What to Consider When Cutting Two Stage Crops for Silage

Annual crop emergence this spring was spotty with some parts of the field not germinating until the June rains. For plants that did grow shortly after seeding, a second flush of tillers developed after the rains.

This created a crop with two different growth stages in the same field. The early growth is filling, and the late growth is at the heading to flowering stage. The question is, when is the best time to cut it for silage?

Quality of forages decline as they mature. Protein content decreases. Acid detergent fibre and neutral detergent fibre increase which reduces free choice intake. Energy content in the silage remains relatively constant. Energy in the straw decreases as it matures, but this loss is offset by the increasing amount of energy (starch) in the seed head. There is no advantage having fully mature grain and straw going into the pit, pile, or round bale silage. Cut the crop when the more mature plants are at the correct stage for making silage.

Plants at different stages of maturity contain different amounts of water. The younger the plant, the higher the moisture content. Cereals are in the mid to late dough stage, contain approximately 65 to 70% moisture. Younger plants can be approximately 80% moisture. Waiting for the young plants to develop results in the older plants being over mature. Final moisture could be low, and the chopped silage is harder to pack.

It is tempting to cut the crop as close to the ground to maximize yield, but this can reduce quality. The bottom three to four inches of stem is the lowest quality part of the plant. In drought conditions, it also contains the highest concentration of nitrates. Soil kicked into the windrow by the swather, chopper, or baler pickup can result in white mould developing in the forage. Adjust equipment so this does not occur.

Sampling and testing the silage is recommended. With shorter crops, the grain to forage ratio will be higher than in a normal growing season. Protein and energy could be higher than usual.

For additional information on when to cut silage, contact Barry at 403-741-6032 or bjyaremcio@gmail.com.