Dairy farmers should plan carefully ahead to ensure cows get the right nutrient balance, warned nutritionists Frank Wright Trouw Nutrition on the opening day of Livestock 2012.
Following the analysis of a collection of 4,000 first-cut samples and 400 second-cut samples the company said the wet weather had affected silage quality and farmers would face a variety of challenges this winter.
“On average first cuts were better than second cut crops in all key areas such as dry matter, ME, protein and intake potential,” said ruminant manager Adam Clay.
“The average ME is lower than last year’s average, reflecting the delayed cutting date of many crops which shows as higher NDF levels,” he added.
But Mr Clay warned overall there had been a huge variation in quality and it was vital farmers had their clamps analysed regularly during the winter to allow them to fine-tune diets.
Mr Clay said the biggest concern was wet silages.
“Generally the wet silages have a low intake potential and a lower ME. They also have lower levels of rumen energy which will reduce rumen activity and microbial protein production.”
Mr Clay said wet silages represented a challenge to rumen efficiency and silages with low Ph, down to 3.5, combined with high lactic acid levels presenting a high acidosis risk.
To counter this Mr Clay said farmers should feed wet silage with drier forages, including chopped straw or feeding rumen buffers and yeast.
“Very wet, acidic silage should not be fed to early lactation cows if possible,” he warned.
However it wasn’t all bad news. Mr Clay said they had seen some very dry crops, which would generally feed well and have good intake potential, with a low acid load which bodes well for rumen health.
But he said heating at the clamp face was already being reported and warned careful clamp management would be required to avoid secondary fermentation and waste.
He added: “Mouldy silages will suppress intakes so make sure the clamp face is kept compacted and moves back quickly. If feeding a TMR the target overall dry matter for a good mix is around 40-45% so it might be sensible to add water to the diet to ensure good mix when using dry silages.”
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