21 June 2002

Silage quality on the slide

By Richard Allison

and Jonathan Long

MANY dairy and beef units are seeing high yields of poor quality first cut silage this summer, forcing producers to reassess their winter feeding policy.

Numerous fields of grass have been cut for several days before being ensiled, says Kite Consultings Wilts-based adviser Edward Lott. "Several clients are also still waiting to cut grass, more than a month later than anticipated, due to poor weather."

This has resulted in poor quality silage, whereas crops taken in early May, when conditions were drier, are analysing well (see table). Later cut crops seem to have a reasonable fermentation, but digestibility is lower. The good news is that first cut yields are proving heavy, with many clamps being filled with first cut grass.

But heavy crop yields may catch out some producers, says Dorset-based senior Promar consultant James Shenton. "While crops are yielding more than 25t/ha (10t/acre) of freshweight, dry matter contents are low.

"What looks like a large heap could be used rapidly. It is crucial to have silage analysed and estimate dry matter yield before making winter feeding plans. Clamp losses are also likely to be high this winter with wet, low sugar grass.

"Where there is insufficient bulk, buying a standing crop of cereal for whole-crop will provide extra forage. Alternatively, consider brewers grains and sugar beet mix, says Mr Shenton.

But whole-crop cereal is not an option for producers in Wales, says Kite Consulting adviser and Pembrokes-based producer Grant Hartman. "One option is to take a high quality second cut crop. But this will be hard, as fields harvested two weeks ago have not greened up, further delaying second cut."

Mr Lott believes winter rationing with later cut silage will be a case of boosting energy levels by increasing concentrate levels. "Although many producers were hoping to minimise purchased concentrate use with the low milk prices, fortunately, cereal prices are low.

"Once silage analysis results are back, establish what feeds are needed to balance silage. When silage is at about 9.5MJ ME, it will take an increased level of a high-energy concentrate to achieve a whole ration energy content of 11-11.5MJ ME."

There are also good prices for protein feeds, with soya cheaper than last year. Mr Lott advises producers to fix prices now to avoid having to pay higher prices later this year.

Similarly, beef producers could compensate for poor quality silage by using cheap grain, says Signet beef consultant Ian Ross.

With forward wheat prices at about £55/t for August and barley at similar prices, Mr Ross believes that rations can be made for as little as £80/t, including processing. Other sources of energy and protein including brewers grains may be worth looking at, particularly with a view to stockpiling now for use later in the year.

But when silage is wet and acidic, cereals are not an ideal complement, as rumen acid loading will be high for dairy cows, warns Mr Shenton. "Fibrous feeds such as citrus pulp, soya hulls and sugar beet feed are more suitable.

"Excess rumen acid can now be more easily avoided with the recently launched Feed into Milk rationing system for dairy cows. The programme can help predict rumen acid loading, helping producers to feed wet acidic silage more safely."

Silage intakes could also suffer with wet, acidic silage. Including molasses or sugar beet pulp in the ration may help maintain intakes, says Mr Shenton.

Producers will also need to think about straw supplies this autumn, says Mr Ross. "If the wet weather continues, straw quality may be poor and supplies could be tight. Where possible, straw should be bought off the field to avoid disappointment later," he says. &#42

&#8226 Lower energy.

&#8226 More purchased feed.

&#8226 Plan now for winter.


May 4 June 4

Dry Matter (%) 25 21

Crude Protein (%) 18 12-13

ME (MJ/kg DM) 12.0 10.0