Distillers’ grain is a by-product of ethanol production. Corn, wheat and barley are the grains
that are generally used in the distillery process. Distillers’ grain is rich in protein and
phosphorus. The mineral content and amino acid composition of distillers’ grain are
proportionate to the content and composition in the original grain. Both wet and dry distillers’
grain is used as feed for farm animals.
The purpose of the thesis was to investigate how dairy farmers store, deal with and feed
distillers’ grain to dairy cows. Knowledge about feeding with distillers’ grain was gained
from study visits to dairy farms and interviews with dairy farmers, advisors and veterinarians.
The aim of collecting this information was to be able to give dairy farmers qualified advice
about distillers’ grain.
The wet wheat distillers’ grain (WWDG) from Vin & Sprit AB´s distillery in Nöbbelöv,
Kristianstad, contains dry matter (DM) of 8-9 % making it possible to pump. When WWDG
leaves the distillery it has a temperature of around +25 °C. Analysis of the WWDG produced
in week 21, 2007 showed that the crude protein content was 430.4 g per kg DM and the
neutral detergent fibre (NDF) content 355.4 g per kg DM. WWDG has a pH of around 4, in
low pH only lactic acid bacteria can grow if the temperature is over +15 °C. The crude protein
of WWDG is of rumen degradable character which can affect the value of urea in milk.
Amino acid composition of the WWDG is not optimal for lactating dairy cows when the first
limiting amino acid is methionine. The phosphorus content of WWDG is higher than that of
calcium.
In studies, WWDG from Nöbbelöv has been stored for up to eight weeks without any signs of
bacteria growth, apart from that of lacto acid bacteria. At the visited farms, the longest storage
period was between 3 to 4 weeks. That farm had a cell content in milk of around 50 000 cells
per ml milk. During storage, the WWDG loses its palatability.
WWDG is easily stored in tanks under- and above-ground. It is important that the tank is
emptied properly of WWDG to minimize possible bacteria growth. The WWDG easily
settles, and this is prevented by stirring. The nutritional value of settled WWDG changes
because of the change in DM and the diet becomes suboptimal.
When WWDG is a component of the diet it is important that the other feed complements
WWDG content of NDF, rumen-degradable protein and phosphorus. Suitable feeds are grass
and corn silage, beet by-products, feeds with low crude protein content and minerals with a
low phosphorus content. It is important that the roughage is of good structure as this
stimulates rumination. It is beneficial if some straw is fed to give good structure to the rumen.
A feed amount of 10-15 kg WWDG per day is suitable for lactating cows. At the visited
farms, WWDG was fed in troughs, cribs and in partly mixed ration (PMR) or total mixed
ration (TMR) made in feed mixers. To prevent over-consumption of WWDG, the only
alternative is feeding with feed mixers. In PMR and TMR, wet distillers’ grain is a good
substrate to adjust the DM of the feed mix and increases palatability of the feed mix. It is
important that the DM does not drop to below 30 %; if this happens the feed will lose its
palatability. WWDG can never compensate free access to fresh water for animals.
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When WWDG is mixed with other feeds or water, the low pH will increase. At higher pH the
WWDG is a very good substrate for nutrition, and micro-organisms can grow. To prevent the
growth of micro-organisms and affected udder heat when feeding with WWDG, it is
important to maintain good hygienic conditions around feeding equipment, feeding places,
resting areas, milking an...
