Benefits of maize silage for animals
Corn silage is used for feeding all dairy cattle on the farm: growing animals, dry cows, and lactating cows. It must be supplemented with protein, minerals, and sometimes energy to meet the animal's nutrient requirements. Corn silage feeding strategies vary depending on animal age, level of production, and physiological status as well as the other forages being fed, if any. Because of its high grain content, feeding strategy for corn silage fed to high producing cows differs from most other forages. Corn silage quality factors that are important to consider when balancing rations are energy content, NDF content, NDF digestibility, length of cut, starch content, and starch digestibility.
Corn silage is an excellent dry cow forage as it is palatable and can be limit fed or mixed with lower energy forages. However, the amount of corn silage fed to dry cows and heifers must be restricted due to its high energy content. Fat cows should receive rations of lower energy density than thin cows. Feeding unrestricted quantities of corn silage throughout the dry period will result in fat cows which tend to have lower dry matter intakes and higher incidence of metabolic problems such as ketosis and fatty liver following calving. Corn silage contains low calcium compared to other forages. This is an advantage because high calcium intake in the dry period contributes to milk fever following calving.
The high energy requirements of lactating dairy cows increase the difficulty of balancing rations that meet animal needs for both energy and fiber. The effectiveness of corn silage fiber at stimulating rumen movements and chewing is primarily determined by its length of cut. Coarsely chopped corn silage will stimulate more chewing and salivation per pound of fiber than feeding the same silage that has been finely chopped. If fiber is more effective at stimulating chewing and salivation, less is needed in the ration to provide the same amount of buffering from saliva. Although coarsely chopped corn silage is more effective at stimulating chewing it will not pack as densely in the silo, will have fewer corn kernel coats broken, and will have larger pieces of cob which will allow sorting and possibly refusal by cows than more finely chopped corn silage. Length of cut should be adjusted to provide larger silage particles while minimizing the number of large cob particles and unbroken corn kernels. Wetter corn forage can be chopped coarser than drier corn forage.
Dry corn kernels require a finer chop to break seed coats than wetter corn kernels. Kernel breakage will maximize starch digestibility. In addition, wet corn forage chops more consistently than drier corn forage. The chopper knives shred dry leaves rather than cut, decreasing the uniformity of particle size and allowing animals to sort further.