Farmers looking to feed more concentrates this winter in a bid to extend dwindling forage supplies will need to pay close attention to ration balance to maximise return on investment.

With reduced forage stocks on many farms as a result of the summer drought, supplies are expected to be at down at least 10% and, and as a result, some winter dairy diets could dip below the usual 40% minimum forage inclusion rate, as farmers look to bridge the gap with concentrates.

According to Dr Chris Bartram, head of nutrition with Mole Valley Farmers, dropping below this figure could see milk production and milk fats taking a hit, unless rations are carefully balanced.

Speaking at the The UK Dairy Day at Telford, on Wednesday, he said that with a forecasted milk price of more than 30ppl and despite inevitable feed price increases, the milk price to feed price ratio is likely to hold at around 1.3, which is the highest it has been in recent years. At this level, he said farmers can expect to see a good return on investment from feed, as feeding an extra 1kg of concentrate a day, in general, reduces forage intakes by 4kg a day.

The fact a greater proportion of the diet could be made up of concentrates means that the protein content in the extra concentrate may need to be reduced too. This will avoid excess feeding, which may be detrimental to the cow and will add unnecessary cost to the system.

Dr Bartram also highlighted the starch content of the concentrate has to be considered as over-feeding a high starch feed could compromise rumen health and lead to depressed milk fats – an increasingly important parameter for many milk cheques.

He pointed out there are some general rules that should be applied when rationing to promote milk fats (see table) and avoiding providing too much rapidly fermentable carbohydrate (RFC), which tends to be high in cereals, is one.

“If you want to feed starch for milk protein, consider including a range of cereals or a higher level of maize grain.”

At the same time, compound mineral levels need to be considered and specifically copper.

“If you over supply copper, you are at risk of copper toxicity. A recent Nottingham University trial found that 70% of a sample of UK herds had signs of excess copper feeding, despite the farmer thinking they were feeding the correct level of minerals.”

There was more good news for livestock farmers this week too with straw and hay values both on the slide since the start of the summer.

Figures from the British Hay and Straw Merchants Assocation show that prices now stand at the lowest levels since autumn 2017, although still remain at historically high levels.

Industry reports also reveal increased straw availability as more has come on the market and a higher percentage of arable farmers having baled their straw instead of ploughing it in. At the end of July, values for big bale hay, barley and wheat straw were £90, £72 and £60 per tonne respectively against £95, £105 and £92 in the spring, and are continuing to slip.

Feeding for milk fat – nutrient checklist

Parameters Typical level

NDF (% DM)

(Neutral Detergent Fibre) >32

Acid load (g/kg DM) <45

Structural fibre (index) >110

RUFAL (g/kg DM)

(Rumen Unsaturated Fatty Acid Load) <25

DCAB (meq/kg DM)

(Dietary Cation-Anion Balance) >300

RFC (g/kg DM)

(Rapidly Fermentable Carbohydrates) <210