UK - An otherwise good first cut of silage could be let down by high fermentable carbohydrates and lower neutral detergent fibre on some UK farms.
Forage sampling data from Trouw Nutrition shows 2015 silage is high in energy and low in fibre, but the presence of highly fermentable carbohydrates, coupled with lower NDF, could put pressure on rumen health.
This is according to Trouw Nutrion’s ruminant manager, Adam Clay, who said nearly half of samples have a “good” metabolisable energy (ME) (11+) but that sub-acute rumen acidosis (SARA) could be a problem in some rations unless feeds are balanced with slower fermenting carbohydrates.
Commenting on the positives, Mr Clay said sporadic frosts through the winter meant grass was cut when young after fresh growth in May.
He said this had dropped NDF to an average of 46.8 per cent and increased ME to 10.9 MJ/kg/DM.
“Based on a daily intake of 10 kilos grass silage, this improvement in ME means cows will produce 0.4 litres/head/day more from grass silage,” he told the Livestock Event in Birmingham, UK, yesterday.
“Lower fibre and high energy density should help to stimulate milk production this season.
He highlighted good intake potential from samples as being important for supporting efficient production.
Protein content has improved from 13.7 per cent to 14.2 per cent, an indication of good clamp stability, he added.
But there is still reason to be cautious given the presence of highly fermentable carbohydrates and lower fibre levels.
And he said: “Butter fats and rumen health are at risk from higher sugars and higher fermentable carbohydrates.
“Watch out for loose dung and lower milk fats, another sign might be undigested feed in the dung."
He advised that these warning signs could be a sign that other carbohydrates are required.
He suggested farmers add treated wheat or barley to rations. Crimped or caustic maize could also take pressure off the rumen.
“For farmers looking to feed their own wheat and barley, soya hulls could work as a digestible fibre source low in rapidly fermentable carbohydrates. Sugar beet pulp is high in fibre but will also supply highly fementable carbohydrates."
Overall, he said the picture was positive, that cows will be “more enthusiastic” about eating large silage quantities and winter prospects are more encouraging that this time last year.
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