Proper packing of bagged silage provides best results

Silage is critical to dairy farm operations. Compared to hay production, silage increases the potential yield of nutrients from available land, decreases feed costs, lowers harvest losses and often increases forage quality. 

However, maximizing the benefits of silage depends on the proper packing of fodder crops stored in airtight conditions to prevent spoilage and increase nutrient value. 

For bagged silage specifically, expert forage consultants in the dairy and cattle industry see benefits to this approach but are united results can only be maximized through well executed feed management – specifically the proper placement and packing of bags. 

“It’s all about good feed management. When packed correctly bagged silage can have a huge impact on profitability, herd health and milk production,” says Bonni Kowalke, fermentation researcher, practitioner and owner of Stem Ag Consulting, LLC., a firm specializing in monitoring and optimizing dairy farm inputs and outputs at all forage production stages.

To help dairy farmers optimize their operations, several consultants and an equipment supplier offer tips on how to properly pack bags, as well as feed management tips to obtain the highest nutrient density silage.

Optimal silage packing equals less spoilage, more nutrients

For many years, Kowalke has maintained her favorite storage system is a bag. 

“The reason I say I love bags is it is the only one storage system which – if packed properly – is a completely sealed vessel,” says Kowalke, adding this is not necessarily the case with bunks, piles or upright silos. 

She adds insufficient packing, which fails to minimize oxygen exposure, can result in spoilage of ensiled forage and lead to feed loss.

“With a bag, one has more control over the spoilage if done properly. It is critical for cow health, milk production, components and profitability to avoid feeding spoiled silage because of all of the negative consequences,” says Kowalke.

Keith Bryan, technical service manager of silage and dairy for the global biosolutions company Novonesis, agrees. Bryan, who holds a PhD in animal science, sums up his company’s approach as advocating for good feed management practices in combination with effective silage inoculants.

“In terms of silage quality at feed out, the number one limiting factor is packing density, specifically suboptimal packing density in a bag,” says Bryan. 

Proper packing of silage can maximize nutrient value of feed.

“Minimizing yeast and mold allows us to preserve more nutrients in the silage. The feed is more nutritious because we are not losing nutrients to those spoilage microorganisms, and we are not introducing contaminants into an animal that we are asking to grow rapidly and efficiently or make large volumes of milk,” says Bryan.

The advantages of bagged silage

The effective use of silage bagging can provide several advantages to dairy farms, including more controlled feedout to maximize nutrient availability and minimize spoilage and loss.

“With large bags, the feedout face is so much smaller and you go through a bag so much quicker than a huge drive over pile or bunker,” says Bryan. 

“So, if packed correctly and by feeding it out more quickly, oxygen penetration is reduced and one can have more hygienic feed in terms of reducing yeast and molds compared to a bunker or a pile,” he adds.

Steve Massie, head of nutrition at Renaissance Nutrition, Inc., also considers the small face at feedout a key advantage to bagging.

“When bunkers become too wide or high, feeders may only use from one-third to one-half of a face, and it can take 48 to 72 hours before they get back to the silage,” says Massie. “By this time, air has gotten into the face, which can result in yeast and mold growth if spores are present, particularly in warmer conditions.” 

He adds very good feed managers will set up the feeding face of a bag so only six to 11 feet are used daily to keep the rest of the silage fresh.

Massie points to another advantage – the ability to select the best, higher-quality forage. He explains most dairy farms have silage that is a little fresher at any given time, a factor which can spur milk production. 

“With a bunker, start at one end and feed the way through. Whatever is there is what the cows get,” says Massie.

Achieving optimal packing density with baggers

To maximize the effectiveness of their equipment, dairy farmers should prioritize packing pressure as a key factor to consider for equipment selection. With proper internal density, oxygen is removed almost instantly and fermentation begins promptly. 

The sealed bags protect silage quality and maintain favorable fermentation conditions even amid unfavorable conditions such as exposure to rain, moisture, excessive dryness or prolonged storage.

Fortunately, as silage bagging has increased in popularity with dairy farms over the years, the equipment has continued to improve. 

Today, the process of creating bagged silage for dairy farmers is relatively simple. Essentially, side unloading wagons pull up alongside the bagger and unload onto the bagger conveyor. End-dump wagons or trucks back into larger table load baggers to unload and start bagging. 

Capacities generally range from two to five tons per minute for side unloading wagons to higher-capacity truck rear-end loading models which handle from four to 16 tons of bagged silage per minute.

To maximize the effectiveness of the equipment, however, dairy farmers need to clearly understand the key factors affecting bagging machine efficiency and capacity. 

At the top of the list is packing pressure, according to Steve Cullen, president of Astoria, and Oregon-based Versa Corporation – global leader in agricultural silage bagging and handling.

“It is important to have a good balance between the pressure caused by the packing rotors and the braking of the bagging machine. The goal is to firmly pack the bag without over-stretching the bag, while gradually moving the machine forward as the bag fills,” says Cullen.

Among silage bagging equipment, packing is approached in various ways. Some systems utilize a cable system with a heavy net backstop, a concept first introduced in North America in 1976. 

After each bag is filled, the cables must be rewound, and the backstop moved to the next location. 

To eliminate the need for external cables, Versa created an innovative cable loop Internal Density System which uses a single adjustable cable inside the bag. The OEM also developed a heavy-duty belt Internal Density System which slides under the bag and pulls it tight lengthwise. 

This facilitates tighter packing of longer silage bags than the industry norm. The largest models, such as Versa’s high-capacity ID1014 bagger, can be used to bag up to 14-foot diameter bags that are 500 feet long.

Although many dairy farmers are at least relatively familiar with bagged silage, those who become informed about which key qualities to consider before purchasing equipment will maximize the health, productivity and profitability of their herds.

Del Williams is a technical writer based in Torrance, Calif.