Drought Forage Management
Despite small amounts of much needed rainfall in recent days, the extent of the dry spell is still having a toll on most farms. Grass growth rates are still far below normal for this time of year, meaning that grass supply remains well behind demand. The challenge for the short term will be to stretch out grass supplies whilst maintaining dry matter intakes (DMI) and fulfilling nutrient requirements using alternative feeds. By achieving necessary dry matter intakes and meeting nutritional requirements, there should not be a disproportionate reduction in milk yield. If DMI requirements are not met, then excessive drops in milk production at this time of year will have a negative effect on milk output for the remainder of the lactation.
There are a lot of differences in grass availability from farm to farm and each will need to adopt a different strategy based on the farm scenario. Below are a number of feeding options for a typical dairy herd with a dry matter intake of 16 - 18kg/cow.
Scenario One: 10 Days Grass Remaining
In this case, there are approximately 10 days of grass remaining on this farm. To conserve supplies, demand on grass needs to be reduced immediately by introducing supplementary feeding i.e. increasing feeding levels of concentrates, introducing grass silage or a combination of both. Two typical diets for this scenario are as follows:
|5kg fresh grass
5kg grass silage
8kg 15% Summer Dairy Nuts
|6kg fresh grass
6kg grass silage
6kg 16% Dairy Nuts
Scenario Two: 5 Days Grass Remaining
If not already, concentrate feeding rates should be increased to 8kg/cow/day in the parlour. If feeding above this level, you need to consider introducing a midday feed to minimize digestive upsets. This will allow the total concentrate inclusion in the diet to increase to 10 kg. The Drinagh Summer Buffer Mix is designed to meet these needs. Silage must also be offered to meet forage requirements. A typical diet is:
6kg 15% Summer Dairy Nuts (3kg am & pm)
4kg Summer Buffer Mix (midday feed)
4kg fresh grass
4kg grass silage
Scenario Three: Graze Second Cut Silage
Where grass availability is limited but the possibility of grazing a portion of second cut silage is still an option. This option depends on the stage of growth of the crop. Use a strip wire with a back fence to increase grazing efficiency and to protect regrowth. However, if this grass has gone beyond a certain stage of growth, utilization will be compromised, and grass will be wasted. If grass has gone too strong you should proceed to cutting for bales/pit silage as originally intended. If you decide to graze second cut silage, concentrate feeding level should be maintained in order to make grass last as long as possible. If you choose to harvest second cut silage and there are doubts over the nitrogen levels prior to cutting, Drinagh Advisory Services can test for grass sugars and nitrates.
Scenario Four: Grass Silage as Only Forage Source
When grazing grass is no longer an option, cows will have to go on a full-time grass silage and concentrates diet. It is hugely important to note that a cow’s overall diet should contain a protein concentration of 16% so an appropriate concentrate should be fed when balancing silage. The 17% High Maize Nut is a suitable feed to use here. A typical diet in this scenario would be:
6kg 17% High Maize Nut
4kg Drinagh Buffer Mix
8kg grass silage*
8kg of dry matter/cow/day
*no need to offer more than 8kg dry matter of silage to cows when supplementing correctly.
Winter Feeding Options
The starting point for any winter feed budget is to have at least 50% of the forage required for the winter period. Once you have 50% of your forage requirement you have options.
What to do?
Complete a winter forage budget now (if short you may get better value for your money by buying now rather than in 3 or 4 months’ time). If you predict you will be short on fodder – actively source fodder now.
However, avoid panic buying feeds and consider the following factors:
- What is the nutritional value of the feed?
- What is the cost of the feed relative to other feeds? i.e. cost per kg dry matter.
- Is there adequate storage, handling and feed out facilities for this feed?
- Is a home-grown forage such as third cut silage, redstart/forage rape still an option?
|Product||Description||Nutritive Value||Cost per kg DM|
|Baled Silage||€35 Round bale delivered (25% DM)||Good - Average||€0.19|
|Hay||€45 Round bale delivered (85% DM)||Good - Average||€0.21|
|Maize Silage||€1500 ton/pitted (6.5 tonnes DM yield/acre)||Good||€0.23|
|Drinagh Buffer Mix||€225/ ton delivered (88% DM)||Good - Average||€0.26|
|Straw||€33 round (85%DM)||Poor||€0.26|
|Lucerne/Alfalfa Pellets||€235/ton full load delivered (88% DM)||Good - Average||€0.27|
|Fodder Beet||€55/ton washed + delivered (18% DM)||Good||€0.31|
*Comparable costs of feeds on DM basis.
Grass 10 Messages
- Farms suffering from drought: Where growth has stopped and where fertiliser has been applied with no breakdown, nitrogen spreading should cease.
- Heavy soils still growing grass: Nitrogen should still be spread on farms that are still growing grass to maximise growth rates. Any fertiliser being spread should include sulphur.
Fertilizer for a third Cut:
The option may be available for a third cut of silage on some farms. Target with 2000 gallons of slurry and 40 - 60 units of Nitrogen. If growth recovers the extra ground saved for silage will help boost feed reserves however if growth remains slow the option will also be available to graze this ground in September.
*If applying fertilizer, it is best to apply late in the evening or with some precipitation forecast.
Key Drought Messages for Future Plant Growth:
- In a drought, spring tillers die, and the remaining tillers are stressed. The period following drought is critical to allow autumn tillering to occur, otherwise pastures will thin out over autumn, production will be poor, and weeds will invade.
- Plants that are still alive but growing slowly due to lack of moisture can quickly recover, green up, and be back into production.
- Dormant plants where above-ground parts have died back, but buds at ground level are surviving, can begin tillering from these buds when rain falls. New green shoots can be seen in the base of dead pasture within 1-2 weeks after rainfall, but recovery in terms of pasture growth rates will still be some weeks away.
- Grass that that looks dead now (although of reasonable quality) will be lost to decay once the rain returns; therefore needs to be utilised now.