Nutrient Density of Beef From Longhorn Cattle
Preliminary Research Report #1
Here are the results of the Nutrient Density of Beef From Longhorn Cattle project:
During 1984 and again in 1985 and ‘86, the TLBAA set as its highest priorities; 1) research on Texas Longhorn cattle, and 2) promotion of them. These priorities made a lot of sense because in time, we could expect to use research results in our promotional campaign. However, there emerged a “hitch” in these “best laid plans.” The Association’s budget fell short, and there was not sufficient money for research ($20,000/year) as planned.
During 1986, thanks to loans from two breeders, donations from approximately 30 others and contributions from some affiliate associations, we were able to sponsor a project at Texas A&M University entitled: “Nutrient Density of Beef from Longhorn Cattle” (1986 Texas A&M Study). This research project was timely because of the clear preference for lean, wholesome beef by the American consumer. We need solid evidence of the merits of Texas Longhorn beef in today’s market; the A&M Study is designed to search for the evidence.
The purpose of this study was to compare the nutrient composition of red meat (fat, fatty acids, cholesterol and other nutrients) from three groups of cattle - straight Texas Longhorns, Longhorn x Hereford crosses and straight Herefords, all of the same age and following the same feeding regime. Each of the three groups of cattle were further divided so that some were fed to reach a live-grade of “good” and the others were fed an additional period of time to reach a “choice grade.” Table 1 shows the division of the groups of cattle for the feeding trials.
Table 1. Feeding groups of Texas Longhorns, Texas Longhorn x
Hereford Cross and Herefords.
Breeding Total Good Choice
Grade Grade
Texas
Longhorns 25 Group 1 (13) Group 2 (12)
Longhorn
Crosses 24 Group 3 (12) Group 4 (12)
Herefords 12 Group 5 (6) Group 6 (6)
It is probably important to note that the Texas Longhorn x Hereford crosses and the Hereford steers all came from the same ranch, and were very good cattle. The crosses (average wt. 615 lbs) were all weaned from first-calf heifers, and were somewhat lighter than the Herefords (average wt. 718 lbs) at the start of the study. The Texas Longhorn steers were good steers, but had to be assembled from different ranches. They were donated or sold to the project by breeders, and they were substantially lighter weight (average wt. 466 lbs) than the other steers at the start of the study.
To date, the 1986 Texas A&M study has been on schedule. The results of this study will be reported to the Association in three steps as the data becomes available. The first set of preliminary data on carcass fat and quality will be reported here. Please note the word “preliminary.” We are asking for the data as soon as available from Texas A&M. This means that we are receiving and releasing some of the data before there has been time for it to be completely evaluated by the scientific staff at Texas A&M. Data to follow in the next 60 to 90 days will be the “meat composition” data, and finally, the full report on all aspects of the study.
Table 2 shows the number of days fed and the carcass weight of each group, and Table 3 shows the backfat thickness, rib-eye area, and percent internal fat around the kidney, pelvis and heart. Table 4 shows the yield grade, marbling score and quality grade of each group.
Table 2. Days Fed and Average Individual Carcass Weight (pounds)
of Each Group.
Breeding and Group Days Fed Carcass Weight
Texas Longhorns
Group 1 179 470
Group 2 210 525
Longhorn Crosses
Group 3 116 565
Group 4 176 630
Herefords
Group 5 93 594
Group 6 148 680
Before discussing this data, a reminder of the meaning of “yield grade,” “marbling score” and “quality grade.” The USDA has established grades to represent the differences in both the quality and quantity of edible meat in a beef carcass. The differences in quality of the meat are represented by the USDA quality grades and differences in quantity of amount of salable lean are represented by the USDA yield grades.
Table 3. The Backfat Thickness (BFT), Ribeye Area (REA), Percent
Internal Fat (PIF) of Each Group.
Breeding and Group BFT REA PIF
(in.) (sq. in.) (%)
Texas Longhorns
Group 1 0.23 8.7 3.3
Group 2 0.27 9.7 2.9
Longhorn Crosses
Group 3 0.33 10.6 2.8
Group 4 0.47 10.4 2.3
Herefords
Group 5 0.43 10.5 1.8
Group 6 0.73 10.2 1.8
Table 4. The Yield Grade, Marbling Score and Quality Grade
of Each Group.
Breeding and Group Yield Marbling Quality
Grade Score Grade
Texas Longhorns
Group 1 3.0 355 5.2
Group 2 3.0 359 5.3
Longhorn Crosses
Group 3 3.1 294 3.8
Group 4 3.6 425 6.5
Herefords
Group 5 3.0 338 5.0
Group 6 4.5 357 5.8
USDA Beef quality grades are meant to be indices in determining carcass value because they serve as guides to the eating characteristics of the final product. The eating characteristics of beef are measured by the palatability of the cooked product--its tenderness, juiciness, and flavor. The following grade terminology is used: Prime, Choice, Good, Standard, Commercial, Utility, Cutter and Canner. Because the “good grade” is often highly desirable lean beef, but is perceived by the consumer as not being “really good,” there is some chance, in the very near future, that the USDA will change the terminology “good grade” to “select grade.”
The major factors used to determine quality grades are maturity and marbling (extent of lines of fat deposited within the red meat tissue). In general, the older the animal the greater the amount of marbling required to reach a high quality grade. The Texas A&M data is reported with a numerical grading in which the following USDA terms and numbers are equivalent:
USDA TERM NUMERICAL SCORE
CHOICE 7 T0 9
GOOD 4 T0 6
In the Texas A&M data the marbling is graded numerically:
DEGREE NUMERICAL USDA
OF MARBLING SCORE GRADE
FOR STEERS*
Traces 200 Low Good (4)
Slight 300 Medium Good (5)
Small 400 Low Choice (7)
Modest 500 Medium Choice (8)
Moderate 600 High Choice (9)
Abundant 700 Prime (10+)
*This is for steers in the age range of those in the Texas A&M study.
Remember, USDA Quality Grade is dependent upon marbling and age.
Since 1965, USDA Yield Grades (also referred to as cutability grades) have provided an additional marketing tool for use by all who buy or sell cattle and beef carcasses. Yield grades are a means of identifying the most important value-determining characteristics, the amount of trimmed retail cuts that can be obtained from a beef carcass. Specifically, yield grades are based on the percentage of closely trimmed boneless retail cuts from the round, loin, rib and chuck. These four wholesale cuts account for more than 80% of the carcass value. There are five USDA yield grades numbered 1 through 5. Carcasses with yield grade 1 have the highest yield of retail cuts while carcasses with a yield grade of 5 have the lowest yield of retail cuts. Yield grades for beef carcasses are applied without regard to sex or quality grade. Table 5 shows the percent of boneless, closely trimmed retail cuts that can be cut from the round, loin, rib and chuck for each of the five yield grades.
Table 5. Percent of Boneless Retail Cuts from
Round, Loin, Rib and Chuck.
YIELD GRADES PERCENT AGE
1 52.6 - 54.6
2 50.3 - 52.3
3 48.0 - 50.0
4 45.7 - 47.7
5 43.3 - 45.4
Yield grades are determined by using the following four factors; 1) fat thickness, inches; 2) rib-eye area, sq.in.; 3) percent kidney, heart and pelvic fat and 4) hot carcass weight, lbs. The amount of fat over the outside of a carcass is the most important factor in determininng yield grade because it is a good indication of the amount of fat that is trimmed in making retail cuts. I emphasize this point because this is a very strong point in favor of the Texas Longhorn and Longhorn Cross steers in this and other research studies. Table 6 shows the relationship between “thickness of fat over rib-eye” and “preliminary yield grade.”
Table 6. Relationship Between Thickness of Fat over Rib-eye and
Preliminary Yield Grade.
Thickness of fat over Preliminary Yield Grade
Ribeye (in.)
0.2 2.5
0.4 3.0
0.6 3.5
0.8 4.0
1.0 4.5
The rib-eye is the large muscle that lies on each side of the backbone running the full length of the back. When the carcass is separated into a fore- and hindquarter between the 12th and 13th ribs, a cross-section of the rib-eye is exposed. The rib-eye area (REA) is an indicator of the total amount of muscle in a carcass and as REA increases, retail cut yield increases.
The amount of fat in the kidney, heart and pelvic areas also affects carcass yields. As the amount of this fat increases, the percent of retail cuts decreases. The average amount of kidney, heart and pelvic fat is 3.5% of the carcass weight. The actual determination of the yield grade using backfat, REA and internal fat percentage is somewhat complex, and I will not go into it here. Table 7 shows the expected pounds of fat trim, bone and yield grades. The values indicate that as pounds of fat increase from yield grades 1 to 5, the pounds of trimmed retail cuts decrease. There is substantial price differential between grades reflecting the differences in yield of edible lean that the retailer will have available for sale.
Table 7. Pounds of Fat Trim, Bone and Trimmed Retail Cuts
per 100 pounds for each of the 5 Yield Grades.
YIELD GRADES
1 2 3 4 5
Fat Trim 7.6 12.7 17.8 22.9 28.0
Bone & Shrink 10.4 9.9 9.4 8.9 8.4
Trimmed 82.0 77.4 72.8 68.2 63.6
Retail Cuts
Yield grades provide an indirect means for reflecting consumer preferences for beef with a high ration of lean to fat. Thus, they can be effective in bringing about changes which will eliminate much of the waste now present in the production and marketing of beef. When used in conjunction with quality grades, yield grades will provide a means of identifying breeds and/or strains of cattle and production methods which will produce high quality beef with a minimum of waste fat, which should lead to better values for consumers and greater returns for producers. One of the points of this study is to document the carcass value of Texas Longhorns and/or Longhorn crosses.
DISCUSSION OF RESULTS
Keeping in mind that the Longhorn crosses were offspring from first-calf heifers and that they started at a lighter weight than the Herefords, they produced a carcass with essentially the same weight and in nearly the same time as the Herefords (Table 2). The Texas Longhorn steers started lighter and gained less rapidly compared to the other sets of steers. This trend in lower rate of gain for Texas Longhorn steers has been seen in other trials on Texas Longhorns, Longhorn Crosses and other beef breeds.
Note that all of the steers in this study had smaller percentages of internal (kidney, pelvis and heart) fat (PIF) than the average (3.5%) of all slaughter steers (see Table 3). There was not much difference PIE in the three groups of cattle in this study, although the Herefords had the least. It is worth noting that the Texas Longhorns and Crosses that had been on feed longer had lower PIF, suggesting that if they had grown out more, their PIF would have been less. Other studies have suggested that Longhorns and their crosses have somewhat larger PIF. Keep in mind, that although internal fat is considered “wastage,” it is not as undesirable as thick backfat on a finished carcass. In my view, the PIF seen in these steers is not a serious fault.
Of more significance than PIF is backfat thickness (BFT) and rib-eye area (REA) (see Table 3). Both the Texas Longhorn and the Longhorn cross steers had much less BFT than the Herefords. Remember that BFT is the most important factor in determining Yield Grade. This makes lots of sense because internal fat is easily removed with the viscera during processing; whereas, fat cover is expensive to remove. Nowadays, it must be removed by the packer or more often by the retailer.
As indicated above, REA is an index of the total amount of red meat in the carcass. As shown in Table 3 there was no significant difference between REA in the six groups of cattle. It is revealing to look at the REA relative to carcass size (weight) by dividing the REA by Carcass Weight. The results are shown below:
Breeding REA/Carcass Weight (x1O)
Longhorns Group 1 0.19
Group 2 0.18
Longhorn Crosses Group 3 0.19
Group 4 0.17
Herefords Group 5 0.18
Group 6 0.15
This data suggests that the Texas Longhorns and Longhorn crosses have proportionally more red meat (larger ratio of REA: Carcass Weight) in smaller carcasses than did the Hereford which had larger carcasses and no bigger REA.
It is noteworthy that both groups of Texas Longhorn steers achieved a comparatively high Quality Grade with much higher carcasses and with much less BFT (see Table 4). Keep in mind the two major determinants of Quality Grade are marbling and age. It is less clear why the lighter weight group (group 3) of crossbreed steers had a lower Quality Grade while the heavier group (group 4) had the highest Quality Grade. Comparing the heavier (carcass weights) Longhorn crosses (group 4) with the heavier Herefords (group 6), the crosses had a slightly higher Quality Grade and 36% less thickness of backfat. Certainly the very desirable quality of low BFT comes from the Texas Longhorn genetic influence.
It is important to appreciate that better yield grade carcasses may demand $5 to $15 more per hundred than the lower grades. To the extent Texas Longhorn steers are less efficient in feedlot gain than other English breeds, they make up for it in a better quality and yield grade carcass.
The Longhorn crosses gain nearly as well as other breeds and still have better yield and quality grades. This finding is similar to that shown in several earlier studies.
The Texas Longhorn and Longhorn cross steers in this study had the highest “preliminary yield grade,” approximately 2.5 and 3.0 respectively, and the Herefords the lowest, approximately 4.0. The Texas Longhorns lost ground because of their slightly smaller REA and larger PIE. In my view, this is, to a great measure, because the Texas Longhorn steers were slaughtered before they reached a larger carcass size at which time they would likely have had a larger ribeye and a smaller PIE. This has been shown to be the case in earlier studies.
With fat on beef becoming “uglier” to the consumer (and the processor/retailer) it is likely that the price differential will be even greater for carcasses with desirable yield grades and high quality scores compared to those with poorer yield and quality grades. As in earlier studies the Longhorn crosses in this study out-performed a conventional beef breed, and did so in all the “right places” for today’s beef industry.
Some final comments that fall squarely in the category of “my opinion”:
1. As beef producers and processors look for the “right” genetic makeup for their “perfect beef animal”, they need to be looking at the proven “genetic-package” in the Texas Longhorns. While purebred breeders (the source of beef-cattle genetics), commercial producers and processors should focus on those traits that result in a highly desirable product for the retailers and consumers. They cannot lose sight of the traits of cattle that are important to reproductive capacity, mothering and range utilization that raise that calf to weaning age. There may be another breed that may approach the Texas Longhorn in producing a high yield, high quality carcass, but will that breed have the reproductive success, reproductive life-span, mothering ability, and disease resistance of the Texas Longhorn cow?
The point is that all of the traits desirable for the processor and retailer may not be desirable back on the ranch. A case in point is the amount of internal fat. While it may be desirable to have very little internal fat in the fat-steer’s carcass, internal fat is very likely what allows that Texas Longhorn mother to stay beside her newborn calf during the blizzard and not eat or drink for up to 48 hours.
On the other hand, we as Texas Longhorn breeders should select the best of our breed for our breeding programs being aware of the need to contribute to the production of high-quality, high-yielding carcasses. As we do that, we must be always mindful that we don’t lose those highly valued reproductive traits of our breed.
2. It’s my view that Texas Longhorn steers would gain more efficiently in the feedlot under the following conditions: a) they probably would gain better if older than 24 months, b) precondition to feedhunks, and c) slaughter earlier i.e., do not try to make Longhorn steers “look” like other beef breeds.
3. Finally, as Texas Longhorn breeders, we should sell “genetic traits” of our cattle to be used to upgrade other breeds, enabling them to benefit from the accompanying hybrid vigor. I recently saw data from one of the largest ranches in Kansas in which Texas Longhorn-cross cows produced smaller calves at birth than Simmental cows, but at weaning time, the Longhorn bred calves weighed an average of 50 lbs more than the Simmental offspring.
We don’t know how the Texas Longhorn and Longhorn crosses steers’ carcasses fared in the “tasting tests” and meat composition (fat and cholesterol) parts of this investigation, but already the Texas Longhorn genetics have demonstrated (again) their value. Much of what has thus far been shown in this study agrees with data reported in earlier research projects. For some reason or other, the “good news” about Texas Longhorns value in the beef industry has not been spread to the livestock industry. Let’s not keep it a secret any longer. We owe it to the consumer, retailer, processor, feeder and cow/calf operator to let them in on the “good news” about Texas Longhorns.
Here are the results of the Nutrient Density of Beef From Longhorn Cattle project:
"Texas Longhorn Breeders Association of America"
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