December 11, 2008

Dairy producers urged to scrutinize corn silage quality


This winter, dairy producers are advised to carefully analyse corn silage as recent studies show that current energy levels are considered be the poorest this century.


According to Rachel Fowers, ruminant specialist at Frank Wright Trouw Nutrition International, wet summer and low hours of sunshine during critical growth stages affect the quality and feed values, hence, delaying harvest.


Fowers added that out of the 660 silage samples analysed, ME (metabolisable energy) is about 0.5MJ (megajoules) down, while starch is 6 percent lower than last year, despite dry matter being reasonably close to the average. In addition, she said the intake potential is lower than usual which, together with the energy levels, suggests corn inclusion may not give yields the usual lift.


Mole Valley Feed Solutions' Dr Chris Bartram says many farmers may not achieve potential additional profit if producers don't immediately correct potential shortfalls in nutrition.


If milk production falls one litre a cow a day below target between December and April, Batram says the potential loss in gross margin across a 100-cow herd will be about 3000 British pounds (US$4,485). Unless the total diet is balanced to take poor-quality corn silage into account, he says performance may fall well below expectation.


Bartram states many herds are already struggling to find the right nutritional balance, which is already evident in a declining milk volume. The economics of the 'extra litre' is around the typical margin of 14 pence (p) a litre on a typical milk price of 27p a litre.


However, Fowers points out that although most corn silage is poor, some well-fermented crops have been made.


She said there are crops that have an ME of more than 12 and, with nearly 40 percent starch, some farmers will still see a response from corn. And if 5kg/DM (dry matter) is fed, Powers stresses the difference between the best and worst silages this year is more than two litres of milk.


However, for those planning to add higher starch concentrates to the ration to boost performance, acidosis may be a real issue, warns Fowers. Rumen buffers, she says, may be needed this year and the inclusion of protected fats could also help increase total energy intakes.


On the other hand, Bartram recommends producers to compare the current diet against a nutritional checklist of requirements. Key areas, he points out, is to focus on metabolisable energy, metabolisable protein and fibre nutrition, as well as major minerals, trace elements and vitamins


Variation between samples are whole-crop cereals should also be taken into consideration, says Fowers, although there is a huge variation on whole-crop samples which are similar to last year with 41.1 percent DM, 10.2MJ ME/kg DM, 9.5 percent crude protein and 19 percent starch.

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