I love silage. No, I don't mean for myself but as a feed for cattle. Cattle love silage too. I've written about silage before but since it fascinates me so, please afford me the opportunity to indulge and repeat myself. Silage is feed that is chopped wet and packed to allow for fermentation. Sauerkraut could possibly be considered cabbage silage since it is a wet feed that undergoes fermentation; although sauerkraut rolls off the tongue a lot nicer. There are a plethora of types of silage, but corn and hay silage are by far the most common.
You have, no doubt, seen the many trucks and forage wagons traversing the countryside over the last several weeks delivering chopped corn from the field to the silo. Their cargo is not yet silage and it won't be for several weeks. It is still chopped corn.
Hay silage is made by first mowing the hay and allowing it to wilt in the field for some time to allow the moisture level to reach a critical level. If it gets too dry, it won't pack in the silo correctly and becomes unstable. Instability leads to heating. It could even heat to the point that it burns. If the hay is too wet, the packing process will squeeze out the moisture like wringing out a wet sponge. Along with the water go the nutrients.
Corn silage, on the other hand, is almost always chopped as it stands in the field. The problem with this is that since there is no wilting process, harvesters are at the mercy of the moisture content of the corn plant. When the corn plant dries to about 65 percent moisture, it is ready to chop. If it gets too dry, it doesn't pack well and heats or spoils.
It seems that all of the corn in the county that is destined for corn silage is ready to chop right now. That's why you see some mud on the roads as the trucks and forage wagons hastily exit the fields on their way back to the silo. Farmers are quite busy right now ensuring that all of the beautiful corn turns into beautiful, stable corn silage.
So, what makes the silage "stable," you might be wondering? Stability happens in several steps during the fermentation process. In fact, fermentation, like a fine wine, will continue for years, but stability happens after just a couple of weeks. When the silage has adequate moisture and sugar and is packed so that air cannot get to it, bacteria break down the sugar and produce lactic acid as a byproduct. The lactic acid eventually kills the bacteria that produced it and the plant and its nutrients that remain will not decompose. After about two weeks, stability ensues and the chopped corn becomes silage. If there is inadequate moisture or inadequate packing, oxygen enters the environment producing the opposite of silage: compost.
Since many of the farmers are very busy chopping corn right now, veterinarians who spend a majority of their time working on dairy cattle usually don't have much to do. If this didn't happen every year and we didn't know better, we might feel downright unloved.
But since silo capacity is usually at a premium on many dairies, often the new corn silage must be fed to the cows before it becomes completely stable. This fermenting corn silage can cause bellyaches, indigestion and even twisted stomachs in the cows. Dairy veterinarians feel the love once again when farmers start calling about their sick cows.
I don't know who invented the process of making silage, but it must have been quite a leap of faith to do it the first time. I can imagine that trial and error must have resulted in mostly error and probably a lot of either sick or hungry cows. Today, silage production is very, very high tech. New corn hybrids, powerful choppers and novel storage methods have allowed farmers to improve the quality and quantity of the silage that they harvest for their herds. The cows, I'm certain, appreciate it.