Advanced Robot have helped us transition onto the automated milking system with impressive results. The team has a clear understanding of how the whole system needs to work, from the cow and her health right through to the robot settings. The cows are healthy and performance is terrific.
How to ensure heifers reach their genetic potential
Improved genetics are raising their for production, efficiency and health in dairy herds, But too many heifers are not reaching their genetic potential due to management limitations on farm, as British Dairying finds out.
Recent National Milk Record (NMR) data has highlighted that, when it comes to heifer rearing, there is still room for improvement. For Liz Lunn, Heifer Rearing Manager at Advanced Ruminant Nutrition (ARN), one of the key concerns is the disconnect that can sometimes exist between the performance of the milking herd and the youngstock being reared on farm.
"While many dairy herds are achieving excellent levels of performance, heifer rearing needs to achieve the same," she says. "And while we know that genetic selection sets the potential of the heifer, once those genetics have been selected, it is over to management and nutrition to determine how well that potential is realised."
With many of the herds Liz works with, nutrition is already well established and increasingly she is looking at management and environmental factors to improve productivity. "One thing is clear as we go forward from 2026, it’s not just a case of weighing calves and getting colostrum and starter feed right, it’s an integrated approach that helps to achieve success."
This is where Liz brings a different perspective, with her team approaching and viewing things differently. Working alongside not just the farm team but the vet and nutritionist looking after the milking herd, to ensure improved health and productivity, but understanding the full picture and the impact from the milking herd.
“Cow performance is continually moving forward", notes Liz. "Whether we measure it in litres of milk or kilograms of milk solids, yields are increasing, and the level of production being achieved by many herds today would have seemed almost impossible ten years ago. We are working with more and more herds achieving these levels of performance, so we also need to look ahead and think, where will we be in another ten years?”
The rearing period
Whatever the system, continuing to improve productivity and efficiency means that heifers need to keep pace with the cows they are replacing. "The target cannot simply be to produce a heifer that enters the milking herd; she needs to be capable of contributing to the next generation of herd performance.”
While significant investment has been made in many farms' management of the milking herd: from improved ventilation and lighting to greater cow comfort and more sophisticated management, the rearing period does not always receive the same level of attention, she says.
The scale of this gap can be seen in the latest NMR figures, which show the UK average 305-day milk yield as 9,136 kg, with heifers averaging 7,153 kg and second lactation cows 9,082 kg. This means that, on average, heifers are producing 78.76% of the milk produced by mature cows. For the herds ARN work with, the aim is for heifers to reach 82–85% of mature cow yield. Using 85% as a performance benchmark, heifers would ideally be achieving approximately 567 kg more than the current UK heifer average.
“If heifers are not reaching their full potential before entering the milking herd, we risk losing out on the genetic progress we have worked hard to achieve. To fully realise the genetic potential of our herds, we need to ensure that heifers are correctly grown and developed for optimal performance in their first lactation onwards,” notes Liz.
“Where nutrition and protocols are well established at the heifer-rearing stage, but heifers are still not achieving their full potential once they enter the milking herd and as mature cows, it is important to cross-reference the data with the cow-level observations we are seeing in the milking herd. An integrated, whole-team approach is essential to understand where the gap lies and identify opportunities to improve performance.”
Liz notes that once she understands what those bottlenecks are, she can work with producers to tackle the most important one first and can continually monitor progress right through to the milking herd.
“Once I have a clear understanding of the challenges the mature cows are facing, the next step is to consider whether some of these issues can be traced back to early life.
Heifer development
This is where interrogating the data and connecting it with what we see on the whole farm becomes particularly valuable.
By looking at performance, health and growth records alongside observations from the milking herd, we can start to identify whether problems may have originated during the heifer rearing stage.”
There is growing evidence that experiences during early life have important long-term consequences for a heifer’s development, health and future productivity. For example, diseases such as pneumonia and scours during the pre-weaning period negatively affect growth and have lasting effects on lifetime performance.
"Pneumonia in calves causes lesions on the lungs which are there for life and will continue to have an effect on cows particularly around stress points, such as the transition period.”
Liz believes that environmental management and facilities for youngstock are becoming increasingly important in unlocking their full potential.
“Factors such as stocking density, access to feed and water, ventilation, lying space and housing design can all influence behaviour, growth and welfare. For example, avoiding overcrowding and providing adequate cubicle availability can encourage heifers to spend more time lying and feeding, supporting healthy development and welfare.”
Ultimately, the aim is to connect the dots between the data and the observations you see as a farm team, rather than viewing the milking herd in isolation Liz suggested three key metrics that will help producers quickly work out where they are:
- % yield achieved by heifers vs. cows
- Calving age/spread
- % of heifers that reach 2ndlactation
“If we understand these three metrics, we can quantify the financial impact of improving heifer rearing. From there, we can identify the key bottlenecks, assess the investment required and, importantly, understand the potential return. Does the business need to build additional facilities, or could a retrofit provide the solution? This is often where the block occurs. If the wider business doesn’t recognise the knock-on financial impact of heifers failing to reach their genetic potential, it can be difficult to justify the investment.”
People and training
Investment doesn’t always have to be significant. Understanding the cost, break-even point and potential return on investment for each intervention helps determine which bottleneck to address first. It’s also important to look at people and management, she adds.
"Before committing to major capital expenditure, consider whether some challenges could be addressed through better training, protocols or use of the staff already on the ground. What’s clear is that an integrated approach to youngstock management is key if we are to truly make a difference to the bottom line."
〈 BACK
