Feed Can cut performance and may permanently damage cattle.
Take Home Messages
Effect of level of spoiled maize silage
on dry matter intake and nutrient digestibility
Dr. Keith Bolson of North Carolina summarized the effect of feeding spoiled silage from the top of maize silage clamps. The top three feet of maize silage in a bunker was allowed to spoil and fed to steers fitted with rumen cannulas.
Four diets were fed
Feed results are summarized
in Table 1.
Table 1. Effect of level of spoiled silage on dry matter intake and nutrient D Value
In the US it is not
uncommon to find maize clamps unsheeted. What will deliver the same thing in the
Strategies to minimize
storage moulding in any feed include:
The most damaging of
Aflatoxin & Ochretoxin - these
are storage toxins from moulding of grains / straights in damp warm
conditions - they can be carcinogenic or permanently damage the liver.
Ammonia and possibly urea treatment can denature Aflatoxin.
Ochretoxin shows up in milk - there are strict EC standards for
Ochretoxin and Aflatoxin.
DON - or Vomitoxin - a field
toxin from fusarium (head blight - head scab) in wheat can give rise to
digestive upsets particularly in the young ruminant and mono gastric.
DON has not shown up in milk. There
are lots of other causes of digestive upsets - (Lack of effective fibre,
excessive grains, disease) but if these are ruled out through careful feed /
diet management then DON or some other mould should not be discounted.
There are other mycotoxins from
fusarium that can effect fertility
What's the position in the UK?
a survey showed storage mycotoxins are at low levels in well dried and
cooled grain held in damp proofed non-leaking stores. However, we all recognise
that dairy farmers for the most part are not arable farmers.
The old covered silage pit
converted to grain store next to the new silage pit generally runs wet, roofs
leak, space boarding lets in horizontal rain and when the door is left open the
dog / cat or starlings crap all over.
For long term storage dry cereals
need to be cool - under 10C AND
17-18% moisture with low volume
ventilation max 6 months
15% Max moisture for all year -
Inappropriate moisture content /
application rate / sheeting for any crimped, caustic, urea
innoculant or propcorn treated grain has the potential to deliver a
potentially nasty mould.
Aim for a feed out rate of 1ft per
day for damp treated products other than caustic grain.
This means long narrow mini bunkers.
Any fermented product is going to be attractive to vermin - much less so
caustic or urea treated whole grains.
Field Toxins - Fusarium. spp
The Maize Wheat Maize Wheat
rotation has but one weakness - fusarium. A
spray with Amistar and Caramba when the wheat head has just fully emerged from
the stem is essential.
Where there is sufficient
acreage to more than fulfil starch and fibre requirements then pulses and
linseed ( Not OS Rape) should be
The following rotations are
recommended to minimise fusarium
No Grass With Maize:
No Grass Without Maize
Conventional wisdom would
discourage these rotations for sclerotinia disease, which attacks most
crops. Conventional advice is to
grow no legume within 5 years of another. If
sclerotinia does become established - then seed yield can be savaged -
then will be time to widen the gap.