW) are critical tools for optimising dairy herds in pasture-based systems. They guide genetic selection, herd management, and profitability by prioritising traits aligned with grazing efficiency, seasonal demands and sustainability.

Economic Breeding Index (EBI) – Irish Genetics

EBI is a comprehensive index designed specifically for grass-based, block-calving herds. It combines eight sub-indexes to create a complete grazing animal, focusing on high milk solids, exceptional fertility, ease of management, improved health, greater beef progeny value and both environmental and production efficiencies.

It is the gold standard for Irish grazing herds and highly relevant for UK farmers. Widely used in Ireland, EBI helps farmers breed cows that thrive on low-input, high-forage diets, ensuring resilience in variable grazing conditions.

The introduction of a national genotyping programme in Ireland will further enhance and strengthen the accuracy and robustness of EBI data. 

Breeding Worth (BW) – New Zealand Genetics

BW is an across-breed index developed and applied in New Zealand since the 1980s, aimed at selecting for profitability in pasture-based dairy systems. 

It focuses on fertility, longevity and milk solids, making it ideal for low-input, grass-based systems. A key strength of BW is its cross-breed capability, allowing farmers to compare animals across breeds, such as Holstein-Friesian and Jersey, using a single unified index. 

Widely used in New Zealand, BW is popular with farmers transitioning to or already operating grazing systems and features genetics proven to perform in challenging grazing environments. 

Spring Calving Index (SCI) 

SCI is tailored for spring block-calving herds, where maximising solids from pasture is essential. It favours higher fat/protein kilos rather than volume, aligning with seasonal grass growth. It has a strong emphasis on calving interval and lifespan to maintain tight calving blocks and reduce replacements. 

SCI is a valuable tool for UK farmers aiming to synchronise calving with spring pasture growth, supporting efficient, low-cost milk production from grass.

Autumn Calving Index (ACI)

Designed for autumn block-calving herds, for farms supplying winter milk markets, where grazing is supplemented with stored forage. It focuses on a balanced milk yield with a slightly higher emphasis on volume than SCI, reflecting winter milk premiums. It maintains focus on calving ease and udder health to withstand winter housing periods and adjusts for higher concentrate use in winter, selecting genetics that perform well in mixed feeding systems.

ACI gives UK producers a targeted selection tool for herds calving in autumn, helping optimise performance and profitability through the winter and early spring months.

How Indices Guide Bull Selection for Grazing Herds

These indices help farmers select bulls whose daughters will excel in grazing systems, ensuring high fertility, robust health, and efficient milk production. Cogent supports customers in interpreting these tools, helping them select bulls aligned with their own breeding goals to improve on farm performance, increase efficiencies and maximise profitability.

Genetic Solutions from Ireland and New Zealand for UK Grazing Herds

Both Irish and New Zealand genetics are proven performers in grazing systems and offer complementary strengths for UK dairy farmers. 

Irish Grazing Genetics

Irish genetics are selected for high fertility, strong milk solids, and excellent health. Irish Holstein-Friesians, selected under EBI, are well-suited to synchronised calving and peak grass growth. Their high submission and conception rates, along with efficient milk solids production, make them an excellent choice for block-calving herds aiming to maximise output from forage. The cow’s adaptability to differing systems means Irish grazing genetics can be used widely across a variety of UK farms.

These genetics are naturally aligned with UK conditions and are increasingly used in crossbreeding strategies to improve fertility and cow robustness without compromising solids.

New Zealand Grazing Genetics

New Zealand genetics are renowned for their fertility, longevity, and efficiency on grass. New Zealand Holstein-Friesians, Kiwi Cross and Jerseys, bred under BW, offer strong reproductive performance, resilience and efficient solids yield from low input systems. Kiwi Cross in particular, bring excellent solids per kilogram of bodyweight and thrive under low-input low-cost systems.

Their suitability to once-a-day milking and seasonal grazing makes them highly adaptable for UK farms transitioning to more forage-led systems or looking to lower input costs.

Crossbreeding Opportunities and Uses in the UK

Crossbreeding Irish and New Zealand genetics can combine the best of both worlds: high fertility, robust health, and strong milk solids. This approach is increasingly popular among UK grazing herds, and many UK farmers benefit from using both Irish and New Zealand genetics, either through crossbreeding or by selecting the most suitable genetics for their specific system and goals.

At Cogent, we are committed to providing the best solutions for each farm’s unique needs. We do not favour one genetic source over another; instead, our focus is on delivering the genetics, be it Irish, New Zealand, or a combination, that are best suited to each farm’s targets and ambitions. Our team works closely with farmers to understand their objectives and recommend the most appropriate genetics to help them achieve long-term grazing success.

Cogent’s Value-Add for Grazing Customers

Cogent provides grazing-focused breeding advice specific to the unique challenges of pasture-based systems. We offer expert guidance on bull selection and breeding strategies to match each farm’s grazing system and objectives

Support for Transition to Grazing Systems

For herds moving from housed to grazing systems, Cogent has Pasture to Profit consultants that provide guidance on pasture management along with advice on genetic changes and herd management to ensure a smooth transition.  We assist with:

• Adjusting breeding goals to align with grass-based performance
• Bull selection suited to block calving and outdoor management
• Genetic strategies for both spring and autumn calving herds

Data-Driven Insights for Pasture Performance

Utilising the LIC Tracker software allows us to review and rank animals in a herd to form a targeted breeding strategy. We also provide data-driven insights using herd data and performance records to help farmers maximise pasture performance, health outcomes, reproductive efficiency and herd productivity.

Sustainability and Herd Health Through Genetics

By selecting for robust, fertile, and healthy cows, Cogent helps farmers reduce their environmental impact and improve herd longevity.

Integrating Genetics with Grazing Management

Cogent’s partnership with LIC means we have Pasture to Profit Consultants on hand to ensure grazing plans support the wider management strategy of farms. Whether aligning genetics with pasture growth, herd productivity, or sustainability goals, we offer a joined-up approach.

Cogent’s genetics are chosen to enhance the performance and profitability of grazing herds. Key areas where genetics and grazing intersect:

• Calving pattern alignment with grass growth
• Selecting genetics to support herd mobility and condition
• Using tools to complement grazing efficiency targets

We are committed to selecting bulls specifically for the UK market, with a focus on key traits such as kilograms of milk solids, fertility, production efficiency, durability, adaptability and overall functionality. 

We have close partnerships with leading, international, grazing-focused companies like LIC, Dovea and Eurogene. By working closely with our partners, we continually build robust sire teams and ensure new, high performing bulls are introduced each year. Our ongoing work with genomic selection further accelerates genetic progress, ensuring UK grazing herds have access to sires that meet the evolving demands of modern, pasture-based dairying.

With Cogent, you can be confident that your genetic strategy is fully integrated with your grazing management, helping you achieve your farm’s unique goals now and into the future.

Call us for free on 0800 783 7258 for any help or advice with your grazing needs or contact your local Genetics Consultant.