Changes in the U.S. Cowherd and Their Implications on Heifer Development

• Published in: Journal of animal science 2018-03, Vol.96, p.25-26
• Main Authors: Lalman, D L, McGee, A L, Spencer, C M, Wiseman, A R
• Format: Article
• Language: English
• Subjects: Animal reproduction; Artificial insemination; Beef; Beef cattle; Bovidae; Breeding of animals; Cattle; Fertility; Genetics; Longevity; Performance indices; Pregnancy; Progeny; Reproduction (biology); Reproductive technology; Selective breeding; Synchronism; Synchronization; Veterinary surgeons; Weaning
• ISSN: 0021-8812; 1525-3163

Recently, we estimated the total cost of a retained commercial 2-yr-old cow at the time of first calving to be about $1,350 under a typical management scenario in Central Oklahoma. Similarly, spring-calving Show-Me-Select heifers sold for an average of $1,796 during fall 2016. Heifer selection and development from weaning through first calving represents a major long-term investment that must be supported by the rest of the herd for up to 3 years. Moreover, in a program where retained heifers are the sole replacement female source, heifers represent the only avenue to inject new maternal genetics into the cow herd. Consequently, selection and development of heifers to insure an appropriate match to ranch resources, low cost of production, and reproductive longevity should not be overlooked. Industry data as well as breed association genetic trends indicate continued aggressive selection for growth and carcass weight per finished animal. This has led to increased beef production per cow; the industry will produce 14% more beef in 2017 with 1.8 million fewer cows compared to 1992. During this 25-yr period, commercial cow/calf reproductive efficiency has not improved. While effective selection tools for growth have been available for many years, genetic tools to facilitate improvement in fertility are recent in comparison although developing at a rapid pace. Heifer pregnancy and stayability expected progeny differences are the exception with over 20 years of progress in some breeds. In fact, genetic trend for heifer pregnancy in Angus, Red Angus and Gelbvieh breeds indicate gradual improvement over time. Similarly, genetic trend data indicate slow although consistent improvements have been made in stayability for Red Angus, Simmental and Gelbvieh cattle since implementation around 1995. In the future availability of genetic tools, including genomic enhancements, will allow increased selection intensity for cow herd fertility and longevity traits. Subsequently, increased adoption of synchronization and artificial insemination protocols will enable broader use of sires with daughters proven to excel in sustained fertility. Finally, comprehensive selection indexes to include fertility traits will lead to concomitant improvements in reproductive efficiency, finishing-phase performance and carcass value. By combining these genetic and reproductive technologies, beef cattle producers, extension educators and veterinarians will have the opportunity to facilitate sub