22 March 1996


If you have a feeding set-up that works, dont rush to change to a complete diet system. Jessica Buss reports that the money might be better spent in other ways

SWITCHING to a complete diet feeding regime can demand large scale investment. Producers should consider the return that is needed to justify this investment and whether the money could be invested in a better way.

This is the advice of Andersons dairy consultant Mike Houghton.

"There is a lot of pressure to change to complete diet feeding," he says. "And there is no doubt that this is the best way to feed dairy cows."

He cites the advantages of complete diet feeding as more contented cows, reduced lameness and that concentrates offered evenly throughout the day are better for the cows digestion.

Wrong reasons

"But producers start complete diet feeding for the wrong reasons and often end up doing it badly – spending more on concentrate a tonne and decreasing yield from forage. With complete diet feeding yield from forage reduces more often than it improves. But it tends to increase feed intakes and therefore raise yields."

"Changing from self-feed silage and parlour cake to CDF may cost £15,000. For an 80-cow herd this means that a £192 increase in margin over purchased feed is needed to break-even," he says (see Table 1). "So at 80 cows it is often uneconomic to buy a complete diet feeder or alter the feeding system to cope with the feeder. The money could probably be spent better.

"On a 160 cow herd it may be viable as only a 380-litre yield increase is needed to cover costs."

However, he stresses that efficiency can often be improved on existing feeding systems. "Margin over purchased feed accounts for 79% of the herd/farm gross margin. But Genus Milkminder and ADAS Milk Cheque figures show that over the last 12 months there has been no increase in efficiency although margins have risen every month due to milk price."

Mr Houghton believes that cow management accounts for 80% of cow performance. But this is not at its best on many units, and yields from forage could be improved with the cows available without changing the feeding system. "Producers making good yields from forage are those making good profits."

One area that is neglected is the cost of producing silage and the waste that occurs. "Silage is expensive to produce at £20/t or about £80-90/t of dry matter. So when you are wasting about 10%, it may be cheaper to buy in brewers grains at £18/t than to make silage."

Doubtful benifits

While maize has improved many cow diets, Mr Houghton has yet to be convinced of the benefits of whole-crop wheat. When it is harvested as grain and straw it can still be fed to stock – there is less waste and surpluses can be sold more easily.

He also suggests that changing from self-feed silage to an easy feeding system will help improve use of forage for 6000-litre average yield herds.

"This may be of more benefit than spending £15,000 on a complete diet feeder," he adds.

However, when producers have a forage box that needs replacing, the increases in performance needed to justify the investment are lower.

"Producers who are forage box feeding can afford to upgrade to diet feeder if the forage box is wearing out" (see Table 2).

&#8226 More machinery – loader and tractor.

&#8226 Extra labour.

&#8226 Higher level of management and more management time.

&#8226 More space at feed barrier.

&#8226 Straights storage.

&#8226 Flexible cashflow for buying straights.

&#8226 Cow grouping/housing facilities.


Table 2: Break-even point for changing to CDF from a forage box system*

Herd size


Increase needed in:

Margin/cow (£)785240

Extra litres/cow

@ 25p/l)itre312208160

Conc price


(£/t)4329 22

*Table assumes cows average 6000 litres off 1.8 t of concentrate

Table 1: Break-even point for changing to CDF from self-feeding*

Herd size


Increase needed in:

Margin/cow (£)19212896

Extra litres/ cow

(@ 25p/litre)768512384

Conc price

reduction (£/t)1067153

*Table assumes cows average 6000 litres off 1.8t of concentrate

How do they compare?Diets

Management considerationsSelf FeedEasy FeedComplete

Equipment costLowLowHigh

Labour inputLowHighHigh

Feeding to yield potentialHighHighLow

Ease of use for mixed foragesLowLowHigh

Potential for different concsLowMediumHigh

Suitability for by-productsLowLowHigh

Feed passage needsLowLowHigh

Grouping facility requirementLowLowHigh

When cow management accounts for 80% of performance, yields from forage can often be improved without changing the feeding system. Bigger herds are generally likely to have more to gain from making the switch.