Anita O’Brien, Sheep and Goat Specialist, Ontario Ministry of Agriculture, Food, and Rural Affairs
(Previously published online as an OMAFRA publication: October 31, 2008)
Feeding haylage to sheep is less common than the feeding of dry hay rations. However, a number of producers have been feeding haylage to sheep in Ontario, causing more to consider it as a component of, or an alternative to their current feeding program.
This paper will be limited only to discussions on baled haylage, with limited references to conventionally stored haylage.
Why the Interest?
Baled haylage offers producers a greater flexibility in harvesting their winter feed supply, the potential for improved quality in feed, and less wastage from feeding. Baled haylage requires less drying time than conventional hay (50 to 60% versus 16 to 18% moisture), so that during poor drying conditions, quality feed can still be made. Because of the higher moisture content in baled haylage, there is less leaf loss (5 to 12%) during harvesting than with dry hay (22 to 26%). Since the protein content of the leaves is considerably higher than that of the stalks, less leaf loss means higher protein levels in the finished product. With quality baled haylage, very little wastage occurs at feeding, since the course, stemmy material is now softer and more palatable than with dry hay of similar makeup.
What are the Drawbacks?
Higher moisture content in baled haylage means a potential decrease in intake compared to dry hay, but certainly less than with chopped haylage. Some suggest that this is due to more chewing required for baled haylage which generates more saliva production that acts as a buffer against higher acid levels in the rumen. This buffering effect is important for optimal rumen microbial growth. No data are available on the extent that intake is reduced in sheep.
Exposure to oxygen will promote mold growth and spoilage. This is worse under conditions of high temperature and humidity. Amount of time required to consume the “face” of the baled haylage will influence the amount of spoilage. Ideally, the amount consumed per day should be enough so that little or no spoilage occurs. Individually wrapped bales would potentially have the least spoilage once opened until consumed, and a 5-4 stack would have the highest potential for spoilage (see factsheet: Harvesting and Storing Big Bale Haylage 88-094). Another problem with exposure to oxygen is heating, again due to mold growth. Heating is a greater problem with low-moisture baled haylage. The heating process binds some of the protein in the haylage, making this protein low in digestibility. If heating is occurring, it is advisable to have an ADF-N test done when forages are analyzed.
The biggest concern from a sheep perspective with spoiled, or poorly ensiled haylage is the risk of listeriosis. Listeriosis is caused by a bacteria (Listeria monocytogenes). Clinical symptoms include: depression (inactivity), weakness, paralysis of the tongue and jaw, blindness and drooling. Animals lack co-ordination, lose their appetite, walk in circles and push their heads against fences and other objects. Death sometimes occurs before any, or all of the other symptoms are apparent.
Incubation period is approximately 3 weeks after ingestion of the feed containing listeria bacteria. It is important to remember, therefore, that when a outbreak occurs, the silage which caused the problem was probably fed 3 weeks previous.
Although not as common as the above mentioned symptoms, listeria abortion may occur in ewes, usually in the last third of pregnancy. Abortion occurs 10 to 18 days after the bacteria gain entry to the bloodstream. Following abortion, most ewes usually recover fully.
The bacteria causing the disease will not survive in silage where the pH is below 5.6. Most baled haylage, however, will have a pH higher than 5.6, theoretically increasing the risk of listeriosis. The bacteria will survive in pockets of spoiled haylage, such as the bag closure and any punctures that have allowed air in. Remember that spoiled haylage left in the feeders can contaminate good quality haylage, resulting in perpetuation of the problem. Because the ensiling process takes up to 3 weeks to complete, listeria may be present during this time period, since the pH won’t necessarily have dropped below 5.6 during this time. Make sure you wait at least 3 weeks for proper ensiling to occur before feeding.
Several management practices will help reduce the risk of losses to Listeriosis. Some of these are listed as follows:
1. Always be conscious of the risk of listeriosis
2. Do a top job of harvesting and storing haylage
3. Check bags frequently for holes and seal promptly
4. Never feed spoiled haylage to sheep
5. Wait at least 3 to 4 weeks after ensiling before feeding
6. Start sheep onto haylage gradually (as with all feed changes)
7. Provide plenty of clean drinking water
8. Use a feeding system that minimizes waste and trampling
9. Clean up refused feed regularly
10. Isolate and treat sick animals
11. Remember that the disease is contagious to humans as well – Use care when handling sick animals
Baled haylage provides more flexibility in forage harvesting than does dry hay. It also gives the potential to harvest higher quality forages, so that nutritional needs of the late pregnant and lactating ewe are more easily met. Because of the risk of listeriosis, emphasis must be placed on proper harvesting and storage to ensure a top quality haylage is made. Even with the risk of listeriosis, haylage can be successfully used in sheep feeding programs when care and attention are paid to the feeding management of the flock.