Lactic acid is one of the acids formed during preservation. Lactic acid is a palatable acid, and a properly conducted preservation process is characterized by a fairly high proportion of lactic acid. Lactic acid, and indirectly the pH, can be influenced by harvesting a crop that is not too dry, but rich in sugar.
Ideally, grass silage should have around 5% lactic acid. Lactic acid has a positive effect on the milk yield; in the rumen, it is converted into propionic acid, which is then converted into lactose.
Wet silage can contain a lot of lactic acid: 12-15% is common. Although lactic acid is quite palatable and has a stimulating effect on the milk production, too much is not good, either. Often, particularly acidic silage puts feed intake under pressure. In these cases, rumen acidification may also occur, especially if the cows feed irregularly. It is then important to use additional raw materials in the ration that ferment gently and to include sufficient buffering material in the ration.
Fertilizing silage with too much nitrogen can also have a negative impact on the stability of the silage. After all, proteins are fuels for negative bacteria and large amounts of nitrogen have a buffering effect. Acidification is slower and preservation is less successful.