2 August 2002

FEED PLAN CUTS PROTEIN, BUT NOT PERFORMANCE

After four years of research

costing nearly £1m, a new

dairy rationing system will

begin offering benefits to

producers this winter, as

Richard Allison finds out

DAIRY cow rations may contain less expensive protein this winter without compromising cow performance, following the launch of a new feed rationing system.

Reducing protein intakes of cattle will help cut nitrogen pollution in slurry, says Devon-based independent nutritionist Geoff Hughes. "This is useful for many herds which face tighter rules with the extension of nitrogen vulnerable zones."

The new Feed into Milk (FiM) programme is allowing nutritionists to make better use of lower protein forages, minimising use of expensive protein feeds. This is because the model provides an improved estimate of the balance between energy and protein in the rumen, says Mr Hughes.

Rations with a protein content of 17% can provide sufficient metabolisable protein to maintain cow performance (see table). "This reduction in protein % from 19% may cut costs for one client by about £20/day, with 150 cows averaging 9500 litres."

But Mr Hughes believes some herds will continue to feed extra protein to take advantage of the small response in milk yield and milk protein. The model predicts what this response may be.

"This is valuable when evaluating rations and deciding the optimum protein level to maximise profit. However, care is needed as excess protein can lead to other problems, such as poor fertility."

Using the new FiM model, instead of the old UK rationing system, for one herd suggests cows need an extra 11MJ of metabolisable energy. But the challenge is to increase ration energy without compromising rumen function.

"Cows are fed a mixed ration based on high quality grass, whole-crop silage and caustic treated wheat grown on the farm. A high milk protein % is crucial to obtain a good milk price and fertility has always proved difficult to maintain."

One way to boost energy intake without impairing rumen function is feeding rumen-protected fat. Cereals are also useful for increasing energy and they can be used with more confidence as the FiM programme alerts producers to any risk of rumen acidosis with a ration.

The extra energy from the new ration could support an extra 2.5kg of milk and is likely to increase milk protein yield and %. "Although neither diet is likely to cause major problems, the FiM ration is more likely to promote cow fertility and milk protein, helping to increase my clients profit."

The system is also more accurate at predicting the balance between nutrients such as starch, sugars, fibre and oil. This is a more sensible approach than in the past and maximises rumen function, he explains.

"Many nutrition related problems are caused by poor rumen function, limiting the animals ability to extract nutrients from a ration."

While some experts use alternative rationing systems from the USA and France, the new system is better matched for UK conditions where grass silage is widely fed, says Mr Hughes. He believes it will cope with a wide range of yield levels and maximise milk from home-grown forage.

FiM is based on real cow data from more than 3300 cows, adds Mr Hughes.

&#8226 Milk producers can obtaina single farm version of thecomputer software costing £20 from the Milk Development Council (01285-646510; fax 01285 646501). &#42

&#8226 Based on UK data.

&#8226 Less protein needed.

&#8226 Lower ration cost.

The new Feed into Milk ration programme is allowing nutritionists to minimise use of expensive protein feeds this winter.


Old New system system

Energy supplied (MJ/day) 257 268

Crude protein (%) 19.3 16.7

Metabolisable protein (g/day) 2422 2423