When it comes to the value of hay in a milk cow ration, Greg Ledbetter is a self-described true believer.

“It's just a whole lot easier to balance a ration around alfalfa hay,” says Ledbetter, who manages two 1,000-cow dairies near Jerome, ID. “Alfalfa hay gives you carbohydrates, protein and digestible fiber. And when the cows chew it, they get some buffering in the rumen.”

Even so, skyrocketing hay prices this year have Ledbetter questioning that core belief. As of late summer, top-quality dairy hay in his area was fetching upwards of $150/ton (delivered) — almost $30/ton more than last year.

To date, he has held the line on the amount of hay he's feeding to his milking cows. Higher milk prices — $4-5/cwt above year-ago levels — have made that call easier.

Bottom line, though, Ledbetter acknowledges that if milk prices head south or hay prices push much higher, he'll have to take a closer look at the amounts of hay he feeds his herd.

“Our philosophy has always been that the market is the market and you pay what you have to,” he says. “But you can only carry that so far before you start looking for ways to hold the line on cost.”

Many other dairymen around the country find themselves making similar calculations. As of early August, hay prices nationally were up by 20% over year-earlier levels. In parts of the West, they were 40% higher.

A major question for many producers: “What can I afford to pay for high-quality hay?”

Answers will vary according to a range of factors — everything from the availability of other fiber/energy sources to the herd's production average. Here are a few concepts to consider as you make a decision:

Effective fiber

Utilizing corn silage or alfalfa haylage as an alternative source of fiber and energy in the ration can minimize the sting of rising hay prices. Particle length is the key to making these silage-based rations work. Wisconsin extension dairy nutrition specialist Randy Shaver recommends having your nutrition consultant run a forage sample through a Penn State forage particle separator to determine fiber needs.

Calculations can get tricky, Shaver warns. For example, the particle separator results might show that you need 2.5 lbs of hay/cow to ensure proper rumen function.

“But you have to figure that cows will sort some feed or the TMR mixer might grind the hay too fine. So you'd probably want to bump that up to 4 or 5 lbs of hay,” he says.

A key point on hay costs: If you need the hay to ensure proper rumen scratch, price becomes a secondary issue.

“It's just like gasoline prices,” says Illinois extension dairy specialist Mike Hutjens. “I might not like paying $1.60 or $1.70 per gallon. But my car isn't going to run without it, so I pay. If I don't provide that cow with effective fiber, she's not going to run, either.”

Local markets

Keeping close tabs on prices at local tested-hay markets over several weeks will give you a good starting point for determining the value of hay in your area.

As you collect information, start breaking prices down by point of relative feed value (RFV). For example, if hay with a 150 RFV consistently fetches $105/ton on local markets, each point of RFV is worth 70¢. You can use those numbers as benchmarks for working with hay sellers.

Two general guidelines:

  1. Aim for hay that's 85-90% dry matter. Why pay for water?

  2. For milk cows, buy hay with an RFV in the 130-175 range.

“If you go much higher than that, the hay is probably too rich and a ruminant really won't be able too make use of it,” says Charlie Stallings, Virginia extension dairy nutrition specialist.

Nutrient value

The idea here is to develop a least-cost ration by breaking hay down into essential components — protein, energy, fat, fiber, phosphorous and calcium. Then calculate the worth of each nutrient and compare cost to other individual feedstuffs.

In a typical Midwestern ration, for example, you could use soybean prices to calculate the cost of protein, shelled corn for energy, tallow for fat, dicalcium phosphate for phosphorus and limestone for calcium.

You can do the calculations by hand or utilize computer software like commercially available shadow-price programs, the University of Wisconsin's Feed-Val or Ohio State's Sesame.

One rub: “Spreadsheets tend to ignore effective fiber and undervalue hay,” says Shaver.

Milk prices

As milk prices head upward, hay in the ration becomes increasingly more valuable. Mike Hutjens figures each pound of hay strategically placed in the ration is worth a pound of milk.

“So if the milk price is $16/cwt, you can make a pretty strong case that good-quality hay is worth somewhere around $320/ton (2,000 lbs at 16¢/lb),” he says.

When the milk price drops to $12/cwt, the same hay is worth considerably less.