Fescue hay quality climbs to the top of the peak about the time that first head pokes up and after that it's headed down hill in one heck of a hurry. From the time fescue begins to head until green seed forms, you're losing about one-half of a percent of protein every day, explains Kansas State University Agronomist Gary Kilgore.

That's roughly a three-week period so you're looking at a drop from about 16 percent to about 6 percent. And even though Mother Nature usually does her best to keep the baler parked at the edge of the field, Kilgore notes that 12 percent hay is very attainable most years, although many producers allow the grass to fully mature, thinking they're getting more quantity even if they are giving up some quality. Whether it's brome or fescue, he says, about a week after heading is a pretty good compromise. At that point, quality is still fairly high and lion's share of the dry matter that's ever going to be there is there for the taking. You'll probably get about 80 percent of the dry matter at that point Kilgore says, but you'll be getting virtually all of the leaves and stem. You'll also get better production later because it's better for the grass to cut at that time rather than waiting until it's mature.

Brome quality doesn't fade quite as quickly as that of fescue. Generally a seven to 10-day delay after June 1 can result in a 1% protein loss, approximately a 3% drop in quality after a 30-day delay, according to Butler County Extension Agriculture Agent Dave Kehler. Kehler also points out that there is an indirect cost to delaying hay harvest. The stress on the brome and the resulting increase in weeds leads to an eventual decrease in forage production. Depending on the class of cattle being fed, the big loss may come when that delayed-harvest hay is fed, he says. If the hay doesn't meet the cattle's nutritional requirements, having to replace that lost protein sheds some light on the true value of hay.

Kehler outlines the cost supplement needed to replace protein lost in delayed-harvest hay. In his analysis, having to make up for just a 3% protein loss with $145/ton 20% cubes makes value of that lost protein about $21.75 per ton of hay.

Prairie hay is quite a bit more forgiving when it comes to delayed harvest. At heading, protein content will be at about 7 percent and by mid-July it will probably be in the 5-5.5 range. In early September, however, it will likely still be about 4% protein. Timely harvest is important for any type of forage, Kilgore stresses, but it is particularly important for tall fescue. If this spring's frequent rains have kept you out of the hay field so far, however, he says you still have a shot at putting up some high quality fescue hay.

Some of the best grass hay we can put up in this area is in the fall, he explains. The soluble sugars in cool season grass in the fall are converted to starch very slowly and the result is very, very palatable hay. Fescue hay put up somewhere in the October 10 to 20 range can be easily up around 10-12 percent protein.