by: Steven B. Blezinger
The last few years have provided some exiting developments in the area of biotechnology in the beef industry. Tools such as DNA markers for economically important traits, sexing of semen and embryos, in vitro production of embryos, cloning and other breakthroughs brought about for the most part by work in the field of molecular biology are some specific examples. Interestingly though, one of the most significant of these, a tool that has been around the longest and one of the most effective genetic improvement tools available today is largely underutilized by the beef industry - artificial insemination (AI). This article will review what AI has to offer to the beef cattle producer and attempt to illustrate some of the production and economic benefits of this powerful resource. A large portion of this text is taken from a discussion by Dr. Harlan Ritchie at Michigan State in Feedstuffs (Oct 05).
Artificial Insemination has been around since 1939, for over 65 years. However, less than five percent of the nation's beef cows are bred AI, with the majority of these breedings taking place in the seedstock and the club (show) calf sectors. As a point of comparison, about 66 percent of the nation's dairy cows are bred AI, and the use of AI by commercial swine producers is currently 70-75 percent. At one time, AI was considerably more expensive than natural service. This is no longer the case in today's beef industry and market. Also, at one time, the bulls that were available as AI sires were not that much better genetically than those in countless pastures in the United States. Today, however, semen is available from AI sires significantly better than most breed averages in most traits are available at a nominal price. Finally, developments in estrus synchronization (ES) systems make the use of AI much more feasible.
In our current cattle markets, AI is not just for purebred breeders but has applications at the commercial level as well. Use of many highly proven AI sires in an assortment of breeds or even crosses can:
1) Significantly increase weaning weights.
2) Improve post-weaning performance.
3) Enhance carcass value.
4) Perhaps most importantly, result in more productive and valuable replacement heifers.
The big question, remains though; "Can these benefits justify the costs of AI?" Recent studies conducted by a number of university and industry researchers suggest that they can, depending on the individual producer's situation. It is also noteworthy that as the beef industry becomes increasingly product and consumer oriented and the national animal identification system is implemented, genetic background will take on greater importance. This may be one of the greatest driving forces for increased use of AI. Also, customers “downstream” from the cow-calf sector (feedyards, packers, etc.) may become familiar with the top AI sires and place added value on their calves.
Some Facts and Figures
In a study by Johnson and Jones (2004), based on an extensive survey of beef producers, they used the following costs for their economic projections: natural service bulls, $2,300; semen, $14 per straw of semen; prostaglandin (PG), $2.54 per dose; gonadotropin releasing hormone (GnRH), $3.21 per dose; melengesterol acetate (MGA), two cents per head per day; CIDR, $9 per insert; total fixed costs of AI (semen tank, etc.), $175.00; labor, $10.77 per hour and the interest rate for cash costs, seven percent.
Since AI pregnancy rates generally range from 40 to 60 percent; for this example, 50 percent was used. The number of bulls required for cleanup was based on the assumption that one bull was needed per 30 non-pregnant females. Pregnancy rate for the total breeding season was 94 percent (higher than the US natural service average). The AI-sired calves were assumed to be an average of 10 days older and 20 lb. heavier at weaning, thereby returning an additional $25 if the additional weight was worth $1.25/lb. For this study, natural service-sired calves were valued at $500 and AI-sired calves at $525 per head. Breeding system costs per exposed female were reduced by any increased revenue from AI-sired calves and expressed as a 500 lb. equivalent weaned-calf breeding cost per hundredweight. A weaned calf crop percentage of 82 percent was used. Table 1 compares the cost of natural service with that of AI using 11 different ES protocols that are currently available. As shown in Table 1, on the basis of a 500 lb. equivalent weaned calf breeding cost, several systems have costs lower than natural service. Several others are only marginally higher than natural service. Systems involving CIDRs tend to have the highest standardized cost per hundredweight.
As noted before, natural service bulls were priced at $2,300. This was based on the reported average price of bulls sold from 2000 to 2003. Since then, bull prices have increased significantly, making AI appear more economically feasible than ever. Furthermore, this model did not account for the potential added value of Al-sired replacement heifers, which would markedly enhance the productivity of the cow herd over time.
Today, the technology exists to successfully inseminate cows at predetermined, fixed times with resulting pregnancy rates that are equivalent to those achieved with heat detection. This is illustrated in Table 2, which is a summary of results from University of Missouri published work, in addition to unpublished data from DeJamette and Wallace of Select Sires Inc.
University of Kentucky researchers Les Anderson and Paul Deaton (2003) conducted a study comparing ES and AI with natural service using 351 commercial crossbred cows (Anderson and Deaton, 2003). The ES/AI treatment consisted of a 10-day CO-Synch protocol with fixed-time AI at 48 hours after a second injection of GnRH. Cost of ES/AI, including labor, was $29.88 per cow. Following AI, cleanup bulls were turned out for 50 days at a cow:bull ratio of 50:1. The natural service cows were exposed to bulls for 60 days at a cow:bull ratio of 25:1. Calves in both treatments were given a value of $80/cwt., which was the going market value for weaned calves at the time. As shown in Table 3, cows in the ES/AI treatment weaned 109 lb. more calf per cow exposed than those bred by natural service. The extra revenue generated in the ES/AI treatment would be 109 lb. x 80 cents = $87.20 per cow. Therefore, net return on the investment in ES/AI would be $87.20 - $29.88 = $57.32 per cow. This does not include the important long-term economic benefits of increased maternal productivity that could accrue from retaining heifers sired by highly proven AI sires.
To sum it all up, recent research in reproductive physiology has improved and refined AI and ES systems, making them more feasible than ever before for the beef industry. Additionally, the research has shown that adopting AI and ES lends itself to increased profitability and a dramatic increase in the overall quality of the producer's herd.
Dr. Steve Blezinger is and nutritional and management consultant with an office in Sulphur Springs Texas. He can be reached at 667 CR 4711 Sulphur Springs, TX 75482, by phone at (903) 885-7992 by e-mail at [email protected] You can also check out BLN Consulting at www.blnconsult.com.