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Processing Forages
by Naomi Paley, PAg
Regional Livestock Specialist,
Yorkton Office
Saskatchewan Ministry of Agriculture

Processing forages with bale shredders and tub grinders helps to reduce feed wastage especially when dealing with lower quality forages. Cattle are selective eaters. They will pick through the hay, leaving the coarse stemmy material behind.  Ground or chopped forage is consumed with minimal losses if feed is in a feed bunk or self-feeder. Feeding forage on the snow increases the amount of waste.  New research has shown when forages are rolled out onto snow, there is 12.3 per cent waste and 19.2 per cent waste when shredded onto the ground. If fed on snow, the fine material shorter than ¾ inch or 1.7cm cannot be picked out of the snow and creates 75 per cent of the wasted feed.  Generally this is the fine leaf material that is high in nutrients, especially energy and protein.

Processing forages and roughages allows for mixing. Good quality hay can be mixed with poor quality forages (slough hay, cereal straw and weathered hay) to provide a more balanced diet.

Over- and under-feeding can be avoided.  Grain and supplements can be added to the mix.

Processing reduces the ration bulk. Grinding forage through a 1.0 cm or 1.3 cm screen can increase the rate of passage through the digestive tract. Daily feed intake and rates of gain are increased. Chopping forage longer than 2.5 cm does not result in increased intake or rate of passage through the digestive tract. Grinding through a 0.5 cm screen (or finer) reduces the digestibility of the forage. Finely ground forage passes through the digestive system more rapidly, resulting in incomplete absorption of the digested feed. Processing a poorer quality forage increases intake to a greater degree than grinding high quality forage. The use of a 1.7 cm screen has the highest increase in digestibility for low quality forages.  

Twine is not generally considered a problem in feeding as long as it is cut into fairly short pieces (16 to 18 inches). Net wrap should be removed prior to processing.  There have been cases of dead cows from impaction due to larger pieces of net wrap clumping and blocking the digestive tract.

The occurrence of bloat may be increased when grinding good quality forages. Ground forage can be dusty. The incidence of respiratory problems and eye disorders may increase especially if the cattle are fed using bale feeders.   

Poisonous plants can pose problems. Cattle normally pick through long hay, leaving behind unpalatable material including poisonous plants. Processed forage is consumed without sorting. Ensure that the forage is free of poisonous plants.

Grinding forages can be expensive. Determine the advantages and disadvantages of processing.  If only poor quality or coarse stemmy roughage is available for your cow herd, grinding may be a useful option.