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Grain vs. grass finishing: Tracing the end results

Gustavo Cruz Published on 24 July 2012

Currently, the U.S. is the world’s largest beef producer, representing approximately 21 percent of the world’s beef production – but it’s the fourth-leading country in world beef exports, behind Brazil, Australia and India.

Figure 1: Carcass equivalent production per country, in metric kilotons

In the last 20 years, the trend in beef consumption by Americans has changed significantly: In 1985, the amount of beef consumed per capita was 80 pounds per year and beef represented 57 percent of the total meat purchased in a supermarket; today the consumption has dropped to 60 pounds per year and beef represents 45 percent of the total meat purchased.

This drastic decline in consumption has been followed by an increase in the annual expenditure in beef from U.S. $170 (1985) to U.S. $270 (2010).

Grass-finished beef represents approximately 3 percent of the total U.S. beef market; it is a small but ascending market.

Its success is going to depend upon producers, biology of the animals and consumer acceptability. The producers first need to be open to new methods (nutritional, management or genetics) that can assist them to improve profitability; this “multigenerational resistance” has led to decrease in income which consequently leads to less interest of the young generation to continue the enterprise.

Today the average American farmer is 58 years old; in 1980 the average age was 50. Only a few producers really know how to manage grass and this lack of knowledge can lead to poor-quality outputs.

There is a big difference between grass-finished and grass-fed beef – the former is a product that contains characteristics (marbling, juiciness, tenderness and flavor) that will be well accepted by consumers.

Figure 2: Beef consumption as percentage of beef purchased in relation to the other meats and total dollars expended in beef per capita

In the U.S., beef cattle have been genetically selected for high caloric diets and confinement situations; the same type of animal that performs well under a feedlot situation does not necessarily perform well in pasture, so producers need to choose the right genetics for their production settings.

Lastly, consumer acceptability and willingness to pay more for the product are important elements to collaborate with the progress of grass-finished beef market.

A collaborative research study between the Department of Animal Science at University of California – Davis and Yolo Land and Cattle company brought some new insights on understanding biological differences between grass-finished and grain-finished animals.

The objectives of this study, conducted by myself and Drs. James Fadel and Heidi Rossow, were to compare the characteristics of marbling distribution and its association with meat traits, as well as performance and production.

The study had a total of 32 Angus steers (916 pounds) that were divided into two treatments (grass-finished or grain-finished). The pasture was composed of a mix of clover and ryegrass and the feedlot diet contained 80 percent of cracked corn.

Some of the traditional (“not surprising”) results were that feedlot steers grew faster (2.97 pounds vs. 1.59 pounds per day), required less time on feed (167 days vs. 281 days), presented heavier carcass weights (893 pounds vs. 785 pounds) and had higher dressing percentage (63 percent vs. 58 percent).

In addition, feedlot steers’ carcasses had higher yield grade (3.6 vs. 2.9), kidney, pelvic and heart fat (KPH, 2.8 percent vs. 1.7 percent) and quality grade (low Choice vs. high Select).

Interestingly, the percentage of boneless, closely trimmed retail cut (BCTRC percentage), a measure of high-value cuts of the carcass, was similar for both treatments (48 percent); this similarity can be explained by the high amount of “waste fat” (KPH, subcutaneous, intermuscular fat) in feedlot carcass.

Also the retail yield (BCTRC x carcass weight) for both treatments were similar (400 pounds), which means that grass and grain steers produced similar amounts of high-value cuts of meat, such as round, loin, rib and chuck.

In this study, the authors did not find any difference in shear force (tenderness measure) or cooking loss (water loss) between the two treatments.

Figure 3: Fat cell size distribution for grain-finished and grass-finished cattle

A consumer taste panel with eight panelists was used to judge meat characteristics between grass-finished and grain-finished beef.

The only trait that was significantly different was tenderness – the judges scored the grass-finished beef as more tender than the grain-finished beef – the other traits, such as juiciness, flavor intensity and flavor quality were not different.

In terms of profitability, the grain-finished system had a higher net return than the grass ($38 vs. $4 per head), even with grass beef receiving a 15 percent premium.

In order for the grass-finished system to obtain a similar net profit as the grain, the producer should shorten the time of pasture by one month or ask for at least an 18 percent premium on the carcass.

Now, some of the non-traditional (“surprising”) results – but before that, a simple review on fat cell growth.

Fat cells can grow mainly in two ways: hyperplasia (number) and hypertrophy (size). Because of the two types of growth mechanisms, the fat tissue normally contains two populations of fat cells – one is the small and the other is the large.

The proportion of these two types of fat cells (small or large) varies with sex, breed, age, genetics and nutrition.

In this study, the grain-finished animals had larger marbling fat cells but they represented 82 percent of the total fat cells; on the other hand, the grass-finished animals had smaller marbling fat cells and they represented 92 percent.

The authors tested correlations between size and number of fat cells with meat and carcass traits and concluded that the size of the fat cells is correlated with quality grade and tenderness – and that the proportion of the small fat cells was correlated with juiciness and palatability.

The take-home message is that grass-finished and grain-finished beef do not compete for the same market; current beef cattle genetics does not favor grass-finished producers; the biology of fat cells helps grain-finished carcass to have higher quality grade and grass-finished enterprise can be profitable and produce good-quality meat.

And remember: Grass-finished beef producers = Grass producers.  end_mark

Gustavo Cruz is a post doctoral scholar at the Department of Animal Science for UC – Davis. Contact him at (530) 752-2401.

References omitted due to space but are available upon request. Click here to email an editor.

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