Questions and answers on producing high quality silage
Sandra Wick, Crop Production Agent
Some producers have started fall harvest while others are just gearing up for this busy time of the year for farm families! Also on many producers’ “to do” list is the task of putting up some of their crops for silage for their cow herd. The following are some questions you may have dealing with silage production and management.
What is the proper size for a bunker, trench, or pile silo? The tons of crop to be ensiled and the projected tons of silage to be fed daily determine the proper size for a bunker, trench, or pile. The height, width, and depth dimensions should be small enough to allow a rapid progression through the silage mass during the feed-out phase. Most silos are too large-- they take too long to fill, and the feed-out rate is too slow.
How does the type of silo affect “losses” and “silage quality?” The type of silo does affect “losses” and “silage quality;” however, minimum losses and high quality silage can be achieved in any type of silo—if it is well managed. In general, vertical silos (towers) are more efficient than horizontal silos (bunkers, trenches, piles and bags), and smaller-capacity silos are less efficient than larger-capacity silos (if filling is not delayed and the silage removal rate is not too slow). “Forage in” versus “silage out” losses range from as low as 5 percent to more than 40 percent.
How do I manage the silage “face” during the feed-out phase? The silage “face” should be maintained as a smooth surface that is perpendicular to the floor and side walls (in bunker and trench silos). This will minimize the square meters of surface that are exposed to air. The rate of progression through the silage mass must be sufficient to prevent the exposed silage from heating and spoiling. An average removal rate of 8 to 12 inches from the face per day is a common recommendation.
Some producers have started fall harvest while others are just gearing up for this busy time of the year for farm families! Also on many producers’ “to do” list is the task of putting up some of their crops for silage for their cow herd. The following are some questions you may have dealing with silage production and management.
How do sorghums compare to corn as silage crops? Grain sorghum compares very favorably to corn as a whole-plant silage. Grain sorghum should be harvested at the mid- to late-dough stage of kernel maturity. It usually has a higher crude protein (CP) content than corn silage, but slightly lower net energy values for beef and dairy cattle. The agronomic and nutritional quality traits of forage sorghum silages are far more variable than those of whole-plant corn or grain sorghum silages. Therefore, hybrid or variety selection is critical for forage sorghum, and a good rule-of-thumb is to avoid the phenotypic extremes.
Is it better to harvest (ensile) the silage crop too early or too late? For corn, sorghum, and small grain cereals, it is probably better to harvest too early rather than too late, but excessive effluent must be avoided (i.e., do not harvest above 70 to 72 percent moisture). The earlier-harvested silage will have a lower pH, a higher acid content, and the chance of a greater DM loss in the silo than later-harvested silage. The later-harvested crop will be more difficult to chop and pack, and the drier silage will be more aerobically unstable during the feed-out phase than earlier-harvested silage.
What is the proper size for a bunker, trench, or pile silo? The tons of crop to be ensiled and the projected tons of silage to be fed daily determine the proper size for a bunker, trench, or pile. The height, width, and depth dimensions should be small enough to allow a rapid progression through the silage mass during the feed-out phase. Most silos are too large-- they take too long to fill, and the feed-out rate is too slow.
How long after filling can the silo be opened for feeding? The fermentation phase should be completed before the silo is opened for feeding. This normally takes two to three weeks after filling. If silage is fed after only a few days in the silo, DM intake is likely to be affected adversely. Inoculants should reduce the time required for the fermentation phase to be completed. Because grasses and legumes usually ferment slower than corn (or sorghum), grass or legume silages should not be fed until at least three weeks after filling.
What are the losses in a very good silage? The losses in a very good silage will range from 5 to 15 percent, whereas the losses in a very bad silage will range from 25 to 50 percent. Loss is defined as the amount of forage DM that is put in a silo minus the amount of silage DM that is removed from the silo and fed.
How does the type of silo affect “losses” and “silage quality?” The type of silo does affect “losses” and “silage quality;” however, minimum losses and high quality silage can be achieved in any type of silo—if it is well managed. In general, vertical silos (towers) are more efficient than horizontal silos (bunkers, trenches, piles and bags), and smaller-capacity silos are less efficient than larger-capacity silos (if filling is not delayed and the silage removal rate is not too slow). “Forage in” versus “silage out” losses range from as low as 5 percent to more than 40 percent.How do I manage the silage “face” during the feed-out phase? The silage “face” should be maintained as a smooth surface that is perpendicular to the floor and side walls (in bunker and trench silos). This will minimize the square meters of surface that are exposed to air. The rate of progression through the silage mass must be sufficient to prevent the exposed silage from heating and spoiling. An average removal rate of 8 to 12 inches from the face per day is a common recommendation.
If you have further questions on silage production and management for your cattle herd, contact any Post Rock Extension District Offices in Beloit, Lincoln, Mankato, Osborne or Smith Center.
Post Rock Extension District of K-State Research and Extension serves Jewell, Lincoln, Mitchell, Osborne, and Smith counties. Sandra may be contacted at swick@ksu.edu or by calling Smith Center, 282-6823, Beloit 738-3597, Lincoln 524-4432, Mankato 378-3174, or Osborne 346-2521. Join us on Facebook at “Post Rock Extension” along with our blog site at postrockextension.blogspot.com. Also remember our website is www.postrock.ksu.edu and my twitter account is @PRDcrops.
