Given recent activities pertaining to meat quality, we would like to provide a short summary of the Brahman Cattle Breeders’ Society’s positioning, and what the goals and targets are with regard to the quality of Brahman meat.
Two sets of data are currently available for the Brahman breed: One from bulls slaughtered during the Beef Genomics Programme (BGP) and tested at the ARC-Animal Production (API), and another from the recent Phase C and D test at Bufland, tested at the University of the Free State (UFS).
The first group constitutes 203 samples and the second 51 samples. Both sets of samples were taken from animals in which no growth stimulants were administered.
Bufland data: The test
Originally 154 bulls representing 18 Brahman members participated in a Phase D2 test at Bufland. At the same time, some of the bulls entered a Phase C test, which yielded an additional residual feed intake (RFI) value.
RFI is currently being analysed for the Brahman to yield a net feed estimated breeding value (EBV), which identifies more economical animals in terms of feed consumption.
The average age of the bulls was 15,7 months, and 49 sires were represented in this group. This is indicative of the group’s wide genetic composition and is particularly good as it allows identification of a wide spectrum of bloodlines, producing more economic animals.
After completion of the test, the bulls were evaluated according to breed standards.
The slaughter group
After a test phase of 112 days (adaptation = 28 days, test = 84 days) and finishing of 27 days, 51 bulls were slaughtered at Vencor in Polokwane. Thirty sires were represented in this group, offering quite a wide genetic range in the tests.
The samples were removed and transported to the UFS in Bloemfontein.
At the UFS meat laboratory
Once at the laboratory, the following procedure was followed:
- A 4cm thick steak was removed and aged for seven days.
- Warner-Bratzler Shear Force was determined on the cooked aged steak.
- The remainder of the loin cut was prepared to determine intramuscular fat content (marbling) by chemical analyses.
- Eye-muscle area was determined by video image analysis (VIA) on the transparency of the muscle that was traced at the abattoir.
The shear force results obtained from the 51 bulls are reflected in Figure 1. Prof Arno Hugo of the Department of Microbial, Biochemical and Food Biotechnology’s Food Science Division conducted the tests.
Some of Prof Hugo’s observations
The average marbling percentage is 0,91, ranging between 0,44 and 2,33%. Although very low, it is to be expected in such young animals. A minimum of at least 4% is required for it to have an effect on meat flavour and juiciness.
The Warner-Bratzler Shear Force (tenderness) of the seven-day aged meat samples were very good. It ranged from 1,45 to 3,94kg with an average shear force value of 2,5kg. For retail purposes a shear force value below 4,6 is considered acceptable. All the samples adhered to this requirement. For food service use, a shear force value below 3,9 is considered acceptable (only one sample had a shear force value above 3,9kg). It is quite impressive that nearly all the seven-day aged meat samples were acceptable for use in the restaurant industry.
A large variation in eye-muscle area was also observed between individual carcasses. Eye-muscle area ranged between 4 306,13 and 8 208,93mm2 with an average of 6 684,46mm2. A larger eye-muscle area was reported to be associated with a higher meat content in the carcass.
The absence of dark cutting meat is a sign of good animal temperament, good transport conditions and proper handling before slaughter. The absence of dark cutters is usually a clear indication that stress was limited during the transport and slaughtering process.
Two important messages
Producers need to take note of the following:
- Variation within the breed does exist, which implies that selection for tenderness can be done.
- According to Prof Hugo, there was no indication of a significant correlation between hump height and tenderness.
Shear force is an indication of meat tenderness and as we know, Zebu-type cattle are the black sheep of tough meat, along with the perception that the higher the hump, the tougher the meat. There is a tendency among various institutions to discriminate against humped cattle. However, both these ideas can be refuted with these tests, and the promise of selection potential is again accentuated.
Brahman Society goals and targets
The Brahman Cattle Breeders’ Society is committed to seeing through the actions initiated by the BGP, namely the creation of a reference population for all the Brahman traits, serving as a starting point to produce genomic estimated breeding values (GEBVs). Meat quality is of such importance that, while it will take longer to accumulate enough samples to initiate the calculation of an EBV, it remains a priority.
What and why of shear force
Warner-Bratzler fixtures measure the force required to cut through a piece of meat. The fixture consists of a steel frame supporting a triangular shear blade. To test a meat sample such as steak, the steak is cooked, cooled and then cut into core samples. The blade then cuts the samples; the force used to cut through a core sample is expressed in kilogram.
This test measures the maximum force (N) as a function of knife movement (mm) and the compression to shear (cut off) a sample of meat (MPa). – Article supplied by the technical team, Brahman Cattle Breeders’ Society of South Africa
For more information, contact the Brahman Cattle Breeders’ Society on 051 446 4619/446 3452 or visit www.brahmanshop.co.za.