Feeding Silage :
Feeding silage to sheep is an excellent way to economically mechanize and help reduce the manual labor
involved in feeding a large flock. Most producers have three concerns when first thinking about switching
their rations to a silage base. First, it takes a specialized set of equipment to plant, cultivate, and harvest
the silage. Second, the ewe needs to be handled properly in late gestation to prevent pregnancy toxemia.
Third, the threat of listeriosis from moldy silage.
Silage is the term used for the feed produced by controlled fermentation of high moisture herbage. When
silage is stored under anaerobic conditions (in the absence of oxygen) lactic acid is produced and will halt
the fermentation process. If silage is undisturbed it will keep for extended periods. There are now many
products on the market that are added to the silage at the time of putting in the silo that will increase the
quality of the silage by reducing fermentation, and some products such as urea (0.5-1%) or anhydrous
ammonia will actually increase protein. High quality silage is very palatable, and excellent results can be
achieved with ewes in their maintenance period or in early and mid gestation.
Corn silage is the most popular in the Midwest regions, but sorghum is used in drier climates with
success. Silage contains a moderate to high level of digestible energy, but is low to moderate in digestible
protein. As the corn matures the fiber content decreases and the energy content increases, this is directly
due to the increase grain content. As a rule, sorghum silage has a somewhat lower nutritive value than
corn silage. Corn silage is low in calcium and trace minerals and contains fair levels of phosphorus.
Additional calcium and trace minerals must be supplied. Crude protein of corn silage is 7-9% on a dry
Listeriosis is caused by a bacteria (Listeria monocytogenes) in sheep it usually causes brain related
clinical signs. Listeria can also cause abortion, diarrhoea and speticemia. It is commonly referred to as
“Circling disease” and silage is often the source of the listeria, but it can also be found in hay, or even on
sheep grazing pastures. The most common clinical signs are a sheep that walks in circles and has one
half of the face paralyzed. The affected ear and lips on one side of the face will hang, often the sheep is
drooling and the eyelid on the affected side will droop and the eye will also water causing the cheek to be
wet. Finally, after only one or two days the sheep will be found down and be paddling and unable to rise
on its feet. Treatment is dismal at best. Very early treatment with high doses of penicillin will save some
Listeria organisms are commonly found in the soil which has been contaminated with manure of
apparently normal carrier animals. When making silage it is very difficult to complete the job without some
soil contamination. If the silage is not properly packed tight to exclude oxygen, or the pH of the silage is
not low enough the Listeria will multiply in these small pockets. Sheep that are cutting teeth such as
newborn lambs, yearlings and mature ewes will have the greatest incidence via the bacteria getting in the
tooth socket and following the facial nerve to the brain. This will take 2-4 weeks after eating the affected
silage. Listeria is also a human pathogen.
Rules to help reduce Listeria in silage:
1. Feeding Silage: Reduce pocket gopher mounds in the field.
2. Feeding Silage: Do not cut silage too close to the ground.
3. Feeding Silage: Use a silage additive to lower the pH.
4. Feeding Silage: Pack tightly and seal air tight.
5. Feeding Silage: Test the pH value of silage, if the value is greater than 4.5, do not feed to the sheep.
6. Feeding Silage: Do not feed moldy or suspect silage to the sheep as it may cause health problems.
Silage should be considered for any producer feeding large groups of ewes that is looking to control feed
costs and labor. It takes increased management to handle, but the rewards will be well worth the extra
effort. Now, with silage bags a producer can hire some custom labor to chop and fill several silage bags
for a smaller or medium sized flock.