MMN January 2025 – What to Use if Draff is Unavailable

Draff has become an important feed source within the dairy industry over the years, providing a good source of digestible energy and protein. The typical crude protein content of draff on a dry matter basis is between 16.0-22.0% and it has a metabolisable energy (ME) content of between 11.0-11.7MJ/kg DM. Draff is a highly palatable, moist feed which can be fed in large quantities (typically 8-10kg per head for milking cows) and is a relatively low-cost feed at between £40-£50 per tonne depending on distance from the distillery. The type of energy source provided by draff is high digestible fibre and it is low in starch, which reduces the risk of acidosis in the rumen.

Draff availability is not always guaranteed throughout the winter months due to a variety of reasons, including a higher demand for anaerobic digestors. Therefore, draff may be unavailable and you may need to consider alternative ingredients to supply those energy and protein levels within the ration. Determining the best alternatives will depend on availability of the products being delivered to your area and price per tonne, as well as their nutritional value and recommended inclusion rate. Alternatives that could be considered to replace the draff element of the diet include, but are not restricted to, brewers grains (or other moist distillery co-products e.g. Vitagold), distillers dark grains or soya hulls.

Brewers grains is another palatable, moist feed which is a co-product from the brewing industry. Like draff, it has a high crude protein content of 20.0-26.0% and an ME content of 11.7 MJ/kg DM. Brewers grains can be fed in similar quantities so if draff is unavailable, brewers grains can be fed like for like in the ration.

Table 1. Nutritive value of draff on a dry matter basis and alternative options.

Distillers dark grains are another palatable, dry feed which are high in protein and energy, and can be in pellet or meal form. Typically, they have protein levels of 28.0-34.0% and an ME typically between 13.5-14.0 MJ/kg DM which is higher than draff, and with the higher dry matter of around 90%, quantity fed per head is lower (typically 2-3 kg per head for milking cows). Distillers dark grains come in two types, maize or wheat. A portion of the protein is rumen undegradable protein which by-passes through the rumen into the small intestine to be digested. Due to their palatable nature, distillers dark grains can stimulate intakes of less palatable feed and improve milk yields. Products from the distillery industry tend to contain yeast fractions which stimulate rumen activity, promote fibre digestion and overall feed efficiency.

Soya hulls are very palatable and typically used to bulk up a ration. They are reasonable in ME at approximately 11.8 MJ/kg DM. This energy source is rich in digestible fibre which assists in maintaining rumen pH and reducing the risk of acidosis. In contrast to draff and other distillery co-products, soya hulls have a lower protein content of 11.7%. Therefore, soya hulls would need to be fed alongside a protein rich feed like rapeseed meal (crude protein content of 37.5%) and it is a good source of undegradable protein that will by-pass the rumen during digestion.

Any changes to the diet should be discussed with your nutritionist to ensure that the alternatives for draff are providing the same quantity and quality of protein and energy sources to minimise the impact on milking performance.

cara.campbell@sac.co.uk; 01586 552502