Six ways to help avoid the ‘silage slump’

Cattle operations commonly experience a decrease in production and performance when they open a new corn silage upright silo, bunker or pile. This phenomenon is known as the “silage slump.” 

Ensuring the quality of forage fed is an important component to maximizing production, controlling cost and maintaining herd health. New silage slump can hurt these goals. A few best practices for harvesting, storing and feeding silage can help prevent these problems.

1. It is important to ensure proper whole-plant moisture levels when harvesting. If you’re using bunkers and drive-over piles, whole-plant moisture should be 66% to 68%. For vertical structures, aim for 63% to 66% moisture. Regardless of storage method, proper moisture is one of the most important things to remember when harvesting corn silage.

2. Monitor kernel processing and chop length. Kernel-processed corn silage should have a theoretical length between ¾ and 1 inch. Set the spacing on the kernel processors to 1 millimeter. Processing corn silage this way increases the amount of fiber fed because it decreases the sorting of corn cob “hockey pucks” by cows and enables better digestion of the starch in the corn kernel.

3. Pack bunkers carefully. Bunker silos should be packed constantly while filling. The blade tractor operator should ensure that the layer is being packed thinly, no thicker than 6 inches, and that the blade does not interfere with layers that have already been packed. Packing in 4-inch to 6-inch layers increases silage density, reduces oxygen infiltration and subsequent spoilage, and increases storage efficiency.

4. Cover silage well. After the silage is packed, cover it as soon as possible, ideally with 6- to 8-mil plastic. Use a secondary oxygen barrier and secure it. It is common to use a second layer of clear plastic that effectively obstructs air flow into the silage. This works great, though you should cover the oxygen barrier with regular plastic to prevent sunlight deterioration. Using this combination approach stops much of the spoilage of corn silage and haylage at the top of the pile. In addition to preventing spoilage loss, this also lessens the need for workers to pitch off spoiled silage, which saves time and reduces risk.

5. Be sure to give silage time to ensile. Ideally, cattle producers should allow silage to ensile for at least four months before feeding. As silage spends additional weeks in storage, the starch becomes more digestible and helps avoid the silage slump. When you do begin feeding from the new silage supply, monitor quality in the first few feet. Many bunkers and corn silage pile have sloped ends, which means silage in the front is not packed as densely as silage deeper in the bunk. This looser packing makes growth of undesirable microbes more likely. Aim to maintain a well-managed face that is vertical or perhaps slightly obtuse and smooth. If there are differences among fermentation, moisture, pH or other characteristics of the silage as the depth into the bunk increases, consider cutting across pile ends and blending multiple depths of silage together, such as silage from 2-, 4-, and 8-foot depths. This can minimize the negative effects of silage slump by diluting potential mycotoxins and reducing the moisture and nutrient variation among silage from different levels.

6. Make efforts to deliver a consistent diet. It’s critical to feed pens as close to the same time every day so dry matter intake stays as consistent as possible. Try to feed within 20 minutes of the previous days’ time. Cows crave consistency. Much like humans, these animals need a structured routine for activities as well as specific nutrition to maximize performance, health and overall well-being.