Our Research
Feedlot Trials and Meat Studies Using ½ Mashona Steers
In the fall of 2000, Weaver Ranch sold 71 half Mashona steers to New Mexico State University's feedlot research station at Clayton, New Mexico. NMSU bought the steers to put into a feeding trial utilizing different protein levels. The steers were all sired by Mashona bulls, out of mostly Angus and Brangus dams. Weaver Ranch sorted their steers prior to the sale, selling only the average steers to NMSU.
The steers were on feed for 210 days, then were sold on the grid. The steers’ performance was outstanding, with more than 90% grading Prime or Choice, and a yield grade of 2.87. At 641 pounds, the carcasses were lighter than average, but still "fit the box" of the slaughter industry. A staff member at Clayton told Weaver Ranch that he had calculated the equivalent price on-the-hoof based on the grid price received in the meat; these steers had beat the live price for that day by more than $10 per hundredweight (more than $100 per animal).
Fall 2001 Feedlot Trials
Encouraged by the results from Clayton, Weaver Ranch placed three additional groups of half Mashona steers on feed in the fall of 2001: 30 head placed at Bar G Feedyard, Summerfield, Texas, in September; 5 head with the Texas Ranch to Rail North program at Swisher County Feedyard, Tulia, Texas, in October; and 46 head with the New Mexico Ranch to Rail program in November, also at Swisher County Feedyard. Once again Weaver Ranch sent average steers to the feedlot, holding back the best and biggest and a handful of smaller or younger animals.
Bar G Feed Yard Results
The 30 head at Bar G were on feed for 189 days, then were sold on the grid to an Excel packing plant. Staff from the Meat Sciences Laboratory at Texas Tech University, Lubbock, Texas, followed the animals through the plant, recording quality and yield data, and collecting samples for further testing at the Meat Lab.
The Bar G steers also performed exceptionally. Two animals graded Prime and 24 head graded Choice (86.7% Prime and Choice). Four of those animals additionally qualified for the "Angus Pride" price bonus. All but one of the animals returned a yield grade of 2 or 3, for a final average of 2.6. Carcass weight of this group averaged 795, with a dressing percentage of just under 65%, and a ribeye area of just over 13 square inches.
Staff at the Texas Tech Meat Sciences Laboratory performed the Warner-Bratzler shear test for tenderness on six samples from each carcass. A result of three kilograms or less in this tenderness test has been found to be 100% acceptable to the consumer. The results on the Weaver steers ranged from a low of 1.61 kg. to a high of 3.03 kg. (the only carcass to exceed 3.0). The average of all shear results was 2.21 kg., with almost 26% scoring below 2.0.
Tech Meat Lab staff also cooked six samples from each carcass and presented these samples in a blind taste test to members of a Sensory Panel. Members of the Panel then judged each sample on Initial Juiciness, Sustained Juiciness, Initial Tenderness, Sustained Tenderness, Flavor Intensity, Beef Flavor, Overall Mouthfeel, and Off Flavor. All of the categories were scored on a scale of 1 to 8. In the first seven categories 8 is the best score and in Off Flavor 1 is the best score.
SENSORY PANEL RESULTS
|
CATEGORY |
HIGH |
LOW |
AVERAGE |
|
Initial Juiciness |
7.3 |
5.3 |
6.31 |
|
Sustained Juiciness |
6.8 |
5.3 |
6.03 |
|
Initial Tenderness |
7.5 |
5.7 |
6.53 |
|
Sustained Tenderness |
7.2 |
5.2 |
6.31 |
|
Flavor Intensity |
7.0 |
5.7 |
6.27 |
|
Beef Flavor |
7.0 |
5.5 |
6.41 |
|
Overall Mouthfeel |
7.0 |
5.8 |
6.37 |
|
Off Flavor |
1.2 |
1.0 |
1.01 |
Weaver Ranch was assured by the Meat Lab staff that these Sensory Panel results are very good.
Texas Ranch to Rail Results
The group of five steers placed in the October Texas Ranch to Rail program, conducted by Texas A&M University, was unquestionably a statistically small sample size, and this was emphasized when one steer died of respiratory sickness at the feedlot. This unfortunate death is made slightly more palatable by being the only death among the 152 head Weaver Ranch has placed on feed during the last two years, a death loss of just over 0.6%. Only two of the last 50 steers have been doctored.
The four half Mashona steers each graded Choice. Average ribeye area was 14.4 square inches, dressing percentage was 65.5%, and average Yield Grade came in at 2.75.
The four Weaver half Mashona steers produced an average profit of $36.83 each, while the average for the entire Texas Ranch to Rail program was a loss of $10.95 per head.
New Mexico Ranch to Rail Results
The 46 half Mashona steers placed at Swisher County Feedyard for New Mexico State University’s New Mexico Ranch to Rail program out-performed the other 144 cattle in the program.
The half Mashona steers produced 778 pound carcasses with ribeye area of 14 square inches and a dressing percentage of more than 65%. Nearly 85% of the carcasses were Yield Grade 1 or 2, with an average of 1.95. Our half Mashona steers received a Quality Grade of Choice more than three times as often as the other cattle in the program.
The 46 Weaver half Mashona steers made an average profit of $40.89 each. The other 144 head of non-Mashona cattle in the test averaged a loss of $67.81 each. They out-performed the non-Mashona cattle by more than $100 per head.
Grass-fed Beef Research Summary
Our Grass-fed Test Subjects
On October 8th and 10th, 2002, seven half-Mashona steers from Weaver Ranch near Causey, New Mexico were harvested at Texas Tech University’s Meat Sciences Laboratory at Lubbock, Texas. Prior to being hauled to Lubbock, the steers had been on predominantly native grass pasture with no supplemental feed.
Five of the steers were about 30 months old, and the other two were about 24 months old. The older steers averaged 1191 lb. live weight, and 685 lb. hot carcass weight, for a dressing percentage of 57.5%, with a ribeye area of 11.7 in2 and a final Yield Grade of 2.16. The two younger steers were somewhat smaller at 948 lb. live weight and 549 lb. hot carcass weight, for a dressing percentage of 57.9 %. The younger steers averaged 9.25 in2 ribeye area and brought in a final Yield Grade of 2.12. Four of the steers were Quality Graded as Standard Plus, two as Select Plus and one was graded Choice.
The sides of beef were aged for 21 days at the Meat Lab before being processed into the various cuts. The carcasses were cut up so as to maximize the “value added cuts”, allowing more tender and valuable cutlets to be separated from ordinarily “tough” cuts such as chuck or round.
The five older steers averaged almost 306 lbs. of boneless steaks and roasts, with another 168 lbs. of lean trim and 38 lbs. of trimmed fat. The younger steers averaged 245 lbs. of boneless cuts, 128 lbs. of lean trim and 24 lbs. of fat. Part of the lean trim was packaged as fajita or stew meat, and the remainder was mixed with a portion of the fat for ground beef. The meat was USDA inspected and the cuts individually vacuum-packed and frozen.
Sensory Panel and Shear Tests at Texas Tech
Tech Meat Lab staff kept a ribeye steak from each animal for analysis. A trained Sensory Panel was assembled and given samples of each steak in a blind taste test. Panel members rated each sample on the basis of: Initial Juiciness, Sustained Juiciness, Initial Tenderness, Sustained Tenderness, Flavor Intensity, Beef Flavor, Overall Mouthfeel and Off Flavor. All categories are rated from 1 to 8. Eight is the best in all categories, except Off Flavor in which 1 is the best rating.
The sensory panel results (see figure 1) were a little lower than we had gotten from a test of feedlot grain-fed half-Mashona steers in Spring 2002, except in the categories of Flavor Intensity and Beef Flavor, where the grass-fed steers scored .2 to .3 points higher than their grain-fed brothers. (A summary of the research on the excellent feedlot performance of our half-Mashona steers may be found at www.AmericanMashona.com, or contact us and we will send you a copy.)
Sensory Panel Results for Weaver Grass-fed half-Mashona Steers
|
Category |
High |
Low |
Average |
|
Initial Juiciness |
6.38 |
5.17 |
5.81 |
|
Sustained Juiciness |
6.75 |
5.0 |
5.93 |
|
Initial Tenderness |
6.63 |
4.83 |
5.65 |
|
Sustained Tenderness |
6.88 |
5.17 |
6.11 |
|
Flavor Intensity |
7.0 |
6.0 |
6.48 |
|
Beef Flavor |
7.13 |
6.0 |
6.70 |
|
Overall Mouthfeel |
6.38 |
5.17 |
6.02 |
|
Off Flavor |
1.0 |
1.0 |
1.00 |
Figure 1
The Texas Tech Meat Lab staff also performed the Warner/Bratzler Shear Test (WBS) for tenderness. In this test, uniform cores of cooked meat are removed from each steak, and subjected to a measured shear force. The kilograms of force required to shear the sample are recorded. Six lean meat cores from each steak are sheared, and those results are averaged to make the WBS score for each animal. A WBS score of 3.0 kg or lower has been found to be 100% acceptable to the consumer on the basis of tenderness.
We believe our results on the grass-fed beef to be very good. The seven steaks averaged 2.81 kg. Five steaks scored below 3.0 kg. Our highest (toughest) steak had a WBS score of 3.3 kg, while our best steak had a WBS score of 2.2 kg. The highest reading from any of the six individual shear tests on any steak was 4.4 kg, and our lowest individual reading was only 1.3 kg.
Comparison of Our Grass-fed Results to Published Grain-fed Results
Following these pleasing findings, we began to search the Internet for comparable beef studies. At http://ansci.colostate.edu/ran/beef/2002/pdf/mrg02.pdf, we found “Comparison of the Palatability of Five Different Beef Product Lines” by M.R. Genho, K.E. Belk, J.A. Scanga and G.C. Smith.
In this study, the authors compared USDA commodity Choice and Select loin steaks to: Brand A – an upper 2/3 Choice branded beef line; Brand B – a lean branded beef line; and Brand C — a guaranteed tender branded beef line. Comparisons were made on the basis of Warner/Bratzler Shear tests and taste tests by a trained Sensory Panel. For the purposes of this report, we have converted their WBS scores from pounds into kilograms.
The Sensory Panel used in the study rated the following categories on the basis of 1 to 8 (8 is the best reading): Juiciness, Fiber Tenderness, amount of Connective Tissue, Overall Tenderness and Flavor Intensity.
In Juiciness, the panel rated the samples from 5.6 to 6.1. The average for our grass-fed steaks’ readings for Initial Juiciness and Sustained Juiciness was almost 5.9.
In Overall Tenderness, the panel from this study rated their samples from 5.8 to 6.5. The average from our grass-fed steaks’ readings for Initial Tenderness and Sustained Tenderness was just over 5.8.
In Flavor Intensity, this panel rated their samples from 5.4 to 5.8. Our Sensory Panel result for Flavor Intensity on our grass-fed steaks was substantially higher at 6.48.
In the Warner/Bratzler Shear tests, the study reported Mean WBS scores ranging from 2.7 kg for Brand A to 3.4 kg for Brand B. We feel that our average WBS score of 2.81 kg from cattle grown and fattened on grass is very good.
The minimum WBS scores from the study ranged from 1.9 kg to 2.2 kg, with our lowest grass-fed result being the steak with a WBS score of 2.2 kg. On the tougher end, our results were especially outstanding. The highest WBS scores from the study ranged from 4.3 kg all the way up to 5.1 kg. The highest WBS score on any of our grass-fed steaks was only 3.3 kg.
All five product lines evaluated in the study were from grain-fed beef. Grass-fed beef is often assumed to be tough, dry and too “gamey” tasting. These results show that our grass-fed beef can hold its own in a head-to-head comparison with grain-fed beef.
Fatty Acid Profile and Analysis at University of Wyoming
As part of our on-going research into grass feeding, in March 2003 we had a Fatty Acid Profile run on each of the seven grass-fed animals at the University of Wyoming’s Department of Animal Sciences. Staff there prepared a lean meat core sample out of ribeye steaks we sent to them. Each sample was analyzed to determine which fatty acids were present, and in what amount.
When we scheduled these tests, we were most interested in the levels of Conjugated Linoleic Acid (CLA) and fatty acids Omega-6 (18:2) and Omega-3 (18:3). Current research is confirming the health benefits of CLA in the diet and the beneficial effects of eating a diet with the proper balance of Omega-6 to Omega-3, i.e. a ratio ranging from 4:1 to 1:1, rather than the imbalance provided by grain-fed beef, in which the ratio can be 20:1.
We were encouraged by finding our ratios of Omega-6:Omega-3 in the 3:1 to 4:1 range, but also a little surprised by another of the findings of the fatty acid profile. The staff reported having seen substantial marbling in the steaks during sample preparation, which was confirmed when the analysis returned unusually high readings for the fatty acids created by the animal as marbling (16:0, 18:0, and 18:1). The analysis showed a lean muscle total fat content of 2.1% in the two younger steers and more than 6.8% in the five older steers. The staff had not expected this amount of marbling from grass-fed cattle with no supplemental feed.
In Summary
Mashona bulls from Weaver Ranch sired each of the seven steers. The dams were mostly Angus or Brangus commercial cows. The Mashona is a sanga type of Bos indicus from southern Africa. Our seed stock was imported as embryos from a carefully selected group of donors in Zimbabwe beginning in 1995. The Mashona were reported in Zimbabwe to be known to put on marbling before back fat. This would help to explain our outstanding results, first in grain-fed half-Mashona feedlot steers, and now in grass-fed half-Mashona steers.