Mowing, Wilting and Baling Hay Crops

Harvest timing.

No single factor affects the quality of hay or silage as much as the maturity of the forage when the mower is first pulled into the field (Table 2). As plants mature, stem is increased in the total forage mass, and therefore, the leaf-to-stem ratio is reduced. Increased proportions of stem usually result in higher concentrations of fiber (usually measured as NDF and ADF) and lower concentrations of CP and digestible DM. Unfortunately, the management of forage crops is complicated by the need to allow adequate initial growth, and either adequate regrowth or harvest intervals (depending on the crop) to maintain plant vigor and the health of the stand. Clearly, these competing management concerns require some compromise.

Table 2 Effects of maturity on forage quality

Nutrient Requirements of Dairy Cattle (1989).

For alfalfa, the general rule of thumb is to harvest before the crop reaches 1/10 bloom; however, the quality characteristics of alfalfa harvested at this growth stage may not allow producers to sell to top-dollar dairy markets. Bermudagrass should generally be harvested in intervals of about four weeks during the growing season. Individuals wishing to market or feed bermudagrass hay of the highest quality may reduce this interval by a few days, but haying intervals of less than 22 days are very rare. Tall fescue and other cool-season perennial forages should be harvested at the boot or early heading stages of growth. The interrelationships between maturity, concentrations of fiber (NDF) and digestibility for tall fescue are shown in Figure 1. The most rapid changes in fiber content and digestibility occur between the late boot and early bloom stages of growth. Weather permitting, producers should make every effort to harvest these crops at the best compromise between nutritive value and yield. The ideal harvest maturities for various forage crops are summarized in Table 3.

Figure 1. Digestibility and neutral detergent fiber (NDF) in Kentucky-31 tall fescue at various maturities.

Source: C. S. Hoveland and N. S. Hill, University of Georgia.

Table 3. Recommended growth stages or time intervals to harvest various hay crops1.



First cutting: bud stage

Second and later cuttings: 1/10 bloom

First cutting following spring seeding: mid to full bloom

Orchardgrass, timothy or tall fescue

First cutting: boot to early heading

Regrowth: four- to six-week intervals

Red, arrowleaf or crimson clovers

Early Bloom

Sericea lespedeza

15 to 18 inches

Oats, barley, rye, ryegrass or wheat

Boot to early heading (nutritive value of rye will deteriorate much faster than

other cereal grains after this growth stage is reached)

Annual lespedeza

Early bloom and before bottom leaves begin to fall off

Ladino or white clover

Cut at correct stage for companion grass

Hybrid bermudagrass

First cutting: 15 to 18 inches

Second and later cuttings: every four to five weeks (intervals down to 22 days can be used for highest quality)

Birdsfoot trefoil

Cut at correct stage for companion grass

Sudangrass, sorghum-sudangrass and pearl millet

30 to 40 inches