Forage Quality Grazing and Hay

Quality forage for beef cattle is becoming more important as stocking rates increase and the cost of production inputs -- e.g., such as land, fertilizer, and seed continue to rise.

Quality forage is forage that contains a high percentage of total digestible nutrients (TDN) and is readily consumed. It must have a high percentage of protein, low percentage of fiber, high leaf-to-stem ratio, and high energy potential. All producers and purchasers of forages should recognize the value of quality grasses, legumes, and hay. It costs very little more to produce quality grazing and hay than it does to produce fair or poor quality hay.

Factors Affecting Quality

Many factors affect the quality of a forage, but four that you can control are 1) the stage of growth when plant is grazed or harvested; 2) the time of year the forage is grown; 3) the fertility content of the soil; and 4) the nature of the plant species.

Stage of growth -- All forage plants are higher in quality when young than when mature. Grass leaves mature from the tip downward. Also, the cell walls are thinner when young, which means higher digestibility. Young plants usually contain more nitrogen, resulting in an increased protein content. The stages of grass growth include:

Vegetative -- from seedling stage to boot stage.

 

Boot stage -- seed head has not emerged but has begun to swell the top of the plant.

 

Head -- head has emerged but plant has not flowered.

 

Flower -- head has flowered and pollen is being distributed.

 

Mature -- the flower has developed into seed and the plant has reached maximum maturity.

These are the growth stages of an annual legume (e.g., crimson clover):

Perennial clovers act differently, since they continue to produce vegetative growth during flowering.

Even though you usually get maximum yields when the plant approaches maturity, much of the quality has been lost. Some sacrifice in total yield will result in higher quality forage, which gives more beef or milk production per acre of forage. To get maximum energy and protein per acre, you should graze grass before seed head formation or harvest for hay in the boot stage. You should harvest legumes in the bud to early bloom stage.

Time of year -- Summer grasses lose quality as the season progresses, even though you harvest the forage in the proper growth stage. This loss of quality in late summer is caused by shorter days, higher temperatures, and lower available soil moisture content. Therefore, the first hay clipping or first few weeks of early summer grazing is higher in quality than the rest of the season.

If you need high quality hay, store the first growth of all summer grasses.

Fertility content of the soil -- The amount of available plant food, especially nitrogen, determines the yield and, to some extent, the quality of a forage. Since crude protein content of a forage is determined by multiplying the percent nitrogen by 6.25, the amount of nitrogen in the plant tissue determines the protein content. Research has shown that nitrogen fertilization also increases the animal preference for the forage, the amount consumed, and to some extent, the digestibility.

Nature of the plant species -- Grasses are normally lower in quality than legumes, and within each group there is a wide range of quality. Assuming grasses and legumes are harvested at the proper stage of growth, legumes are usually higher in protein, higher in digestibility, and result in increased intake.

Grasses also vary in quality. Normally, cool-season grasses are higher in quality than warm-season grasses, and annuals have higher quality than perennials.

To keep a forage, especially a grass, at a good quality, you will need to control grazing. This is best done by cross-fencing and rotational grazing. Ideally, three pastures per herd are needed, and the pastures should be small enough to allow a grazing pressure of about three cows per acre. Hybrid bermudagrass will require up to five cows per acre. Example: Assume common bermudagrass or bahiagrass, 100 acres, 50 cows. For maximum forage quality and use, you need a grazing pressure of three cows per acre. Therefore, the pasture size should be

Rotational grazing based on these assumptions will involve moving the cattle from one pasture to another every 7 to 14 days, depending on moisture, fertilizer, and other factors. Surplus forage can often be produced on one pasture to be harvested for hay. Rotational grazing to increase quality and reduce forage loss can increase production by 30 percent without additional fertilizer.

Harvesting for Hay

Here are some general recommendations to help increase the quality of hay:

• Harvest at the recommended stage of growth. Do not let the forage get too mature.
• Fertilize to produce the yields and quality desired. A soil test analysis will help to determine the amount. (When the whole plant is harvested, potash removal is about doubled.)
• Control weeds, especially in early season.
• Use a conditioner to crush stems of plants to allow faster drying.
• Use a tedder or rake to move hay that has been rained on before baling.
• Bale when forage moisture content is reduced to about 18 percent.

Hay quality is mainly determined when it is cut. Hay can only decrease, not increase, in quality with age.

By Lamar Kimbrough, Ph.D., Extension Agronomist--Forages

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Information Sheet 1012
Extension Service of Mississippi State University, cooperating with U.S. Department of Agriculture. Published in furtherance of Acts of Congress, May 8 and June 30, 1914. Ronald A. Brown, Director

Copyright by Mississippi State University. All rights reserved.

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