 | When the milk line is about ½ down the kernels through the black layer stage. |
| When silage is approximately 35% DM. |
Cliff’s Notes: Top 10 List for Good Corn Silage
Clifton L. Willms, Ph.D., P.A.S.
Cattle Nutritionist
| When the milk line is about ½ down the kernels through the black layer stage. |
| When silage is approximately 35% DM. |
|
Approximate DM Content of Corn Whole-Plants and Ears at Different Reproductive (Ear) Stages |
||
|
Ear stage |
Whole-plant |
Kernels |
|
------- % of the DM ------- |
||
|
Blister (R2) |
17 |
15 |
|
Early-milk (R3) |
20 |
20 |
|
Dough (R4) |
23 |
30 |
|
Early-dent (R5) |
25 |
50 |
|
Milk line ½ down |
32 |
60 |
|
Milk line ¾ down |
36 |
65 |
|
Black layer |
38 |
70 + |
|
Field Guide for Hay and Silage Management. 1991. KK Bolsen, ed., NFIA. Chapter 3. |
||
| Harvest drought stressed corn early to help conserve leaves and stalks. Be cautious of nitrates per discussion below. |
| Sharp knives work best. |
| Get the cobs chopped in small pieces so cattle don’t sort them out at the feed bunk. |
| When plants are chopped and crushed, a lot of enzymes are released. Two major things are happening while exposed to air that are driven by plant enzymes - - - respiration and protein breakdown. |
| Filling rate is directly related to amount of initial heating and respiration losses. |
| Respiration accounts for considerable DM and sugar losses. |
| Getting another layer of fresh silage allows for anaerobic conditions to quickly be established. Trapped oxygen is quickly used up and respiration ceases. |
| People have harped on this point forever and it can’t be over-emphasized. It is still one of the biggest mistakes seen in the field. |
| If you can still see the tire tracks in a bunker silo, it isn’t packed well enough. |
| The key to a good fermentation is establishing a homofermentation (dominance of organisms that produce only lactic acid) rather than a heterofermentation (yeasts, molds, and clostridial organisms that produce ethanol, butyric, carbon dioxide, acetic acid, etc. as well as lactic acid). |
| Lactic acid bacteria that produce only lactic acid from glucose and other sugars are homofermentive. |
| Lactic acid is preferred because it is a stronger acid and will drop pH faster, stop fermentation activity, and preserve the forage crop. |
| Spoilage (loss of organic matter) in the top 18" was reduced from 49% for uncovered corn silage to 31% for covered corn silage. Spoilage in the next 18" was reduced from 9% to 1%. (KSU Cattlemen’s Day. 1991. p. 70.) |
| Spoilage is a key factor that makes the real cost of silage expensive! |
| With all of our technological advances, the best way still seems to be black plastic and tires. Splitting tires prevents them from holding water after rains and from mice taking up residence. |
| Interesting note: A feeder had 3 bunker silos. One with sorghum silage, one with corn silage, and one with corn silage with 12" of sorghum silage on top of the corn silage. All were covered with black plastic and tires. Raccoons and deer tracked all over the corn silage but the other two silos with sorghum silage or 12" sorghum were left alone. |
| Ammoniation may increase crude protein content and improve bunk life of the silage, but it is going about things backwards. |
| Ammoniation increases the pH of the silage and interferes with achieving a primary objective in good silage making. A good homofermentation of silage drops pH quickly. A rapid drop in pH stops the fermentation process so that a lot of nutrients are not used up. |
| Crude protein is increased, but it is in the form of non-protein nitrogen (NPN). NPN is best used in high grain rations. So when one can make the best use of NPN, rations are limiting in silage and vise versa. Further, the many protein-degrading enzymes are released from plant cells when the crop is chopped, crushed, and packed. Therefore, most of the nitrogen in silage is already in a NPN or soluble protein form. |
| There is no advantage nutritionally to adding NPN at ensiling vs. at the time of feeding. One will still need to use a supplement of some type at feeding, so no labor or convenience is achieved by ammoniating silage. |
| Usually not a problem in silage because the fermentation process will decrease nitrates by about 50% from the level in fresh forage. |
| In drought stricken forage, it takes 5 to 7 days for the plant to metabolize the nitrates after a good rain. |
| If nitrates are a concern, one can raise the cutter bar a few inches and reduce the nitrate level. Nitrates are concentrated in the bottom of the stalk. |
| Nitrates can be analyzed as nitrate, nitrate-nitrogen, or potassium nitrate depending on the analytical method a lab chooses to use. Each method is equally valid. The important point is knowing how to interpret the values. The following table shows equivalent values for each method. |
|
Guidelines for interpreting nitrate analysis |
|||
|
Nitrates |
Nitrate nitrogen |
Potassium nitrate |
|
|
NO 3 |
NO 3 – N |
KNO 3 |
Comments |
|
----------- ppm, DM basis ----------- |
|||
|
0 - 4400 |
0 - 1000 |
0 - 7200 |
Safe |
|
4400 - 6600 |
1000 - 1500 |
7200 - 10800 |
Safe to non-pregnant animals Limit to 50% in pregnant animals |
|
6600 – 8800 |
1500 - 2000 |
10800 - 14400 |
Limit to ½ of the ration DM Do not feed to pregnant animals |
|
14400 – 25200 |
Limit to 1/3 of the ration DM |
||
|
8800 - 17600 |
2000 - 4000 |
25200 - 28800 |
Limit to ¼ of the ration DM |
|
> 17600 |
> 4000 |
> 28800 |
Do not feed |
| This starts with the right structure for storing silage. Making a "ball" out on bare ground increases total exposure and there is no way to have a small area exposed when you get half of the silage fed. |
| Wide bunkers are safer at silo filling time, but they allow a tremendous amount of face exposure. The silo needs to be wide enough to be safe, but narrower than many seen in the country for reducing face exposure. |
| It’s a dangerous job: from silage choppers that plug, to hauling on country roads with blind corners, to a lot of traffic flow around the silo and feed yard, to twisting hoists when dumping silage trucks, to packing silage - let’s use our heads. Silage cutting involves a large crew and if an accident happens, it will involve a family member or a close friend! |
| Silage cutters have a lot of moving parts – don’t stick your hand in someplace where it doesn’t belong – hands don’t make very good silage. |
| Piling silage high and well above the sides of a bunker is dangerous. We don’t need any tractor rollovers when packing (falling silage when feeding out can be bad, too). |
| Stay out of upright silos after filling to avoid toxic gasses and suffocation. |
| You name 10 more safety issues and review with your crew! |
