Our first visit to Jonny Slack's operation finds the farm in full spring mode, with calving well underway and grazing conditions ideal

Dolphenby Farm is located in the heart of Eden Valley in Cumbria, where rolling fields provide ideal grazing conditions for the cross-bred dairy cows. The operation, established 14 years ago in 2011, is a thriving example of how strategic breeding decisions and innovative management can transform a grazing operation.

Co-owned by Jonny Slack, who worked his way up from relief milker to farm manager before taking the leap to ownership two years ago, this 550-cow dairy herd operates under a 12-week spring block calving system, combining New Zealand and Irish genetics to maximise production and profitability.

This visit marks the start of a year-long series following Dolphenby Farm through its seasonal cycles, showcasing the challenges and successes of running a modern grazing-based dairy farm.

Spring Calving in Full Swing

The farm's 12-week spring block calving is well underway, with strong calf health and promising early lactation performance. Thanks to favourable weather conditions, grazing is off to a strong start, setting the stage for a productive season. However, challenges from the previous year's grass quality impacted conception rates, prompting Jonny to refine his grazing management strategy alongside his breeding decisions.

The newest arrivals represent a thoughtful blend of genetics that has evolved over time. Originally developed as an LIC herd with predominantly New Zealand genetics, the farm began incorporating Cogent’s Irish genetics four years ago to optimise production. "The past two years have seen us primarily using Irish genetics, but we're now strategically bringing NZ genetics back into the mix to maintain the advantages of both lines," Jonny notes.

This season's calvers come from sires including Victor, Magnifico, and Lion King, with Jonny particularly enthusiastic about the results: "Magnifico heifers have been exceptional in their performance and conformation."

Ideal Conditions for Grazing

Dolphenby Farm’s relatively flat, dry land provides ideal conditions for their grazing system. Unlike many traditional New Zealand-style grazing herds that rely on smaller cows, Dolphenby aims for larger animals weighing 550-575kg.

"Our farm is based in Cumbria but has relatively flat, dry land that's suitable for heavier cows to produce more milk," Jonny explains. "We don't need to restrict ourselves to smaller animals when our conditions can support larger cows that deliver higher production."

This approach is yielding impressive results. The herd averages 6,200 litres annually with 548kg milk solids, boasting component percentages of 4.94% butterfat and 3.88% protein.

Breeding for the Future

As calving progresses, Jonny’s attention is already turning to the upcoming breeding season. Using tools like the LIC Tracker, Dolphenby selects sires based on fertility, production, and health traits.

"We won’t compromise on feet and health," Jonny emphasizes. "No matter how good other traits might be, those fundamentals are non-negotiable."

The newest generation of calves on the farm represents genetics from Plato, Lunar Red, Waterpark Jack, and Boy, continuing the farm's strategy of thoughtful genetic selection.

Beyond Dairy: Spring Beef Calves

Beyond dairy production, Dolphenby has developed a profitable sideline in beef calf sales. Their beef calves are sired by Triple Impact EMI and Polaris (British Blue) bulls, with Lucas providing Angus genetics.

"Our beef calves sell at one month old for an average of £350," Jonny reports. "We even sold a nine-day-old calf for £300, which is a far cry from the £100-150 we used to get when we just used Herefords."

This success challenges industry perceptions about spring-calving herds. "There’s a stigma that spring-calving systems produce small beef calves," Jonny explains. "But with the right genetics, our 550kg animals are capable of producing substantial calves that sell extremely well."

Looking Ahead: Summer Grazing and Beyond

As calving winds down and grazing conditions remain favourable, Dolphenby is poised for another productive year. However, Jonny remains vigilant about grass quality and its impact on conception rates as they move into breeding season.

"We’ve had a good start to the grazing season," he says. "But every year brings its own challenges, so we’re always adapting to ensure we stay ahead."

With their balanced approach to genetics and clear management goals, Dolphenby Farm stands as an inspiring example of what can be achieved in modern dairy farming and demonstrates how a grazing operation can achieve impressive results in both production and profitability. This series will continue to follow their progress throughout the year, offering insights into each stage of their operation.

Farm Facts: Dolphenby at a Glance

• Location: Eden Valley, Cumbria
• Established: 2011
• Ownership: Tenancy farm, co-owned by Jonny Slack and one original partner
• Herd size: 550 cows
• Calving pattern: 12-week spring block
• Average production: 6,200 litres, 548kg milk solids
• Components: 4.94% butterfat, 3.88% protein
• Ideal cow weight: 550-575kg
• Genetics: Blended approach (LIC/Cogent, NZ/Ireland)
• Notable sires: Magnifico, Victor, Lion King, Plato, Lunar Red, Waterpark Jack, Boy
• Beef genetics: Triple Impact EMI and Polaris (British Blue), Lucas (Angus)