EVALUATION, DEVELOPMENT, AND USE OF GENETIC RESOURCES TO IMPROVE LIFE-CYCLE EFFICIENCY OF BEEF CATTLE AND SHEEP
Location: Genetics, Breeding, & Animal Health
Title: Impact of Bos indicus genetics on the global beef industry
Submitted to: The American Brahman Review
Publication Type: Trade Journal
Publication Acceptance Date: July 19, 2012
Publication Date: July 31, 2012
Citation: Cundiff, L.V., Thallman, R.M., Kuehn, L.A. 2012. Impact of Bos indicus genetics on the global beef industry. The American Brahman Review. 3(4):49-52. Available: http://www.brahmanreview.com/view-issues.html.
More than half of the cattle in the world are maintained in tropical environments between the tropics of Cancer and Capricorn. In the U.S., about 40% of the beef cows are located in subtropical environments of the hot and humid Southeast or more arid Southwest. Results of research documenting the importance of using crosses of Bos indicus breeds (e.g., Brahman, Sahiwal, Nellore, Boran) with Bos taurus breeds (e.g., Angus, Red Angus, Hereford, Charolais, Simmental, Gelbvieh, Limousin, etc.) for beef production in these regions to exploit heterosis and match genetic potential of cow herds with the climatic environment is reviewed. In the harshest tropics of the world, cow herds with at least 75% Bos indicus germplasm may be optimal. In hot and humid subtropical regions such as the Gulf coastal U.S., cow herds with 50:50 ratios of Bos indicus to Bos taurus inheritance are more optimal. A little further north in more intermediate subtropical regions of the U.S. (e.g., much of Texas, Southeastern Oklahoma, central Arkansas, Tennessee, and parts of North Carolina), cow herds with 25:75 ratios of Bos indicus to Bos taurus inheritance appear to be more optimal. Bos indicus X Bos taurus crosses excel in cow efficiency, productivity, and longevity, due in great part to extra heterosis in Bos indicus X Bos taurus breed crosses (50%) compared to Bos taurus X Bos taurus breed crosses (25%). However, even in subtropical regions, these advantages are tempered by older age at puberty, and reduced meat tenderness. Systematic crossbreeding programs can be used to manage these trade-offs. To optimize quality grade and yield grade of slaughter progeny, it may be advisable to terminally cross to Bos taurus breeds or to hybrid or composite bulls with 50:50 ratios of Continental European (e.g., Simmental, Charolais, etc.) to British (e.g., Angus, Shorthorn, etc.) breed inheritance. Registrations in breed associations indicate that use of germplasm from Bos indicus breeds peaked at about 17% in the mid-1980’s and has decreased significantly to about 8% in recent years. With 40% of the cows located in subtropical regions of the U.S., to optimize the influence of tropically adapted germplasm in beef production, it is estimated that about 12 to 15% of the seedstock used in commercial production should originate from breeds adapted to tropical or subtropical environments.