By Joe C. Paschal, Professor Emeritus and Livestock Specialist
The USDA Meat Animal Research Center at Clay Center, NE, is the largest federal beef cattle research station in the U.S. It might be the only one, except for those at the landgrant universities, and one of the few with any interest in the Brahman breed and its composites. A number of outstanding scientists have worked at USMARC over the past 60 years. USMARC also maintains a large flock of several breeds of sheep and a large swine herd. The site was a former naval ammunition storage facility that was transferred to USDA in 1966. A project to evaluate the different breeds of cattle in the U.S. was begun shortly after the transfer, using AI from notable sires in several breeds bred to Angus and Hereford. The first calf crops (Cycle I) were sired by Hereford, Angus, Jersey, South Devon, Limousin, Simmental and Charolais. Brahman cattle were included in Cycle III (and others), born in 1975.
It was interesting to note that those calves, when compared to the other breed cross contemporaries, were slightly heavier at weaning and yearling but had similar carcass weights, ribeye area and fat thickness. They were one marbling score lower than the Angus-Hereford crosses, grading High Good (now Select) to their Low Choice. Birth weight was about 10 pounds heavier than Angus- and Hereford-sired calves. The Brahman crossbred heifers were heavier and older (20 days) at puberty, but the calving and weaning rates were similar to the other breeds.
Brahman genetics have been sampled numerous times in USMARC projects, and more than 100 research reports have documented their performance. The breed is well represented in the current (since 2007) Germ Plasm Evaluation (GPE) project that has sampled the 18 most prominent beef breeds in the U.S., including 11 that conduct national cattle evaluations (like ABBA).
The Across Breed EPD Table, published annually (and printed in this month’s The Brahman Journal), is an example of how USMARC makes its results meaningful to breeders and cattle raisers. Many Brahman breeders are interested in using Hereford, Angus or other breeds to create F1s. Knowing how to compare one sire (or dam) breed to another is the function of Table 1. Use the values in the table to accurately adjust for the differences in the breeds’ EPDs. Table 2 lists the breed-of-sire averages for the 18 breeds. You can use this table to predict performance when comparing two different breed bulls to be used with cows of a third breed.
Hybrid vigor is always important to Brahman breeders when discussing crossbreeding. After all, the Brahman is famously known as “Crossbreeding’s Common Denominator.” Recently, Dr. Bailey Engle (with others) published a paper on breed-specific heterosis for growth and carcass traits from the 18-breed project. We all know that heterosis, or hybrid vigor, is population-specific. Hybrid vigor in your herd of Brahman- Hereford F1s will most likely be different than that of someone else’s herd.
Hybrid vigor is not stationary. Since it is caused by genes and their interaction, as some are selected to increase and others removed, their impact on hybrid vigor can change the level of hybrid vigor expressed. As a result, estimates of hybrid vigor of specific crosses and traits should be updated over time. I won’t go over the entire paper. Brahmans were well represented, but as F1s because of the winter weather conditions observed in Nebraska.
The good thing is that they are developing a large herd of Brahman F1s specifically to study their genetics and environmental response. The study evaluated heterosis using 25 “genetic groups.” The 18 breeds constituted part of those, as well as the base cows. These were then assigned an “ancestral breed” group. Breeds assigned to the same ancestral group show little or no hybrid vigor (e.g., Angus and Brangus or ChiAngus).
Brahman has no ancestral breed (at least at USMARC). Finally, the ancestral breeds were assigned a biological group indicating their origin (e.g., Angus, Hereford, etc., were British; Charolais, Simmental, etc., were Continental). Brahman became its own biological group. As expected, biological group heterosis estimates were high for Brahman, at least double (often more) for birth weight, weaning weight, gain, ribeye area, fat and carcass weight. It was large and negative for marbling score, especially in crosses with the British biological group.
If using Brahman on British breeds for carcass merit, emphasize marbling in the British breed. These results indicate that Brahmans continue to cross well with British and Continental breeds across the board. The average breed heterosis estimates for Brahman were in line with expectations. Among the highest for birth weight direct (8.1 lb), but second best for maternal effects on birth weight (-3.7 lb), emphasizing the importance of the crossbred Brahman female. Hybrid vigor for weaning weight was also high at 109.8 lb (second to Beefmaster, which is 50% Brahman), with hybrid vigor for maternal weaning weight at 86.0 lb. Hybrid vigor for marbling score was only slightly negative (-0.1, or about 10% of a marbling score), but hybrid vigor for ribeye area was a whopping 2.6 sq. in. Brahman hybrid vigor added 219.1 lb to carcass weight.
No matter how good these results are, your results may be — and probably will be — different. However, this research indicates the power of the Brahman breed and its genetics to off er the U.S. beef industry the type of cattle needed to rebuild its cowherd in warmer climates without suff ering loss of performance. In closing, I want to quote a couple of comments made in the conclusions by the authors: “The greatest increases in calf performance were estimated for crosses containing Brahman, in particular for growth traits and maternal ability.” And a little later: “Again, the greatest increase in calf performance across a majority of traits was estimated to be a result of crosses with Brahman.” Th e Brahman performance was so outstanding, it was worth repeating. If you would like a copy of the article, drop TBJ or me a note.
