Navigate your way through winter 2015-16

Published 20 November 15

There is no hiding from the fact that the winter of 2105-16 is going to be challenging for many dairy farmers. However, paying close attention to the details of nutrition can help reduce some winter feed costs, according to Dr Stephen Whelan, R&D Manager at AHDB Dairy.

Step 1. Do a budget

The amount of forage on the farm can be estimated by measuring the volume (m3) of the clamp and knowing the approximate density of the forage (Table 1). Knowing how much feed is in the store will allow for planning of purchased feed and turnout date in the spring.

Table 1. Densities of silages at various dry matter content


Density (kg/m3)


Grass Silage

Maize Silage

Whole Crop Wheat

200g DM/kg




250g DM/kg




300g DM/kg




350g DM/kg




400g DM/kg





Step 2. Assess the quality of the feed in stock

Clamped forages are a variable feed. This means that the silage which will be fed in three month time will be quite different to the silage that is being fed today, even if it is from the same clamp. To overcome this, it is recommended that the forage is analysed on a monthly basis. This analysis can then be used to more accurately meet the requirements of your animals ensuring nutrients are neither undersupplied nor wasted. For example, conducting a mineral analysis will help identify any potential copper antagonists in the forage. For more on how to sample forage clamps, see ‘The 5Ws and 1H of silage sampling’.

Step 3. Assess the requirements of your animals

Regular forage analysis allows for part of the supply side of the feed budget to be calculated. The demand side of the equation can be calculated based on the number of animals and their individual requirements. Some forage analysis will provide an estimate of intake potential expressed as g/kg ML or g/kg0.75 (Figure 1). Where this is provided, intake potential can be quickly estimated. For example, in Figure 1 the intake potential is 104g/ kg ML). For a 650kg cow we can work out the intake as weight0.75 x intake potential ÷ 1000 = 6500.75 x 104 ÷ 1000 = 13.4kg DM/ day.

Intake of specific nutrients like CP is also very important. But there may be room to reduce the overall content in the diet. In a recent AHDB Dairy funded trial, researchers at Harper Adams and Nottingham Universities found that diet CP could be reduced to 14% without impacting on production or health. Importantly, the 15% CP diet was £0.29 cheaper than the 18% CP diet.

 Graph 1


Figure 1. Fermentation characteristics of grass silage with intake potential highlighted in red

Lastly, it may be worthwhile examining the mineral usage on the farm. In another AHDB Dairy-funded study, researchers from Harper Adams University highlighted that most farms were over supplementing their animals with minerals. Giving one person responsibility for the mineral nutrition on the farm will help reduce the risk of double or even triple supplementing animals with minerals and help reduce the feed bill.

Step 4. Explore alternative feed options

Ultimately, the dairy cow needs energy and amino acids to make milk, but the flexibility of the rumen means that the type of energy and protein supplied to the animal is of lesser importance. This flexibility means that farmers can choose from a wide variety of feed stocks, but it is important to know which ones represent the best value. To help identify which feeds represent the best value for money, AHDB has developed the Relative Feed Value Calculator.

Including fresh pasture, either through an earlier turnout in spring or through the use of cut and carry technology, may also help reduce feed costs on the farm. Work funded by AHDB Dairy at SRUC suggests that including 50% pasture in the diet of dairy cows can significantly improve the economic surplus per cow (Figure 2).

 Graph 2

Figure 2. Economic surplus per cow under a range of milk price scenarios

Step 5. Reduce feed waste

International data suggest that up to 6% of concentrate and 20% of forage feed are wasted each year. This adds significantly to the cost of dairy farming and also reduces the efficiency of feed conversion into milk on the farm. Recently, AHDB Dairy produced a short video that will help farmers identify where reductions in feed waste can be made.