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ABS Global, Inc., DeForest, WI 53532
E-mail: dfunk{at}absglobal.com
| ABSTRACT |
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Key Words: progeny test genetic marker Interbull inbreeding
| INTRODUCTION |
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The importation of elite North American genetics into developed dairy countries, especially Western Europe, led to increased international competition among the AI companies in the 1990s. In many cases, elite bulls being progeny tested in the United States had full brothers being progeny tested in Europe. The heavy use of a few key sire lines internationally also led to a global Holstein population that is now quite closely related.
As the AI industry in the United States evolved from regional to national to international businesses, the industry simultaneously went through various consolidations, acquisitions, and mergers. A noticeable change from 1981 is the reduction in the number of major AI companies in the United States. In 1981, 11 AI companies produced 90% of the semen processed in the United States, as reported to NAAB. Today, that same 90% of the semen produced and reported to NAAB is from only 5 AI companies. These 5 companies include 3 large cooperatives (Select Sires, Genex Cooperative, and Accelerated Genetics), 1 privately held company (Alta Genetics, with ownership in the Netherlands), and 1 publicly traded company (ABS Global, traded on the London Stock Exchange as Genus plc).
The ownership of Alta Genetics and ABS Global highlights one of the other major changes in the AI industryglobalization. The AI companies today have either business affiliates in, or marketing alliances with, most key cattle-breeding countries around the world.
What factors contributed to this rapid growth and subsequent consolidation and globalization of the AI industry? Although the dynamics are complex, the broad answer to this question is relatively simple: lots of semen available from bulls that are difficult to differentiate by genetics. Because the AI companies were unable to develop a truly differentiated, proprietary product line, some companies tried to grow market share by reducing semen prices. Not wanting to lose customers or market share, competing AI companies often responded by lowering semen prices even further. The AI companies were faced with finding ways to reduce costs, and the consolidation movement was underway and continues today. The inability to develop a differentiated product is not due to lack of trying, as the AI companies have invested millions of dollars into their research and development programs in an effort to do just that. However, various biological, scientific, and industry factors have complicated the effort and will be discussed here in more detail.
| SEMEN SUPPLY |
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Bulls are great manufacturers of sperm. A healthy mature bull can produce 40 billion or more sperm cells per week, or more than 2 trillion sperm cells per year. The AI companies normally put approximately 15 million total sperm cells in a straw, although the total cells can vary upwards or downwards depending on the quality of the bulls sperm. Most healthy bulls, if kept on a continuous semen collection schedule, can produce over 100,000 straws of frozen semen per year, and it is not uncommon for some bulls to produce 150,000 or more straws of frozen semen per year. Even at a 33% conception rate, a bull producing 150,000 straws of frozen semen per year could produce 50,000 offspring in 1 yr. The extreme reproductive efficiency of bulls via frozen semen has been a contributing factor to the consolidation and globalization of the AI industry, as relatively few bulls can breed thousands of cows, and it is easy to transport frozen semen to practically anywhere in the world.
| EXPORT GROWTH |
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In the 1970s, Maria Stolzman and colleagues in Poland designed a large-scale FAO breeding trial in Poland in an attempt to quantify differences between strains of Friesians. Ten countries provided semen for the trial: Canada, United States, Denmark, United Kingdom, Sweden, (West) Germany, the Netherlands, Poland, Israel, and New Zealand. The design was for each country to supply 225 to 250 straws of frozen semen from each of 40 nonproven young sires. Results indicated that daughters sired by bulls from North America, Israel, and New Zealand were superior in performance to daughters sired by the bulls from the Western European countries, especially for yield traits. Although some may argue that the experimental design may have been biased (i.e., were the 40 young sires from each country really a representative sample of that countrys Friesian population?), the impact on the AI industry was dramatic. The export of North American Holstein semen around the world accelerated.
The 1980s and early 1990s were growth years for the AI companies. As export markets grew, the AI companies reinvested in their development programs and progeny tested additional bulls. The number of Holstein young sires progeny tested by the major AI organizations in the United States is shown in Figure 1
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| INTERNATIONAL SIRE RANKINGS |
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In 1983, an international research organization was established in Uppsala, Sweden, called the International Bull Evaluation Service (Interbull). The initial objective of Interbull was to develop procedures to collect, standardize, and publish information on the methods used by various countries to calculate sire evaluations. In the early 1990s, efforts were underway to have international evaluations calculated for bulls from all member countries at Interbull using MACE. The United States became a participant in Interbull and in 1995, the United States replaced conversion equations with Interbull MACE for European bulls.
Interbull is still in existence today, and is currently is a joint venture between the International Committee for Animal Recording (ICAR), the European Association for Animal Production (EAAP), and the International Dairy Federation (IDF). Over 40 countries currently are members of Interbull, which provides MACE proofs for production, conformation, and udder health for Ayrshire, Brown Swiss, Guernsey, Holstein, Jersey, and Simmental breeds. Efforts are underway at Interbull to provide MACE for additional health and fitness traits, such as fertility and calving ease.
| SELECTION OF PARENTS |
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The genetic evaluations in the United States for cows and bulls were readily available and easily accessed by all of the AI companies. Breeders supplying bulls to the AI companies often provided bulls to each of the companies. Although the AI companies might have had minor differences in the selection indices for progeny-test bulls, the same maternal and paternal families were used extensively by all of the AI companies. Figure 2
highlights the similarity in average pedigree merit of Holstein young sires that were progeny tested in recent years by the 5 major AI companies in the United States.
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But with more bulls progeny tested, there were subsequently more proven bulls, and the odds of finding a genetic outlier relative to the total bulls sampled became lower given that the bulls were all being sourced from a relatively small, and similar, pool of parents.
| MULTIPLE OVULATION EMBRYO TRANSFER |
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Highly structured MOET programs where the AI companies purchased females and managed the females were established by some of the European AI companies, but not by the AI companies in the United States. In a broad sense, the AI companies in the United States operate very disperse MOET programs, working with cooperator breeders to flush elite females for bulls. A few AI companies in the United States own some females, but no AI organization in the United States has built milking facilities for a structured MOET program, with the exception of Alta Genetics, which has a dairy herd in Canada that has been owned for many years by the principal owner of Alta Genetics. Structured MOET operations require a great deal of upfront capital to build facilities, and the AI companies probably viewed such investments as high risk, especially given the competitive nature of the AI business in the United States.
| PROGENY TEST |
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The investment into expanded progeny-test programs was easy to justify during the rapid growth in export sales during the 1980s and early 1990s, but as the export market softened due to growing international competition in the mid 1990s, the continued expansion in progeny test was less easy to justify from a business perspective.
| GENETIC MARKERS |
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Genetic markers and gene tests have been used extensively to test animals for qualitative traits over the past 25 yr, especially for deleterious recessive genes. The tests have allowed for rapid screening of breeding stock for different recessive genes. The Holstein breed dealt with 2 lethal recessive genes in the last 15 yr that were widespread throughout the breed, first bovine leukocyte adhesion deficiency (BLAD) and later complex vertebral malformation (CVM). Both of these recessives trace back to a popular Holstein bull born in 1974 that was used heavily in global breeding programs, Carlin-M Ivanhoe Bell. For both BLAD and CVM, the gene responsible for the disorder was quickly identified, and a definitive gene test allowed breeders to determine the genotype of their animals. In both cases, AI companies voluntarily discontinued progeny testing young sires known to be carriers of these 2 lethal genes, and the gene frequencies of these lethal genes in the population have or will rapidly decline within a few generations.
Other deleterious and lethal genes have not been as easy to find. For example, the chromosomal region harboring mulefoot in Holsteins and other breeds has been known for many years, but the specific gene has not yet been identified. Chromosome crossover, or recombination, is needed to narrow the region, although the region is small enough that frequency of recombination is rare. However, as long as the entire region is inherited intact as determined by several markers in the region, one can be reasonably confident about the inheritance of the gene. The gene for the Weaver condition in Brown Swiss cattle has also been mapped to a chromosomal region, but the specific gene remains elusive.
For quantitative traits, genetic markers have had minimal, if any, impact on the AI industry to date. Most of the initial data analyzed with genetic markers were production data. The production data were readily available, and in the 1990s, production traits were weighted heavily in the selection indices, and thus, were obvious candidate traits to study. Dairy cattle data were perfectly suited for granddaughter analyses, and the most influential grandsire families were studied. Researchers quickly identified chromosomes of interest for production traits, and certain regions within those chromosomes appeared to include a major gene or genes for production traits. Some regions were specific to individual sire families, whereas others appeared to be significant across families.
Despite the rapid discovery of chromosomal regions of interest for production traits, finding the specific genes has been more difficult. Perhaps gene function associated with quantitative traits such as production is more complex than originally thought. Combining all of the genetic marker data with the population genetics data to arrive at an overall breeding value was also computationally complex.
ABS Global implemented selection of young sires enhanced by genetic marker information, mostly for production traits, from 1997 to 2000. Markers were identified from a granddaughter design and were mostly series of markers upstream and downstream from the hypothesized gene site. This was before dense genotyping, and recombination was relatively common in subsequent generations, making the interpretation of gene inheritance difficult for many of the young sires. The graduation rate (12%) for the 70 young sires selected with genetic markers was the same as for the 500 young sires that were not selected using markers. The early implementation of markers for production traits that covered wide chromosomal regions did not achieve the anticipated objective of higher graduation rates for ABS Global. Conversely, Accelerated Genetics reports that the use of genetic markers in their young sire selection programs has improved their graduation rate.
Applying the genetic marker results to a selection program was complicated by additional factors. Sample sizes were often small. The full-brother with the best genetic markers for production sometimes failed his health test, did not produce semen, or was physically unsound. To validate that the markers were successful required that at least one of the full brothers was progeny tested, and in many cases, only one brother from the litter was progeny tested. This reduced the number of bulls that could be included in the genetic marker subset.
By 2000, most of the AI companies had started to put less selection pressure on production traits so that additional selection pressure could be put on various health, fitness, and conformation traits, such as productive life (PL), somatic cell score (SCS), and udder composite (UC). Although researchers have identified genetic markers for some of these nonproduction traits, there are fewer marker results available for nonproduction traits than for production traits. A challenge remains on how to optimally combine all of the available marker and population data together for both production and nonproduction traits to arrive at a composite breeding value that can be used for selection.
| SELECTION FOR NONYIELD TRAITS |
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In particular, fertility emerged as a growing management challenge in high-producing dairy herds around the world. Days open for Holsteins in the United States has increased by 40 d since 1960, and the genetic proportion of this reproductive decline in days open is estimated at 16 d. The successful selection for production traits appears to have depressed reproductive performance in dairy cattle. Although improved management practices may overcome some of the fertility decline, the data suggest that direct and indirect selection emphasis for reproduction is necessary to slow down the decline in fertility. The linear type trait with the highest relationship with daughter pregnancy rate (DPR) is dairy form. Putting negative selection pressure on extreme dairy form is an initial attempt at using this trait as an indicator trait for improved reproductive performance before the time when the more direct measure of DPR is available.
| INBREEDING |
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Current evaluation and progeny-testing procedures tend to work to the disadvantage of outcross young sires. The outcross sire usually has a lower parent average, so the progeny test must include enough daughters for the young sire to overcome this lower pedigree start point. As more emphasis is placed on lower heritability traits and less emphasis is placed on higher heritability production traits in the genetic indices for overall merit, it will become even more difficult to identify an outcross proven bull through the progeny-test program. Lastly, the response from customers in the marketplace for outcross bulls has generally been lukewarm, not a strong endorsement for the AI companies to risk sampling many lower genetic merit, outcross pedigrees.
| CROSSBREEDING |
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However, several European dairy breeds not commonly found in the United States are now being marketed, primarily to cross on Holstein cows. Among the breeds being imported for crossbreeding are Montbéliard, Normande, and the Scandinavian Red breeds. The growth of crossbreeding in dairy cattle will likely result in the AI companies in the United States developing additional international business collaborations.
| CONCLUSIONS |
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Received for publication September 1, 2004. Accepted for publication October 11, 2004.
| REFERENCES |
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