1. Flavie AUDOIN, pre-optional internship ESP, from 06/05/2013 to 08/31/2013
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COMPARISON OF MEAT TENDERNESS BETWEEN NORTHERN EUROPEAN TYPE CROSSBRED CATTLE
(FROM NORTHERN EUROPE) AND CRIOLLO CATTLE (FROM NORTH AFRICA AND SPAIN) USING THE
WARNER-BRATZLER SHEAR FORCE.
1. Seeking a breed of cattle adapted to drought.
For the past fifteen years, drought has strongly affected parts of Arizona. New Mexico, and Texas
in the southwestern United States; and Sonora, and Chihuahua in northern Mexico. This cross
border region can best be described arid to semi-arid, with annual precipitation of less than 16
inches. So, it is necessary that ranchers choose cattle breeds adapted to this kind of climate in order
to maximize the feed resources present in the landscape without degrading them. During the early
summer, the predominant feed is the « mesquite », a legume rich in protein. The Criollo breed,
originally from North Africa and Spain, and naturalized throughout the Americas for the past 500
years, is a cow which seems to be better adapted to the drought conditions currently affecting the
region. Indeed, thanks to her smaller size and as a consequence, lighter weight, than the British
breeds such as Hereford and Angus, the Criollo has less impact on the sometimes fragile soils found
in the region. She moves farther to eat; eats fewer hours per day; and drinks less water; so the
pressure on the land is less. She is more active in high temperatures and finally, she calves more
easily (Darrell J.P., 2007; Price D.K. and al., 2013). In spite of her numerous advantages, this breed
is rare in the landscape because she is criticised for being less productive than the other breeds
because the reaching of an acceptable slaughter weight is delayed. However, she is famous for her
great meat quality with especially great marbling (factor of 10% of the tenderness); criterion of
tenderness guarantee chosen by the customers (Price D.K. and al., 2013). In December 2012, the
United States Department of Agriculture (USDA) set up tenderness standards for the marketing of
the meat using the Warner-Bratzler Shear Force test (WBSF). So, we are examining whether,
according to the USDA standards, and with the WBSF test, the meat from the Criollo breed is more
tender than the conventional crossbred cattle who originated in northern Europe.
2. An experiment on twelve steers of two different breeds in partnership with the Food
Products and Safety Laboratory of the University of Arizona.
The experiment focused on the WBSF test was completed on 12 steers who were on average 30
months old. Of the 12 steers tested, 8 are Criollo and 4 are crossbreed (combination of 9 breeds)
from a ranch in southern Arizona with 250 head of mother cows and 32,000 acres. This experiment
was conducted from the 19th of May 2013 to the 7th of October 2013. The live weight of the
Criollo steers is between 800 pounds and 1,000 pounds. For the crossbred cattle, it is between 1,000
pounds and 1,200 pounds. Even if the Criollo are lighter than other breeds, their carcass generally
meets or exceeds that of the crossbred steers. This is occurring despite the fact that the resources of
the ranching operation requires finishing the cattle on rangeland pasture because there is no
supplementation of feed.
Before cutting, the meat was aged for 3 to 4 weeks in a cold room. The WBSF test is realized the
same day or the following day. The Warner-Bratzler machine can measure the pressure required
(pounds/cm²) to cut a piece of meat. The lower the shear force, the more tender the meat is.
The meat which is analyzed is a ribeye of 10 ounces cut from between the 12th
and the 13th
rib.

2. Flavie AUDOIN, pre-optional internship ESP, from 06/05/2013 to 08/31/2013
2
There are two different protocols for the use of this tool. We use the one where the meat is cooked
and cooled to the room temperature the same day (Wheeler T.L. and al., 2005). First, we cook the
meat with an electric grill for 12 minutes to reach the required internal temperature of 160°F.
Before taking the cores, we let the meat cool to the room temperature of 70°F. The temperature is
checked by an electric thermometer. On each animal, we removed 8 cores with a diameter of 0.5
inch and 0.75 inch length perpendicularly to the muscle using a hand coring device. It is necessary
that these samples are consistent and they are not taken on a nerve or tendon as this may distort the
results. According to the protocol, we must take a minimum of 6 and a maximum of 8. We decide
to take 8 to get a better sampling (Wheeler T.L. and al., 2005; Bruns K.W. and al., 2000). For each
animal, then, we use the Warner-Bratzler machine to measure the tenderness by cutting the samples
in half. Reading the shearing force is direct.
3. Remarquable and surprising results of meat tenderness.
According to the USDA, the Agricultural Marketing Service and the American Society for Testing
and Materials International tenderness standards, the meat is define as « tender » for a shear force
included between 8.6 et 9.7 pounds/cm² of pressure and « very tender » for a shear force inferior to
8.6 pounds/cm² (Halladay K., 2013).
The statistical analysis is about the comparison of the WBSF test averages for each animal
depending on the breed. According to the Bartlett test (p-value = 0.03292), variances are not
homogeneous. Furthermore, the series are not paired. So, we use the Kruskall-Wallis test. We
obtain a p-value of 0.4399. (Chart 1, Figure 1) The differences of tenderness between the two
breeds are not significant. All of the shear forces are inferiors to 8.6 pounds/cm²; so, the meat is
very tender for all of the animals.
However, visually, the Criollo meat has significantly more marbling than the crossbred meat.
Breed
WBSF test
average for
each animal+
(pounds/cm²)
Average for
the sample
(pounds/cm²)
Standard
deviation
(pounds/
cm²)
Criollo
4.1
5.96 1.31
5.1
6.25
5.8
5.3
8.5
5.8
6.8
Crossbred
5.8
5.58 0.32
5.7
5.1
5.7
Figure 1: Comparison of the WBSF test averages
depending on the breed
(Kruskal-Wallis Test, 2013)
Kruskal-Wallis test:
*** : p<0,001 / ** : p<0,01 / *: p<0,05 / ns : not significant
+
8 measures per animal

3. Flavie AUDOIN, pre-optional internship ESP, from 06/05/2013 to 08/31/2013
3
4. A difference of tenderness not significant between the two breeds which cannot be
generalized due to the low sample.
The results show that there is no significant difference for the tenderness between the two breeds.
As a consequence, the Criollo meat is not more tender than the crossbred meat.
In order to increase the representativeness of the study, it could be important to have a higher
sampling of individuals with the same number of animals for each breed. For a future study, it could
be interesting to compare the meat tenderness between different ranches and farming practices as
well because this may certainly be influenced by these elements. In spite of the direct good
feedback from the customers at the farmers markets, a tasting centered in the tenderness and the
sensory quality by a professional panel of judges could also expand this study.
The meat tenderness is multifactorial because it depends on the feed, the age, the breed, the calcium
rate, the stress before and during the slaughter and the protein input (Price D.K. and al., 2013). It
should be noted that none of these elements have been taken into account in this study.
The immediate perspective for the ranch is the possibility to establish a label of their meat with
superior quality tenderness designation by the USDA.
Bibliography
Bruns K.W., Wulf D.M., Pritchard R.H., 2000. Steps for Warner-Bratzler Shear Force
Assessment of Cooked Beef Longissimus Steaks at South Dakota State University. 72-78.
Darrell J.P., 2007. Tough Criollo a Solution in Dry Times? ABQ Journal Business
Halladay K., 2013. USDA sets beef tenderness standards. Livestock Journal. 15.
Price D.K., Price J.W., 2013. Tenderness: it’s in the genes.
Wheeler T.L., Shackelford S.D., Koohmaraie M., 2005. Shear Force Procedures for Meat
Tenderness Measurement. 1-7