Silage DMD is the percentage of dry matter that is actually digested by the animal. The higher the DMD, the higher the performance of your animals will be. Cutting date is the most important factor in making quality silage and for each week delay it will result in a 3-unit drop in DMD at feeding out time. If crop lodging occurs when grass gets flattened due to heavy rain, this can result in a 9-unit drop in DMD for every week that harvest is delayed. Walk the silage fields regularly at this time of year and look for the presence of seed heads and dead material at the base of the crop. Aim for a short fast wilt of 24-36 hours. Prolonged wilting will result in lower DMD values.
Yield v quality
While many farms will be concentrating on building fodder stocks back up, this should not be at the expense of making good-quality silage. At a minimum, a plan should be put in place to earmark some fields to make high DMD silage for priority stock. Drystock farms should be targeting 75DMD silage for finishing animals to reduce concentrate inputs. Seventy-two DMD should be targeted for weanlings or growing cattle. Dry spring calving suckler cows will suffice with 66DMD silage. Table 1 highlights liveweight gain with different DMD silage.
Preservation
Grass sugars are converted to acid during the fermentation process and this acid aids the preservation process. The target sugar content of a silage crop should be in excess of 3%. This can be tested by cutting a grass sample from the field, extracting the juice and using a refractometer to determine sugar content. Ryegrass swards, dry sunny weather and mowing grass in the afternoon will all help to ensure high sugars at harvest time.
Nitrates can be tested using nitrate test strips. A good growing crop will use two units per day of nitrogen. Sugars are more important than nitrate levels and a crop with good sugar levels can still be harvested with elevated nitrate levels. A good wilt will also help.
Using an additive – yes or no?
High leaf content, a short fertiliser spreading to cutting interval and poor sunshine can all lead to poor ensiling conditions. In some instances, an additive may be required to ensure good preservation. If sugars are below 2% an additive will be required. This can be in the form of molasses, acid, absorbent or inoculant. If sugars are between 2-3% and wilting is not an option, an additive may be required.
If wilting is an option, this will suffice for good ensiling conditions. If sugars are above 3%, no additive is required.
Rolling the pit
Filling silage pits has gotten a lot quicker in recent years as weather windows get tighter and conttactors get busier. Filling a silage pit too fast will have a negative impact on the level of compaction that can be achieved. Grass should be applied in layers of 9in. If grass is filled any deeper, it will be harder to compact successfully.
Grass should then be continuously rolled as loads come in and are layered into the clamp. If the pit is not rolled adequately air pockets will form and these will have a negative impact on the preservation of the silage.
Once the pit has been filled, roll for one to two hours before covering as quickly as possible to avoid air being sucked down into the pit.
Sealing and covering
It is difficult to get a proper seal between the side wall and top of clamp without a side sheet of plastic. The side sheet should overlap the top of the clamp wall by at least 1-2m, and sandbags should be placed at the edge of the wall along the join of the two sheets to form a seal. This will stop oxygen entering the silage.
A side sheet will also help protect the concrete silo wall from silage effluent that can erode the concrete. This will help prolong the life of the silage pit. It’s important to make sure that along the wall is sealed well with sandbags as this can be an area where air can get in and create waste silage.
Covering with two covers is good practice; one new cover first and then an old cover second. This helps protect the new cover from any holes. Adequate compaction and weight is important to get a good seal. Silage mat products have become very popular but tyres are still the most commonly used. Tyres need to be placed edge-to-edge at a minimum. If a pit sinks a lot over a few days, best practice is to tighten the cover further with sand bags along the side. Eliminate all points of air entry through effluent channels etc. Make sure to take extreme caution when covering a pit. Walls and a safety rail will make covering a pit a lot safer.
Round bale silage tips
Aim to mow in the afternoon and aim for a short fast wilt of 24-36 hours. Avoid driving the tractor at excessive speed when baling as this will lead to poorly shaped and poorly packed bales that may have issues with preservation. Use a minimum of four layers of plastic and if bales are to be stored for prolonged periods, use six layers. Take care when transporting bales to avoid any damage.
Top tips
Walk silage fields regularly to assess ear emergence, lodging and dead material at base.Target sugars above 3% at cutting time.If sugars are below 2%, use a form of additive.Mow grass in afternoon if possible.Aim for a short fast wilt of 24-26 hours.Roll the pit at filling and cover quickly.Check pit for sinkage and tighten cover appropriately.
Silage DMD is the percentage of dry matter that is actually digested by the animal. The higher the DMD, the higher the performance of your animals will be. Cutting date is the most important factor in making quality silage and for each week delay it will result in a 3-unit drop in DMD at feeding out time. If crop lodging occurs when grass gets flattened due to heavy rain, this can result in a 9-unit drop in DMD for every week that harvest is delayed. Walk the silage fields regularly at this time of year and look for the presence of seed heads and dead material at the base of the crop. Aim for a short fast wilt of 24-36 hours. Prolonged wilting will result in lower DMD values.
Yield v quality
While many farms will be concentrating on building fodder stocks back up, this should not be at the expense of making good-quality silage. At a minimum, a plan should be put in place to earmark some fields to make high DMD silage for priority stock. Drystock farms should be targeting 75DMD silage for finishing animals to reduce concentrate inputs. Seventy-two DMD should be targeted for weanlings or growing cattle. Dry spring calving suckler cows will suffice with 66DMD silage. Table 1 highlights liveweight gain with different DMD silage.
Preservation
Grass sugars are converted to acid during the fermentation process and this acid aids the preservation process. The target sugar content of a silage crop should be in excess of 3%. This can be tested by cutting a grass sample from the field, extracting the juice and using a refractometer to determine sugar content. Ryegrass swards, dry sunny weather and mowing grass in the afternoon will all help to ensure high sugars at harvest time.
Nitrates can be tested using nitrate test strips. A good growing crop will use two units per day of nitrogen. Sugars are more important than nitrate levels and a crop with good sugar levels can still be harvested with elevated nitrate levels. A good wilt will also help.
Using an additive – yes or no?
High leaf content, a short fertiliser spreading to cutting interval and poor sunshine can all lead to poor ensiling conditions. In some instances, an additive may be required to ensure good preservation. If sugars are below 2% an additive will be required. This can be in the form of molasses, acid, absorbent or inoculant. If sugars are between 2-3% and wilting is not an option, an additive may be required.
If wilting is an option, this will suffice for good ensiling conditions. If sugars are above 3%, no additive is required.
Rolling the pit
Filling silage pits has gotten a lot quicker in recent years as weather windows get tighter and conttactors get busier. Filling a silage pit too fast will have a negative impact on the level of compaction that can be achieved. Grass should be applied in layers of 9in. If grass is filled any deeper, it will be harder to compact successfully.
Grass should then be continuously rolled as loads come in and are layered into the clamp. If the pit is not rolled adequately air pockets will form and these will have a negative impact on the preservation of the silage.
Once the pit has been filled, roll for one to two hours before covering as quickly as possible to avoid air being sucked down into the pit.
Sealing and covering
It is difficult to get a proper seal between the side wall and top of clamp without a side sheet of plastic. The side sheet should overlap the top of the clamp wall by at least 1-2m, and sandbags should be placed at the edge of the wall along the join of the two sheets to form a seal. This will stop oxygen entering the silage.
A side sheet will also help protect the concrete silo wall from silage effluent that can erode the concrete. This will help prolong the life of the silage pit. It’s important to make sure that along the wall is sealed well with sandbags as this can be an area where air can get in and create waste silage.
Covering with two covers is good practice; one new cover first and then an old cover second. This helps protect the new cover from any holes. Adequate compaction and weight is important to get a good seal. Silage mat products have become very popular but tyres are still the most commonly used. Tyres need to be placed edge-to-edge at a minimum. If a pit sinks a lot over a few days, best practice is to tighten the cover further with sand bags along the side. Eliminate all points of air entry through effluent channels etc. Make sure to take extreme caution when covering a pit. Walls and a safety rail will make covering a pit a lot safer.
Round bale silage tips
Aim to mow in the afternoon and aim for a short fast wilt of 24-36 hours. Avoid driving the tractor at excessive speed when baling as this will lead to poorly shaped and poorly packed bales that may have issues with preservation. Use a minimum of four layers of plastic and if bales are to be stored for prolonged periods, use six layers. Take care when transporting bales to avoid any damage.
Top tips
Walk silage fields regularly to assess ear emergence, lodging and dead material at base.Target sugars above 3% at cutting time.If sugars are below 2%, use a form of additive.Mow grass in afternoon if possible.Aim for a short fast wilt of 24-26 hours.Roll the pit at filling and cover quickly.Check pit for sinkage and tighten cover appropriately. 
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