Key advice on feeding in summer drought conditions
Here's key advice from Teagasc on how to manage drought conditions on your farm
Soil moisture and high daily temperatures have begun to strongly impact on daily grass growth nationally, with growth rates on many farms falling below 45kg DM per day.
As a result, average farm covers are beginning to drop below the target 160-170kg DM per cow. Given the prospect of sustained dry weather, it is important that prompt actions are taken to manage the situation.
Hints and tips on feeding out forage supplements in dry weather
Dry field conditions should make the task of feeding out much easier compared to spring. Each farm will have its own preference (based on facilities/machinery/labour) but the main objective remains to reduce total daily grass intake to the level of daily growth or below.
Feeding forage will be necessary for many farms. Once the available daily grass is known, some options for feeding are:
- Separate a proportion of the herd and place on 100% silage plus meal in a convenient paddock. This may be a paddock marked for reseeding later in the year. A small area of fresh grass can be allocated to this group daily. Some farms have used a double temporary wire feeding rail to good effect. This approach simplifies grazing management of the main group.
- Offer silage to all cows in the grazing paddock, placing silage along perimeter fencing. This works best where feed can be allocated with a diet feeder. Total silage allocation should be calculated to balance available grass on the paddock daily. Forage should be spread along a long linear distance (1m per cow) to reduce competition and bullying.
- Hold a proportion of the herd in the yard for silage feeding after milking. These can be turned out with the main group after 3-4 hours feeding. This simplifies feeding out silage but in dry conditions there is a risk of injury due to slippery concrete floors
- High fibre straights can be offered PKE/hulls/pulp at a rate of 3-4 kg per cow. Some farms choose to feed these in mobile feed troughs in the field. Note that citrus pulp does not work well in this situation due to its lower NDF fibre content. Ensure full access to clean water.
- Whichever actions is chosen, it is vital act now to ensure that grass supply is stretched out as early as possible. If covers are allowed to drop too quickly, it will result in the entire herd having to managed on silage for a period. Grass recovery will also be delayed.
- Plan supplement until 4-5 days after growth exceeds demand. Assess feed plans with this in mind.
Grazing management decision rules
- The main priority now is to reduce daily grass demand to below daily growth rate. This will help to hold grass cover on the farm, protecting current growth and speeding up recovery when rain arrives.
- Rotation length must be maintained at 25-27 days approximately. Effectively this means grazing no more than 4% of the grazing platform daily. Assess the grass available on this area and supplement with forage/concentrate to balance herd demand
- For example, a 140 cow herd is grazing 45ha (3.1 stocking rate). Max daily area allowed should be 1.8ha (4% of 45). If there is 1100kg DM per ha available then the paddock has 1.8*1100= 1980kg available. Herd demand is 2520kg per day, therefore 540kg of total supplement is required per day.
- In this example, holding total grass allowance to 1980kg equates to 44kg daily demand per ha day (1980/45). This will hold grass cover per ha reasonably well if growth rates are within 5-7kg daily. Larger deficits will rapidly reduce average farm cover.
- If there is larger deficit between growth and demand it will be necessary to temporarily reduce demand further by reducing grazing stocking rate and feeding extra silage.
- Increasing rotation length beyond 30 days may lead to much reduced grass quality in current conditions.
- Post grazing residuals of 4 to 4.5cm must be maintained , otherwise feed is being wasted
- Maintain fertilizer N at 25kg per ha after grazing. Risk of losses are low with CAN products. however if drought conditions persist to >60mm soil moisture deficit it is advised delay N until rain is forecast.