Grass: It’s what’s for dinner

Since the invention of the threshing machine grain has grown in importance for the final stages of beef feeding – often called the finishing program

Since the invention of the threshing machine grain has grown in importance for the final stages of beef feeding – often called the finishing program. If ever there was a time for abandoning this tradition, we might well be there. Eating healthy, eating local, knowing about the farm, high fuel costs, high labor costs, environmental concerns, and disenchantment with industrial agriculture have all contributed to the increased interest in grass finished beef.

But even with all these factors contributing to its popularity, if the consumer doesn’t have a consistently enjoyable eating experience grass fed beef will go the way of the threshing machine.

With that eating experience in mind Jim Gerrish of American Grazing Lands Services, LLC presented his suggestions for finishing beef on grass at the 2007 National Grass Fed Beef Conference. What follows is a summation of his presentation.

The target, by today’s grading standards, is to finish cattle to a grade of USDA High Select or better. To obtain this degree of finish 2 lbs/day of gain is necessary as the animal approaches maturity. This gain is needed for at least the last 60 to 90 days prior to harvest.

In order to achieve that 2 lbs. /day of gain the cattle need at least 65% TDN and 12 % protein. This is more than the NRC nutritional requirements but allows a cushion for the real world environment. Producing that level of protein on pasture is seldom a challenge. Producing that level of energy on pasture is more of a challenge.

Keeping in mind, it’s what the animals actually eat from the pasture that counts, our management must focus on managing a high energy sword. Cool season annuals offer the highest energy, followed by cool season perennials. While warm season annuals can be higher in energy than cool season perennials during certain times in the growing season, their energy level declines significantly as they approach maturity.

Legumes often provide more energy and protein than grasses. However, a pasture containing too high a proportion of legumes can provide too much non-protein nitrogen and hinder animal performance. Pastures with more than 50% legumes are not ideal for finishing. The ‘grassy flavor’ that is sometimes reported in grass finished beef is actually attributable to legumes, not grass.

However, nitrogen from legumes does more for the long term sustainability of pastures than nitrogen from synthetic fertilizers. Therefore, the target for percent legumes in the sword should range between 30 and 50%.

Perennial rye grass is often considered to have the highest energy of all the cool season perennials. The drawback with perennial rye grass is its inability to cope well with summer heat and drought. During these times lower energy grasses with legumes must meet the needs.

As energy levels in grasses tend to decrease, for a number of reasons, pasture management must make the system work. Dry matter intake becomes much more important. This is dependent upon the time spent grazing, how many bites the cows take, and what is in those bites. Higher quality forage from dense pastures reduces rumination time, increases forage intake, and increases the energy efficiency of eating.

Bite size, or the amount of forage consumed in every bite, plays a key role in forage intake. Work at the University of Missouri found that 23% of dry matter intake was explained by pre-grazing pasture mass. 82% of the variation in intake was explained by post grazing residual. Knowing when to take cattle out of a paddock was actually more important than knowing when to turn them in.

A paddock residency period of longer than one day increases the likelihood of mismanagement with reduced pasture and cattle performance. Longer periods of grazing allow cattle to cream off the pasture first and then are left with inferior feed for finishing. This produces a roller coaster nutritional effect and reduces animal performance.

A forage sword consists of layers of plant material with differing nutrient density. Higher in the canopy we find higher energy material – finishing forage. Lower in the canopy we find plant material that will support a brood cow but will depress gain in a fattening steer. Thus we must keep finishing cattle eating only in that higher canopy.

Putting it all together: 1) Grow the highest energy forages that work on your farm; 2) Management of the forages you can grow is more important than trying for the highest energy forage; 3) Maintain high forage intake; and 4) Monitor post feeding residual closely to keep cattle grazing high in the canopy.

Bill Henning is Small Farms Specialist with Cornell Cooperative Extension Service. He can be reached at 315-536-5123. For more information about opportunities for small farms, visit the Cornell Small Farms Program web site at:

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