Wet first-cut silage prompts forage concerns

Farmers are being urged to assess their forage situation in light of wet first-cut silage taken earlier this year.

Results from 455 first-cut silage samples taken by Frank Wright Trouw Nutrition International show the wettest 20% of silages with an average DM of just 20.7%, compared with the overall average of 31.6%.

This could lead to reduced DM intakes and restricted milk output, unless producers plan now to balance out their winter rations.

The company’s technical director, Dr John Allen, says: “Silage cut on ‘typical’ first-cut dates was harvested in unsettled conditions, while farmers who left it later gathered crops in ideal weather and this is reflected in the analysis seen so far.”

And although the average DM content of 31.6% is only 1% lower than last year, there is a wide range in variation of silage quality, making it more important for farmers to get clamps analysed ahead of planning their winter rations, he adds.

“The wettest 20% of silages will certainly be the most difficult to feed. They will have a negative impact on rumen activity, cow performance and health and will need very careful balancing.”

In addition, there is an increased risk of rumen acidosis with wet silages due to higher lactic acid levels, and lower saliva production in cows eating wet feeds. Producers are advised to consider the addition of rumen active fibre such as straw or drier forages, as well as the use of rumen buffers or yeast.

Dr Allen adds: “Rumen bug activity will also be reduced leading to lower microbial protein production. To compensate it will be necessary to increase the supply of rumen energy in the rest of the diet, probably from digestible fibre, and by-pass protein, using rape, soya or a protected protein.

“Perhaps the most important thing now is for farmers to look at what they can do to improve the overall forage situation over the rest of the season as there is still time to improve overall stocks.

“If you have wet first-cut, try and take drier second cuts or look to make some cereal wholecrop forages as these have a higher dry matter and can promote better rumen function.”

FWTNI 1st cut grass silage averages to 22.06.12 

   Average  Wettest 20% Driest 20% 
 Dry Matter %  31.6  20.7  43.8
 Crude Protein %   14.4  14.9  14.0
 D Value %  69.4  68.1  70
 ME MJ/kg  11.1  10.9  11.2
 NDF %  44.3  45.3  43.5
 AD Lignin g/kg  47.8  39.0  47.5
 Sugar %  2.7  2.3 3.4
 pH  4.1 4.0 4.3
 Lactic Acid g/kg  73.6 111.1 45.7
 PAL meq/kg  733.5 930 668
 Intake Potential g/kg0  106.1 93.4 117.8