Uniform bales and plenty of plastic. Those are two keys to making high-quality square-bale silage with an in-line wrapper, says Tim Pitzen, Cuba City, WI.

He's a custom baler and wrapper, and also makes bale silage on a 60-cow dairy farm he runs with his father, Gerald. He likes in-line wrapping because it's faster and uses less plastic than wrapping individual bales.

“The only complaint I get from clients is that it takes more space because individually wrapped bales can be stacked,” says Pitzen.

He puts bales into the machine sideways, so uniform length is critical. If they're too long, they won't fit into the wrapper. And short bales don't get wrapped tightly on the ends, leaving air pockets.

“They all have to be 6' long, give or take an inch,” he says. “That's one of the downfalls.”

While University of Wisconsin recommendations say silage bales should get six to eight layers of 1-mil plastic, Pitzen says that's not enough for square bales.

“I honestly don't know how you can do it with six or eight wraps,” says Pitzen. “I'm putting on a minimum of 14 wraps, and I use pretty good plastic.”

Sharp stems on bale edges and corners can poke holes if the plastic isn't thick enough. Also, thick plastic around the entire bale prevents sunlight from causing oxidation and spoilage, he says.

Make the bales as tight as possible, and wrap them immediately, he advises. “If you let them sit, they get sloppy.”

He's made silage at up to 50% moisture, but bales that wet are difficult to make and handle. And he prefers to feed drier silage to his cows. “I've had some in the low 30s, and it was beautiful feed.”

Kevin Shinners, University of Wisconsin ag engineer, also is impressed with low-moisture bale silage — and with in-line wrapping.

“It works well. I think it's a really good way to do it,” he says.

In a side-by-side test, he line-wrapped big round and big square bales of alfalfa from the same field. Hay was baled at 30-40% moisture.

“We found no difference in the amount of dry matter loss between round- and square-bale wrapping,” Shinners reports.

Dry matter loss during five to 12 months of storage was just under 5% for both types of bales.

The bales were wrapped with eight or nine plastic layers, and Shinners doubts that more plastic would have kept stems from poking holes. He mended holes with a high-quality tape made for that purpose.

“We did have a couple of problems where the tear occurred down at the bottom of the bale, where we couldn't see it,” he says.

Because of their shape, square bales require more plastic per ton of hay and more space than round ones. Wrapping two-high stacks would conserve both, but Shinners cautions against it.

If the top bales aren't placed perfectly on top of the bottom ones, the plastic won't follow the contour, and air channels will remain after wrapping.

“If you get a hole right at that location, for whatever reason, you could get oxygen up and down the whole line of bales and a lot of spoilage,” he says. “There are people doing it, but I think the risk outweighs the benefit.”