Zero grazing has fallen in and out of fashion many times over the decades. However, as farms have expanded and equipment choice has improved, Hefin Richards, an independent nutritionist from Rumenation Nutrition Consultancy, believes we could see a resurgence in the popularity of zero grazing.
“In the past, it was generally used on farms where field layout made grazing difficult, or where land base was limited, and maximum utilisation was the aim. However, there are growing opportunities for zero grazing as climate conditions change.
“Zero grazing could help farmers avoid making silage on off-lying land and instead feed fresh grass to fill in shortfalls on the grazing platform.
“It also allows producers to introduce grass into the diet whilst cows are still housed, especially when grass is short, or ground conditions are challenging early in the season.”, Mr Richard explains.
Furthermore, replacing late-cut silage of zero grazed grass could significantly reduce costs and enable better utilisation of autumn grass.
Below, he examines the pros and cons of zero grazing and gives practical advice on implementation.
What is zero grazing?
Zero grazing, also known as ‘cut and carry’, involves cutting fresh grass daily and feeding it to housed dairy cows (although it could be used for beef cattle or growing stock). This is one of several grazing systems used by grassland farmers.
Zero grazing advantages:
- Maximum grass utilisation: Prevents losses due to rejection, soiling and trampling.
- Efficient use of remote fields: Ideal for fields too distant or dissected by roads.
- Better use of grass during shoulders of the season: Less soil damage compared to grazing in wet weather because of low ground pressure tyres versus hooves.
- Consistent feed quality: You can deliver a consistently high-quality product to cows without the weather negatively impacting grass intake.
- Potential for higher grass intake: Cleaner cuts reduce contamination from dung and urine.
- Wider use of grass leys within arable rotations: Eliminates the need for investment in infrastructure such as roadways, fencing and water provision.
- Cost savings: Replaces expensive Total Mixed Ration (TMR) with high-quality grass for housed cows, especially beneficial during mid/late lactation when consistency is less critical.
- Can be adopted by a range of production systems: For example, a high-yielding, housed dairy could replace a proportion of TMR for 6-8-months, reducing silage, concentrate use and protein requirements. Alternatively, a ryegrass catch crop after maize could be cut and fed as soon as ground conditions allow, gradually releasing land for slurry application pre-cultivation.
- Minimises protein and dry matter losses compared to silage harvesting: Losses from field to clamp can rise to more than 20% with early and late season silage.
Zero grazing disadvantages:
- Higher equipment and operation costs: More expensive than traditional grazing.
- Labour-intensive: Requires significant labour for large herds.
- High-grass diets: Can result in low dry matter slurry and dirty cows.
- Machinery dependence: Breakdowns can severely impact operations.
- Contract restrictions: Not suitable for milk contracts requiring outdoor grazing.
- Practical challenges: May not fit all farm layouts, requires wide passages and feed barriers for efficient operations.
Potential cost savings versus costs
Replacing TMR with 11kg DM of zero-grazing grass for the mid/late lactation group of cows can result in significant savings.
For example, if zero grazing displaces silage and blend in TMR, this is a saving of £1/day. Based on feeding 200 cows for 180 days, you would save £36,000 (see table 1).
| Ration 1 | Ration 2 | |
| Silage second cut @£35/t | 38kg a head at £1.33 | 10kg a head at 35p |
| Zero grazing @£15/t | 0kg | 65kg at £1 |
| Maize silage @£45/t | 10kg a head at 45p | 10kg at 45p |
| Sodawheat @£200/t | 5kg at £1.01 | 5kg at £1.01 |
| Dairy minerals @£600/t | 0.100 at 6p | 0.100 at 6p |
| Blend @£326/t | 5kg at £1.63 | 1.75kg at 57p |
| Total | £4.47 | £3.46 |
| NUTRIENT ANALYSIS | ||
| DMI (KG) | 23.4 | 22.3 |
| Dry matter (%) | 40.2 | 24.3 |
| ME (MJ) | 270 | 270 |
| Energy (MJ kg DM) | 11.5 | 12.1 |
| CP (%DM) | 17.4 | 17.5 |
| Sugar (%DM) | 4.17 | 9.12 |
| Total starch (%DM) | 18.9 | 16.4 |
| Starch & sugar (% DM) | 23.1 | 25.5 |
*If 200 cows are fed 11kg DM daily, 2t DM of fresh grass would need to be harvested daily. Based on it costing £30/t of DM to harvest and deliver grass, this will cost £60/day (2x30). At £60/day to harvest plus £30/t for grass this equals £90/t in total (the equivalent of £15 freshweight if grass is 17% DM (90X17).
*Ingredients are included on a freshweight basis.
Costs of zero grazing will vary greatly depending on new versus used equipment, utilisation of existing tractor/labour and distance from fields to dairy.
Grazing can be a cost-effective option, but logistics may prevent this. It also requires strong management skills to maintain sward quality and grass intake. Whereas, mowing a set area allows for complete regrowth and some farmers will find zero grazing easier to manage.
Allocation
Weight is of limited use since surface moisture and daily dry matter variation will lead to vastly varying fresh weight required to meet dry matter intake target.
Some farmers use plate meters to estimate covers, similar to grazing, and then cut a set area based on GPS. This logical approach adds precision to the process.
For example, to harvest 2,000kg of DM, with grass covers at 2,800kg and a target residual cover post-mowing of 1,200kg, the aim would be to harvest (2000/1600 = 1.25ha). This can be measured using tractor GPS or mobile phone software.
Feed out
Feeding grass separately from other ingredients reduces the risk of overprocessing and wastage. Incorporating it into a TMR can be challenging due to DM variation can make accurate allocation difficult, leading to the wastage of all materials in the mix.
Some farmers do feed low inclusions of fresh grass within a mix, but the best practice is to feed it as a separate meal to TMR.
Time of cutting
Cutting grass in the morning may fit better with the labour schedule, especially on weekends and provides more time for repair in case of breakdowns.
Meanwhile, cutting grass in the afternoon increases dry matter and sugar content. This allows for grass to be eaten overnight, with TMR fed in the morning or cows grazed during the day.
Preference will largely depend on staffing and your end goal.
Choosing grass leys
When sowing specifically for zero grazing, choose a mixture that will provide a reliable yield under an intensive cutting regime (20-25 days).
Paul Morgan, Germinal GB Area Sales Manager, recommends using Aber HSG 2 Multi-Cut, a specialist, high-sugar silage grass seed mixture designed for regular cutting.
Aber HSG 2 Multi-Cut is an ideal choice for producing high-quality silage due to its ability to maintain exceptional yield and quality through multiple cuts, while also providing excellent ground cover and enhanced silage fermentation.
Expert advice on zero grazing
Our grassland experts are here to help you. Contact us for advice on implementing zero grazing practices effectively.