Published 19.12.2025

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Dilemmas when growing grass for dry cows

Grass for dry cows should be structurally rich with a low clover content and only a limited amount of fertiliser applied, but this leads to low yields.

By Ann-Sofie K. Andreassen

Disclaimer: This article has been automatically translated for your convenience. Reasonable efforts have been made to provide an accurate translation, however, errors or inaccuracies may occur, and some content (such as images, videos, PDF-files, etc.) has not been translated.

The ideal dry cow grass helps get the cow off to a good start in lactation without milk fever. Unfertiled meadows are often suitable for dry cows as there is typically low clover content, structure-rich grasses and low potassium content in the grass. Therefore, we have investigated whether it is possible to grow dry cow grass with some of the same qualities as unfertilised meadow grass.

Several strategies for barren cow feeding

The strategy for feeding dry cows can vary and therefore there is no one grass mixture that suits all groups of dry cows.

Planned feeding and phase feeding are the feeding strategies that we have used in our trials:

With plan feeding, the farm aims to feed dry cows at a moderate energy level throughout the dry period.
Phase feeding is another feeding strategy for dry cows, where close-up cows are fed at a high energy level and acidified by adding e.g. magnesium chloride to the feed.

When choosing the grass mix, we based our choice on the fact that the grass should be suitable for flat feeding, and the mix was therefore tested on a farm with this strategy. However, we have also tested the grass mixture on two farms with phase feeding of dry cows. On one farm we tested the grass mixture for farrow off cows (3-8 weeks before calving), on the other farm for close up cows (0-3 weeks before calving).

Texture-rich grass mix without clover

Texture-rich grasses were chosen to limit the dry cows' energy intake, and clover was omitted to avoid excessive calcium levels. At the same time, the aim was to use only moderate amounts of slurry so that the potassium content - and thus the CAB value - in the grass would not be too high. As a consequence, it was expected that the yield would be relatively low.

The grass mixture Horse Max Fibre Organic from DLF was tested in the studies and, as the name suggests, is a mixture developed for horses. The composition of the mixture is shown in Table 1. On one of the farms in the trial, the grass mixture was supplemented with 3% herbal mixture.

Composition of the grass mixture Horse Max Fibre Organic - tested for dry cows:

25% tall fescue
20% meadow fescue
10% ryegrass
20% timothy
10% red fescue
15% Kentucky bluegrass

Experiences - Horse Max Fibre Organic in phase feeding

Phase feeding, where the close-up cows grazed the horse mix

On one of the farms, the close-up cows grazed the horse mix during the day and were fed a high-energy diet with acidification in the parlour. As planned, the cows only ate a limited amount of grass and there was a good grass cover in the paddock throughout the season. The grass stalled a bit in August, but recovered well.

Phase feeding where the far off cows grazed horse mix

On another farm, the father off cows grazed the horse mix around the clock. Here the energy content was surprisingly high at around 6.6 MJ/kg DM, and in theory the cows could have eaten more than they should have if grass intake had not been regulated by the grass supply. The field was divided into 3 paddocks and grass growth was poor when the cows had grazed closely and were moved to the next paddock. In August the grass stopped growing and the far off cows were moved out of the field.

Lessons learnt - Horse Max Fibre Organic with plan feeding

Flat feeding where the close-up cows grazed the horse mix

On the third farm, the far off and close up cows are fed at a moderate energy level. Here, the close-up cows grazed on the horse mix during the day and were supplemented with hay or oat vetch silage in the barn plus 1kg of grain/horse bean in late summer. The grass contained approximately 6.0 MJ/kg DM for most of the season, and provided the cows ate grass to a 100% body condition score, the close-up cows received 100-115% of the energy standard. The experience was that the cows could walk on the structure-rich grass all day without eating too much. The grass was bright and dry for a period in early summer.

Potassium and CAB values in the horse mix

The potassium content of the grass was 25-38 g/kg DM, see figure 1. For comparison, we found 13-19 g potassium/kg DM in an unfertilised meadow, while the national average for organic clover grass silage is 25-30 g potassium/kg DM (LandbrugsInfo).

Figures 1 and 2. Potassium content and CAB value for samples from horse mix grazing fields (B1, B3, B5) and meadow (B4) in 2025

The potassium content is not greatly affected by the composition of a grass mixture, but depends mainly on the application of manure and whether there is a potassium pool in the soil. The fields with horse mix were applied 20-25 tonnes of slurry in the spring. However, the potassium content decreases with the stage of crop development. Figure 3 shows the results from a demonstration where the horse mixture was harvested for silage at different times within each cut. Here, the potassium content decreased as the grass development stage increased.

Figures 3 and 4. Potassium content and CAB value for samples of horse mix before, at and after normal harvest time for the crop in question.

Potassium is included in the calculation of the CAB value, which should preferably be low for close-up cows to minimise the risk of milk fever. The horse mixture had CAB values of 200-400 meqv/kg DM, while the unfertilised meadow was around 100 meqv/kg DM for most of the summer, see figure 2. In the demonstration of horse grass for silage, the CAB value decreased with increasing crop development, see figure 4.

Grass yield was low

Based on feed controls, it is estimated that the cows utilised the fields with horse mix with 10-35 kg DM per ha per day in the period May-August. In April and September-October, daily grass utilisation was probably lower than 10-35 kg DM/ha. On two of the farms, a mowing was also carried out during the season. This means that the yield of the horse mixture was significantly lower than with regular clover grass, and only slightly higher than the unfertilised meadow.

Read more about the trial of the textured grass mixture for dry cows:
Report - Trial of structure-rich grass mixture for dry cows (pdf file, 12 pages)

Active acidification requires care

When feeding close-up cows a high feed strength ration, it is important that the cows are also properly acidified. However, this can be a challenge when grass is included in the ration. This was shown by measuring the urine pH of close-up cows in both summer and winter on three farms with phase feeding. Sometimes the pH was above 6.5, which is considered to be full acidification.

Focal points when close-up cows are fed a high feed strength ration:

analyse and select grass forage with the lowest possible CAB value for the close-up cows
be careful with the application of acidifier
follow up with urine samples

Read more about high feed strength and acidification:
Article - Organic Close-UP dry cow rations with high feed strength and acidification (pdf file, 5 pages)

Recommendations for grazing with dry cows

Far off cows are not that demanding when it comes to feeding. When choosing grass, the main thing is to make sure they don't get too much energy, but of course they should get enough. Feeding close-up cows is more demanding. Grass with low clover content and limited manure supply is recommended, see table 2.

Table 2. Grass selection for groups of dry cows

Feeding strategy	Far off (3-8 weeks of age)	Close up (0-3 weeks of age)
Planned feeding	Meadow, textured grass mix or older pasture with limited grass supply	High grass content: Meadow, structure-rich grass mix or older pasture with limited grass supply Low legume content Moderate manure application
Phase feeding	Meadow, structure-rich grass mix or older pasture with limited grass supply	Low grass content and energy-rich feed mix in the barn: Structure-rich grass mixture or older pasture Low legume proportion Moderate manure supply High grass share*: Energy-rich grass mixture Low legume content No manure application

Feeding strategy

Far off (3-8 weeks of age)

Close up (0-3 weeks of age)

Planned feeding

Meadow, textured grass mix or older pasture with limited grass supply

High grass content:

Meadow, structure-rich grass mix or older pasture with limited grass supply
Low legume content
Moderate manure application

Phase feeding

Meadow, structure-rich grass mix or older pasture with limited grass supply

Low grass content and energy-rich feed mix in the barn:

Structure-rich grass mixture or older pasture
Low legume proportion
Moderate manure supply

High grass share*:

Energy-rich grass mixture
Low legume content
No manure application

*difficult strategy in practice

When flat feeding, meadow grass or other structure-rich grasses can help regulate the grass intake of close-up cows. Alternatively, cows can go to an older pasture with limited grass supply.

When phase feeding, most people aim for a low proportion of grass and an energy-rich diet in the parlour. Here, a structure-rich grass mixture can limit the cows' grazing while maintaining a good grass supply in the field. Again, the alternative is an older pasture with limited grass cover.

High grass content for close-up cows on high feed strength and acidification is a challenge in practice. This is mainly because the relatively high CAB value often found in grass makes it difficult to sufficiently acidify the cows. However, if you can source grass with a low CAB value, either from unfertilised meadows or areas with low soil potassium, it is an option. With full acidification, the calcium level and thus the proportion of clover has little effect on the risk of milk fever, but a high proportion of legumes is still not recommended in the event that acidification fails.

Soil samples have not been taken in connection with these trials, but it is possible that current soil samples can be used to identify an area with low calcium levels that would be suitable for grass for close-up cows.

As mentioned, grass yields will be low if the grass mixture is without clover and fertiliser application is limited. You can consider compromising and still add a certain amount of legumes to the structure-rich grass mixture. It could be micro clover or another legume that doesn't take up too much space, but this idea hasn't been tested. Although the grass mixture in the trial was without clover, an increasing proportion of clover was still observed in the field. Clover seeds will very often be present in the soil on organic cattle farms.