With turnout a pivotal point in the year for any grazing cattle, here’s what you need to know about supporting digestion, stimulating growth rates, and sustaining milk production.
It takes 3 weeks for the rumen to adjust to any dietary change – such as the radical transition from feeding cattle a winter forage to grazing cattle on spring grass. Grass should be monitored from as soon as late winter, meaning it’s not too soon to be thinking about turnout!
When managed properly, lush spring grass is the foundation for cost-effectively sustaining strong milk production and optimal cattle weight gain on grass. When managed badly, the transition to turnout might expose grazing cattle to the risk of challenges like butterfat drops, growth checks, and cattle staggers – to name a few.
In today’s challenging climate, even the smallest turnout error is unaffordable. Here’s some helpful advice from our supplementation specialists this next grazing season.
Keep Tabs On The Status Of Your Grass
You’ll have likely heard this preached many times before – but not without good reason. Homegrown forage is the most valuable natural resource to any grazing system.
Close monitoring and forward planning will help to ensure nutritional needs are always met without waste. There are two key aspects to grass monitoring — quantity and quality.
Grass Quantity
Grass growth rates can change so quickly and radially with the weather. Offering the right amount of grazing grass at all times requires regular measuring and adjustment. It’s great practice to use a sward stick on a weekly basis to calculate kilograms of dry matter per hectare, and plan your grazing accordingly to efficiently meet the needs of your livestock:
| Cattle stage | Allocation (% of body weight) |
| Early to mid-lactation cows | 2.5 |
| Late-lactation cows | 2.0 |
| Dry cows | 1.5 |
| Heifer replacements | 2.5 |
| Calves up to weaning | 3.0 |
| Weaned calves | 2.5 |
| Growing & finishing cattle (100–200kg) | 3.0 |
| Growing & finishing cattle (300–600kg) | 2.5 |
Grass Quality
It is critical to understand the factors that impact on grass ‘quality’ – i.e. how valuable it is to the grazing animal. Grass quality can be defined through the following intrinsically linked factors tested for within a nutritional analysis:
| Definition | Grazing challenges | |
| Dry matter
(DM%) |
The proportion of fibres, proteins, ash, water-soluble carbohydrates, and lipids – after water has been removed. | Dry matter is crucial for rumen health and function. DM is typically insufficient in spring grass (15%), especially after rain. This can cause dietary upset like acidosis. |
| Digestibility
(D-Value) |
A measure of digestibility. | D-value is highest in spring in young swards. When seed heads start to emerge – as early as May – grass digestibility can reduce to levels as low as 67%. |
| Energy
(MJ/kg DM) |
Energy that cattle can derive from feed. | Spring grass is as good a feed as you can get – making use of it is the challenge! |
| Crude protein
(CP %) |
A measure of protein content (but not protein quality), typically impacted by fertilising. | Dietary crude protein concentrations can be as low as 12-14% DM without any detriment to productivity. |
| Water-soluble carbohydrates | The soluble sugars that are quickly released in the rumen. | During the spring, the dry matter of fresh grass can vary significantly on a day-to-day basis!!! |
| Minerals | Nutrients critical to digestive, reproductive and immune functions. | Spring grass is often lacking magnesium leaving cattle prone to grass staggers. |
IMPORTANT! Whilst spring grass is typically very high in energy, it is often low in dry matter. Adding to this, water-soluble carbohydrates (sugar) levels fluctuate, not least in the spring. This is far from what the rumen favours, and poses a challenge to health and productivity as well as the all-important feed efficiency. That’s why it is so important to balance grazing cattle with a consistent supply of dry matter and sugar.
Keep Grazing Cattle In Balance
We’ve established the reason behind the importance of balancing high-energy grass with consistent levels of dry matter and sugar in maintaining health and performance this turnout. You’re now likely wondering which is the best way to accomplish this balance and keep the rumen pH at an optimal level (6.0) when grazing lush spring grass. Here’s the 3 main options:
- Buffer feeding with a fibrous ration at regular intervals
- An in-parlour feed that includes a rumen conditioner/buffer/yeast
- Offering a mineral block or feed lick within the grazing paddock
All options are efficient at balancing the grazing in their own way and all come with their own pro’s and con’s.
Buffer feeding offers an opportunity to be super precise with formulation and can make use of remaining homegrown forage from the previous season. When fibrous matter is cut to the correct length, it also helps to stall the flow of high energy grass through the digestive tract. However, buffer feeding depends on the grazing cattle still having appetite for it (it’s like putting sweeties and vegetables in front of a child and expecting them to choose the vegetables).
In-parlour feeding offers a level of tailoring in its formula and quantity per cow based on her needs. When formulated with a rumen conditioner/buffer/yeast, the rumen microbes (bugs) are fed and multiply at a greater rate required for digesting the grass. However, this is not a continual supply and can cause peaks and troughs in rumen pH.
Mineral blocks offer an opportunity to cost-effectively target grazing cattle with specific essential minerals, vitamins and trace elements often deficient in grass – especially when fast growing. Additionally, when conditions are wet, cows are more likely to splash the grass with soil and ingest antagonists which can exasperate the issue. Some mineral blocks include buffers and live yeasts to help prevent the build-up of acidosis-causing lactic acid. While mineral blocks can enhance saliva production and therefore regulate rumen pH, they don’t tend include sufficient sugar to balance grass throughout the grazing period.
Feed licks (when molasses-based and unlike a mineral block) offers a consistent supply of sugar required to feed the rumen microbes – increasing rumen turnover, and consequently, dry matter intake. Importantly a feed lick is also quick and easy to supply, freeing up time for field work. However, a feed lick alone does not supply the physical dry matter – it must be used in conjunction with grass or forage.
Keep Grazing Cattle Efficient With A Feed Lick
If a feed lick sounds like a suitable option for your system, it is now important to establish which feed lick is going to do the best job most cost effectively.
Crystalyx Cattle Booster is designed with that as a principal concern, and is research-proven to increase digestion by 10% and dry matter intake by 15%. Manufactured using a unique manufacturing process, Crystalyx boasts an array advantages:
- Dense in energy – Meets energy needs 24-7 with intakes of just 100-150g/day in growing cattle and 150-250g/day in lactating cattle.
- High in sugar – 38% sugar to support digestion and grass/forage throughput/utilisation.
- Low in moisture – Reduces the risk of gorging or breaking up in poor weather (2-3% moisture, other blocks can contain in excess of 20%).
- Highly palatable – Attracts cow visits, even on the lushest of grass.
- Cost effective – Lasts up to 3X longer than other feed licks.
- Consistent in quality – Manufactured using a unique cooking process to ensure consistency.
- Research-proven:
- Increased digestion by 10%
- Increased DLWG by up to 36%
- Increased pregnancy rates by 15%
- Increased bull fertility by 24%
Keep An Eye Grass Staggers!
Rapidly growing spring grass typically has a low magnesium content (0.1-0.2% in dry matter). Due to its low dry matter and quick passage through the rumen, magnesium absorption into the animal’s bloodstream can be significantly reduced.
While clinical grass staggers (hypomagnesemia / grass tetany) is relatively unlikely in grazing cattle, subclinical magnesium deficiency cases are thought to be much higher. Subclinical magnesium deficiency often goes undetected, but the impact on performance cannot be ignored.
So don’t wait out for the clinical signs – be sure your grazing cattle have adequate magnesium provisions in their diet to know that magnesium is not a performance limiting factor.
Research at Glasgow University (School of Veterinary Medicine) has confirmed that the high digestibility and availability of the magnesium sources used in Crystalyx Cattle High-Mag ensures that normal blood magnesium levels are maintained when target intakes are achieved.
Bigger Picture
We’ve had the lens on nutritional balancing at turnout. But turnout is helped or hindered by many different management factors. Here’s some reminders:
- Avoid using potash fertilisers to reduce risk of grass staggers
- Ensure your parasite control and vaccinations are up to date
- Be prepared for challenging conditions (i.e. another wet season)
- If seeking early turnout, first utilise south-facing autumn-rested fields
- Transition onto grass gradually, gradually increasing grazing times
- Target spring grazing heights of 3.5 – 4 cm during the first grazing rotation
- Take care of the flies early before they strike and cause stress
- Use the AHDB feed and forage calculator to forecast forage requirements
Keep Yourself Ahead!
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