What Dairy and Beef Producers Should Watch in Their Silage Ration

Removing Guesswork from Feed Buying

Taking a Silage Sample 

It's never a good idea to walk up to the face of a bunker silo and take a sample, mainly for two reasons. First, it’s not safe and you could be seriously injured or even killed. Second, it doesn’t provide a good sample due to forage variation within the silo. Peel down the face like you normally would for daily feeding, and take at least five double-handful samples from across the silage you pulled down. Then put those in a large bucket or tub and remix, then fill up at least a quart sample bag from that composite and send it to your laboratory. Corn silage can be difficult to sample due to the variation in particle size and density between kernels and fiber, so it’s important to take a large enough sample.

Dairy Ration Analysis

Of key importance to dairy nutritionists in corn silage analysis are dry matter, neutral detergent fiber (NDF) and starch. Dry matter analysis can be done on the farm using either a microwave, Koster Moisture Tester or a portable NIR (near infrared) device. Dry matter testing is typically done at least weekly, or any time the feeder perceives that the dry matter content is changing. Feeding consistent proportions of dry matter in the ration is critical. If corn silage is wetter, feed more to get the same amount of dry matter; and if the forage is drier, feed less to get the same amount of dry matter.

The highest variation is seen in NDF and starch content. Some of that variation is real variation, but there are also sampling and analytical errors that can occur. Because of this, many nutritionists have begun reformulating rations on a three-week rolling average of analyses rather than one single sample result. If corn silage is lower in NDF and higher in starch, the nutritionist will recommend a ration with less corn grain. If it's higher in NDF and lower in starch, then they'll bring in more corn grain to maintain the consistency of the total mixed ration.

Beef Silage Ration Dependent on Management System

On the beef side, taking silage samples in each field where there’s a different hybrid or type of management. An example would be manure applications in some fields but not in others. Beef producer feed-out depends on their system and whether they're feeding growing calves, which requires similar management to dairy with a focus on quality. Taking samples upfront can offer an idea of dry matter content prior to ensiling.  Moisture at harvest should be between 60% to 70%.

When selecting a silage hybrid, the easy option is to pick a hybrid with the highest grain production, but yield by itself is not the best indicator of silage quality. Particle size is also a factor to watch. The standard range is ⅜" to ¾". If the cut is too fine, seepage could occur. If it's too coarse, it won't pack as well and poor fermentation may result.

Article is out of Dairy Herd Management, September 2017.

Tags: Feeding Strategies, Rations, Silage