Why is forage essential in organic and low-input dairying?
All farmers have an interest in feeding and nutrition of the dairy cow because the feeding expences represent the highest cost in producing a litre of milk. In addition, nutrition is a key factor in the overall performance, health, and welfare of dairy cattle.
In particular, organic and low-input farmers must be concerned about feed efficiency and nutrition, as their cattle to a large extend depend on a high use of forage.
How to secure better forage supply
- Adjust the methods for forage production
- Adopt grazing strategies for better pasture utilisation
- Broadening the inclusion of alternative feed resources and diverse swards into their system
Read more about forage in the SOLID Technical Note:
Use of diverse swards and ‘mob grazing’ for forage production
SOLID recommendations on grazing
- Use bio-diverse pastures, e.g. grass-clover. They are sufficiently productive to serve as a viable alternative to conventional pastures as they can maintain animal productivity at high levels.
- Grazing duration should be more than 30 days. Less is in general too short to allow for an adequate recovery of the pasture and can result in low intakes.
- Grazing rotation should be long enough to allow for full recovery of the pasture while the residual ungrazed forage should be left relatively tall.
- Use high stocking rotational grazing of bio-diverse pastures, as this has remarkable effect on the build-up of the soil organic matter and is recommended for soil improvement.
Benefits of diverse swards
Utilizing diverse swards can potentially result in a number of benefits. Most important are higher productivity and greater stability of biomass production compared to monocultures. The diverse swards are also more resilient to adverse weather, climate and management conditions. In addition, forage from diverse swards contain amounts of minerals per kg DM of grazed forage.
However some farmers experience difficulties in establishing and maintaining herbs in a diverse ley. In that case, herb strips may be a solution.
Benefits of mixing species
- Diverse mixtures have increased above-ground biomass production and crop cover than monocultures
- Productivity increases over time
- Greater stability of biomass production
- Improve soil organic matter
- Mixing species with different properties allows better weed control
- Greater resilience to variable weather, climate and management conditions
- Inclusion of species with slower N release can result in lower N losses
- Better N utilisation; lower costs for N fertilization
- Cover crops increase infiltration
- Diverse mixture support more pollinators throughout the season
- Diverse mixtures provide a larger food range for other invertebrates (“bird food”)
- Mixtures with higher diversity do not compromise wild plant diversity
- Slower decomposing species would decrease the risk of nitrogen losses to the environment (leaching, gaseous losses)
How to design the right mixture
- Mixes with high agronomic productivity function contain both lucerne and white clover while the overall performance improves by including a third or fourth legume species
- Multifunctional mixtures that contain black medic, lucerne and red clover have the best performance and resilience
- Some species such as meadow pea, winter vetch and large birdsfoot trefoil often show low performance in northern European climates – but can perform better under other climatic conditions
- Sainfoin shows marked differences in performance depending on region and soil. It is attractive as a non-bloating legume, but does not survive well in competition from grasses.
- White clover and red clover have better N utilisation than black medic or lucerne. White clover consistently performs well in terms of yield and persistence and its creeping habit makes it the best legume adapted to grazing. Red clover is generally more productive than white clover, but, less persistent and less tolerant to high grazing pressure
- Lucerne is a high yielding species and produces high quality feed, when dried or ensiled, although it is not commonly grazed. Lucerne can be relatively intolerant to being cut short, suggesting intolerance to grazing
- Ryegrass is recommended for high yield while festulolium provides a combination of high quality forage with good winter hardiness, persistence and stress tolerance
- Sweet clover performs best when inoculated with rhizobium bacteria. Yet it is increasing the risk of bloat.
Diverse swards tested on SOLID case farms
In a case-study on a British farm involved with SOLID, herbage yield, composition and nutritional value of diverse swards were assessed on a monthly basis from May to September( 2014) and compared with those of grass-clover.
The diverse sward mixture included 10 different grass species, 6 legumes and 5 herbs. This study showed that although pasture productivity of the diverse sward was lower than that of the grass-clover lay, the total productivity remained relatively high, more than 10 tonnes per ha. So, diverse pastures can, according to this study, serve as a viable alternative to conventional pastures.
Grazing Strategies for increasing Soil Organic Matter
The way sward is managed and the composition of species in the sward can influence the build-up of soil organic matter.
Farmers are interested in increasing soil organic matter because og a number of benefits.
Soil organic matter can:
- serve as a reservoir of nutrients for crops
- provide soil aggregation
- increase nutrient exchange
- retain moisture
- reduce compaction
- reduce surface crusting
- increase water infiltration into soil
Case study: Mob grazing on dairy farms
Mob grazing is a grazing system characterised by high stocking densities of livestock which are moved frequently from paddock to paddock with the aid of electric fences, trampling forage into the soil as they graze.The pasture land is then left ungrazed until it is fully recovered, allowing the whole host of plant species to establish in the sward.
Mob grazing has been considered to benefit the soil organic matter by leaving higher residuals in the paddock. However, the claimed benefits of mob grazing on soil organic matter and animal performance have not yet been studied in scientifically robust studies.
Rob Richmond, a UK organic dairy farmer in the Cotwolds, has been working with diverse swards and mob grazing over seven years. The approach was developed by Alan Savory in Southern Africa. When Alan Savory was visiting the UK, the Organic Research Center, UK took the opportunity to invite him and farmers of a dairy discussion group to take a look at the farm.