Nothing lasts forever

After a successful maize harvest, dairy farmers move on to ration formulation with the new feed. However, a precise analysis is required beforehand, providing information on nutrient content, digestibility, and quality of the maize silage. Many dairy farmers take only one silage sample in the first weeks after harvest. The ration is then calculated for 12 months based on this analysis of fresh silage. But is that really correct?

Starch changes its digestibility

Thanks to numerous trials, it is known that the digestibility of starch in maize silage changes during the ensiling process. Over storage time, for example, the protein matrix that surrounds the starch granules in maize partially breaks down. The swelling of starch during ensiling also has a positive effect on starch degradability.
Overall, maize starch then becomes more accessible to rumen microorganisms, and starch breakdown can begin more quickly. Kernel processing (cracking), meaning the crushing of maize kernels during harvesting, also plays a major role. It breaks the outer shell of the kernels, making the starch available in the first place. The maize hull is indigestible, which is why uncracked kernels are fully excreted by the cow.

Starch degradability is therefore higher in spring than before the turn of the year, and it continues to increase with storage time. But how long does it actually take until ruminal starch degradability changes significantly? Results from several trials show that starch digestibility increases most strongly during the first two months of fermentation. After that, changes still occur, but at a much lower intensity.

Foaming slurry – no room for that

Feeding fresh silage can have different consequences. For example, performance losses may occur due to lower digestibility. In addition, more nutrients are excreted unused. They end up in the slurry, where they provide an ideal growth medium for bacteria. The result: foaming slurry. This foam takes up additional storage volume, which is already limited in winter.

Conclusion: Regular evaluation of maize silage is necessary in order to continuously optimize the total ration throughout the year.

By the way: silage additives such as SiloSolve® FC improve the digestibility of maize silage, and live yeasts such as those in orgacell® 5/10 increase digestibility and feed efficiency of silages in the rumen. There is still room for improvement!