Back to News Spring turnout is one of the biggest nutritional transitions of the year for dairy herds. After months of consistent winter diets, cows are suddenly exposed to fresh grass, changing dry matter intakes, and rapidly shifting rumen conditions.
Fresh grass brings opportunity, but it also brings risks, including dips in milk yield and butterfat, disrupted rumen stability, and a loss in cow condition, just when performance matters most.
Get turnout right, and it sets up the rest of the season. Get it wrong, and performance can take weeks to recover. For farmers, merchant reps and nutritionist consultants, this is the time to focus on maintaining consistency, supporting rumen stability, and protecting energy supply.
Why Spring Turnout Can Disrupt Cow Performance
Spring grass looks excellent on paper. It is fresh, highly digestible, and often rich in sugars, but nutritionally, it behaves very differently from a winter TMR or conserved forage diet. The change is rapid, and cows do not always adapt smoothly.
Rapid diet change
Fresh spring grass is typically high in sugars and low in structural fibre. Dry matter intake can vary significantly depending on weather conditions, grazing management, and grass availability.
This creates a sudden shift in rumen fermentation patterns. Even well-managed herds can experience a temporary drop in performance while cows adapt.
Reduced effective fibre
When cows move from a controlled winter ration to fresh grass, effective fibre intake often drops. This can reduce rumination and alter rumen function, increasing the risk of milk fat depression. See data below from the Trouw Nutrition Grass Watch service which shows the average fresh grass at only 20% dry matter, with over 24% crude protein, with sugars at nearly 10% and an NDF at only 37.5%. These are significantly different to the forage quality that cows had been receiving during the winter.
Butterfat drops at turnout are common, particularly in high-yielding herds.
Energy supply becomes less predictable
Although fresh grass can be high in energy, intake can be inconsistent. Wet conditions, variable covers and grazing behaviour all influence how much cows actually consume. With a dry matter of only 20%, for cows to consume 15kg dry matter during their allocated grazing time requires them to consume 75kg of fresh grass, which during wet conditions can be a bit of a challenge.
This means energy supply can fluctuate from day to day, which makes it harder for cows to maintain peak performance.
Common Problems Seen at Spring Turnout
Many farmers recognise the same issues at turnout, even when grass quality is good. Milk yield dips are one of the most common challenges. Cows that were milking well indoors can lose litres as the rumen adjusts to fluctuating intakes.
Drops in butterfat is also widely reported, due to reduced fibre intake and rapid fermentation, which can influence milk fat production, particularly in high-producing herds. Some farms also see reduced dry matter intake as cows adjust to grazing, while others notice loose dung, reduced rumination, or inconsistent behaviour.
Body condition loss can also occur, especially where cows struggle to maintain energy intake during the transition period. These issues are rarely caused by poor grass. More often, they are simply the result of a sudden change in diet. From a mineral standpoint, farmers should watch out for symptoms of grass staggers where the supply and availability of magnesium can be impacted.
Managing the Transition to Grass Successfully
Spring turnout works best when the transition is managed gradually, and energy supply remains consistent. Where adjustments are needed, early intervention helps prevent longer-term performance losses. Introducing grass progressively allows cows to adapt more smoothly. Many farms begin with short grazing periods and build up over time.
Maintaining effective fibre intake is also important, as it helps support rumen stability and reduces the risk of milk fat depression.
Closely monitoring herd performance during the first few weeks of turnout can help identify early warning signs. Milk yield, butterfat, dung consistency, and cow behaviour all provide useful indicators.
Why Energy Balance Matters at Spring Turnout
Energy supply often becomes less predictable at turnout, even when grass quality is good. Cows are moving from a consistent winter ration to grazing, and intakes can vary from day to day depending on weather, grazing time and grass availability.
Fresh grass is often high in sugars, but that does not always mean cows receive a steady supply of energy. Rapid fermentation and changing intakes can lead to short-term imbalances, particularly in higher-yielding cows where energy demand is already high. This is often when milk yield or butterfat dips start to appear.
Maintaining a more consistent energy supply during turnout can help reduce these fluctuations. Supporting cows with a stable energy source alongside grazing can help smooth the transition and reduce the risk of performance dips.
This is particularly important in the first few weeks after turnout, when cows are still adapting to fresh grass and intakes are most variable.
The Role of Fatty Acids at Sprint Turnout
Fatty acids can help support cows through periods of dietary change by providing a consistent, concentrated energy source. During turnout, this can help maintain rumen stability, support milk yield, and protect butterfat levels.
Maintaining energy supply also helps support feed efficiency. Cows that maintain intake and performance during turnout are more likely to sustain production through the grazing season.
For merchant reps and nutritionist consultants, this is often a practical conversation with farmers. If turnout is approaching and performance is important, supporting energy supply early can help reduce risk.
Where UFAC Products Can Support Spring Turnout
UFAC offers several products that can help support cows during the transition to grass, depending on the system, performance levels, and feeding strategy.
Cholymet
Cholymet is designed to support liver function and energy metabolism, which can be particularly valuable during periods of dietary change. Spring turnout represents a metabolic shift for cows, so supporting live function during this time can help cows adapt more effectively and maintain performance.
Cholymet is often used when cows transition from winter diets, where maintaining energy balance and metabolic efficiency is important. This can be particularly relevant for high-yielding herds or cows early in lactation.
Omega Cream
Omega Cream provides a balanced fatty acid profile designed to support energy supply and milk production. Omega Cream can help maintain dietary consistency at turnout where intake and energy supply can fluctuate. This can support milk yield, butterfat, and overall cow performance during the transition period. Omega Cream can be particularly useful where farmers are looking to maintain performance while adapting to grazing.
Buta-Cup Extra
Buta-Cup Extra is a highly digestible blend of fatty acids, including C16 dats and glycerine, designed to support milk yield and butterfat production. Its palatable, free-flowing format makes it easy to incorporate into feeding systems. At spring turnout, Buta-Cup Extra can support energy supply and maintain production levels as cows adapt to fresh grass. The combination of fatty acids and glycerine supports energy intake while helping cows maintain performance during the transition.
Spring Turnout Checklist
Here are 5 key areas to look at ahead of spring turnout that often influence performance:
- Consider when cows will be turned out and how quickly grazing time will increase – gradual transitions are often easier to manage than sudden changes.
- Review fibre supply and whether cows will still receive enough effective fibre once grazing begins, as this will help support rumen stability and butterfat.
- Think about which cows are most vulnerable. High-yielding cows, fresh cows and early lactation animals often feel the impact of turnout most.
- Look back at previous years. If milk yield or butterfat dipped at turnout before, there is a good chance similar patterns could occur again.
- Finally, consider how consistent energy supply will be during the transition. Supporting cows early can help reduce performance dips and maintain production.
What Merchant Reps and Nutritionist Consultants Should Be Discussing With Farmers
Spring turnout is a good opportunity to have conversations before performance starts to change. A short discussion ahead of turnout can often prevent issues later.
Start by understanding when turnout is planned and how quickly cows will move to grass. Some farms move gradually, while others turn cows out for longer periods straight away. This can make a big difference to how smoothly cows transition.
It is also worth asking whether the farm has seen milk yield or butterfat dips at turnout in previous years. These patterns often repeat, particularly where turnout is managed in a similar way each season.
Higher-yielding herds, fresh cows and farms working to contract targets are often more sensitive to changes in energy supply. These farms may benefit most from maintaining consistency through the transition.
Discussing energy balance, maintaining dry matter intake and supporting rumen stability can help reduce the risk of performance dips. Having these conversations early gives farmers confidence and helps set the herd up for a smoother turnout.
Spring Turnout FAQs
- Why is butterfat affected at spring turnout?
Butterfat drops are often linked to a combination of reduced fibre intake, rapid changes in rumen fermentation when cows move to fresh grass and an increased intake of polyunsaturated fatty acids. Maintaining fibre levels, a consistent energy supply and improved rumen buffering can help reduce the risk. - How quickly should cows transition to grass?
Gradual transitions are generally easier to manage. Increasing grazing time slowly allows cows to adapt and helps maintain intake and performance. - Which cows are most at risk at turnout?
High-yielding cows, fresh cows and early lactation animals are often most sensitive to changes in energy supply and intake. - How long do turnout performance dips last?
This varies between herds, but dips can last several weeks if not managed early. Supporting cows during the transition can help reduce the length and severity of performance drops.
UFAC: Supporting Spring Turnout Performance
UFAC works closely with farmers, merchants, and nutritionists to support performance during key transition periods. Spring turnout is one of the most important of these.
With a focus on fatty acid nutrition, consistent energy supply and practical feeding strategies, UFAC helps support cows through dietary change while maintaining performance.
Whether supporting milk yield, butterfat, or overall efficiency, the aim is to help cows transition smoothly, protect performance, and set up the season for success.
If you’re planning spring turnout, speak to UFAC or your merchant/nutritionist to discuss the best approach for your herd.
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