The dairy industry has been using artificial insemination (AI) to improve genetics and reproduction efficiencies on dairy farms for many decades. Also referred to as “artificial breeding,” the impact of AI has dramatically improved the milk production in dairy cows primarily through the improvement of udder traits. In tandem with the improved milk production and revenue per cow, dairy farmers now routinely use AI as a tool to improve and maintain reproduction efficiencies in their herds throughout the year. The consistent inflow of fresh cows into a dairy herd is one of the most critical elements of maintaining optimal cash flow and profitability for the dairy operation.
AI breeding: Popular choice
The vast majority of U.S. dairy farms now use AI breeding in their herds. The practice of natural breeding by keeping a bull on the farm for breeding has largely been abolished except for the purposes of “clean-up” and heifer breeding – and even those practices are slowly being eliminated. Dairy farmers are realizing the importance of not losing “a generation” from first-calf heifers to an unproven bull and are now breeding their heifers AI as well. As the industry focuses on lowering average days-in-milk on the dairy, fewer of the difficult breeders and long lactation cows are being kept for the clean-up bull to service. Genetics companies have exceled at providing an almost unlimited selection of sires to the marketplace at all pricing points, making the need for having live bulls on the dairy unnecessary.
The improvement of dairy cattle genetics has been ongoing for centuries, beginning with domestication of animals and the establishment of high production breeds such as the Holstein and other breeds with high milk components such as the Jersey. With the advent of technologies for collecting and storing semen, the improvement of milk production has exploded exponentially since the mid-20th century. A report authored by researchers from the U.S. and UK (Oltenacu and Broom, 2010) noted that “…until the mid-1980s, most of the increase in milk production was the result of improved management in nutrition. Since then, genetics has become the major factor due to effective use of artificial insemination (AI), intense selection based on progeny testing of bulls and worldwide distribution of semen from bulls with high genetic merit for production.”
The AI industry was originally born out of the identification and improvement of male heritable genetics transmitted to their daughters who would become milking cows in a dairy herd. Dairy farmers are in the business of making milk with high-producing cows, which means they want many genetically superior cows in their herds and lots of daughters coming from excellent sires. With the development of embryo transfer technology beginning in the 1970s and the perfection of sexed semen identification in the 1990s, the dairy industry has experienced rapid advancement in dairy genetics.
There’s increasing concern, however, that the improved milk production genetics can be taking a toll on other aspects of a cow’s health and physiology. Of primary concern is the tendency toward a reduction in fertility rates in dairy cows as more energy is partitioned to the production of milk. Ironically, as traits improve for milk components and milk production in the pursuit of more profitability per cow, conception rates for lactating cows have declined during the past half-century. For all dairy farms, the pursuit of superior genetics is significantly slowed when cows do not get bred. Oltenacu and Broom go on to report that, “…in the U.S., calving intervals increased from less than 13.0 months to more than 14.5 months and the number of inseminations per conception from 2.0 to greater than 3.5 from 1980 to 2000 in 143 U.S. commercial herds.”
Along with the decreased conception rates, dairy cows are experiencing more metabolic diseases such as mastitis, acidosis and laminitis. Each of these problems can be attributed primarily to the increased stress that comes from increased milk production. As more complete herd health information on each of these diseases is assembled, these data can be used to develop new indexes that will aid in evaluating if cows are genetically predisposed to these health issues as well.
Take off the rose-colored glasses
A straightforward assessment of this situation is that the dairy and genetics industries have been looking through “tinted glasses” as milk production and revenue per cow increases while at the same time other metabolic health issues shorten the cow’s productive life. The dairy industry has, for decades, accepted the average productive life span of a milk cow to be less than four lactations – something that animal welfare activists highly criticize.
The modern dairy industry has been quick to adapt new technologies to improve milk production efficiencies. Artificial breeding has removed the dangers of having live bulls on the farm – dairy herds in the hundreds of cows would need dozens of bulls rotated in and out of the herd all year long to get cows bred while avoiding in-breeding. Artificial breeding has provided an opportunity to create a highly productive and profitable cow – but there’s a downside to that progress as many dairy farmers will admit that their overall reproductive costs have, nevertheless, increased over the years as reproduction and dairy functionality decrease.
With the mapping of the bovine genome in the early 21st century, genomic traits for both bulls and cows can now be tested with the results being part of the decision-making process for bull selection and improving genetics in a dairy herd. The genetic traits of young sires can now be analyzed without them ever having produced a single offspring. Similarly, all the cows on a dairy can be genetically tested, and that genomic data can be used to accelerate genetic improvement on the dairy farm. According to information published by GENEX, progressive dairy farms are using genomic testing to identify the best animals to mate to generate future herd replacements. At the same time genomics can be used by dairy farmers to identify less genetically gifted heifers and those animals can be culled from the herd before they are bred.
Genomics is unquestionably going to change the nature of the AI industry – moving it away from studs owning dozens of sires and collecting millions of units of semen to, instead, investing in daughters and focusing directly on the genetic traits of the female. With the combination of sexed semen, embryo transfers and genomics, the industry is now focusing on acquiring superior daughters that can be bred to superior bulls and flushed for their eggs or embryos. Genomic evaluation, in vitro fertilization and embryo transfer technology will advance to where dairy farmers can flush just their very best heifers, collect those eggs, fertilize them in vitro and implant them into many cows on the farm, thus more rapidly advancing the dairy herd’s genetic improvement. In the future, collecting semen may no longer be necessary with embryo production instead coming from stem cells.
Adapting to the times
The dairy farmer will always need a cow that can remain in the herd for many lactations and produce thousands of gallons of high quality milk in her lifetime while staying healthy. As dairy farmers struggle to stay in business, new technologies such as robotics are changing the playing field. Dairy farms continually require the invention of more advanced equipment to improve efficiencies. Throughout the years the AI industry has worked hand-in-hand with the dairy industry in developing the genetics necessary to improve udder health and deliver the conformation necessary for those cows to function trouble-free in milking parlors and free stalls.
No two dairy farms are the same when it comes to the stage of genetic improvement. This makes the selection of genetics and the breeding of dairy cows a complicated business. Somewhere in the far future, perhaps the dairy industry may finally develop the perfect cow with the perfect set of traits – millions of those cows will be cloned – and the dairy industry will have a one-size-fits-all dairy cow that produces 50,000 pounds of milk per lactation and many pounds of designer proteins and fats while being milked with robots in “cookie-cutter” style parlors. But for now, genetic improvement is a work in progress for breeders and dairy farms.
Bovine genetic advancements
The AI industry has enabled the dairy industry to achieve impressive advancements in bovine genetics in a short period of time. Unfortunately, the AI industry has also become an industry unto itself as big players in genetics jockey for the lead spot in the marketplace with the best selection of genetics and the greatest number of sires and daughters. As with every ultra-competitive industry that consolidates toward oligopoly or monopoly, the AI industry is also moving toward a “one-stop-shop” model as the companies offer packages that include, along with their genetics and reproductive services, herd health and nutrition services.
The largest genetics companies will attempt to corner the market by owning the best genetics. These AI companies are happy to see the dairy industry consolidate into larger and larger herds that will allow them greater efficiencies. Yet the AI industry must remember that they exist for the pleasure of the dairy industry – not the other way around.
Going forward, the industry will still have to address the negative traits associated with cow fertility, health and welfare and continue to tweak their conformation. The AI industry has probably reached a point where continued trait selection for more milk will be counterproductive until fertility and health can catch up. Currently the total performance index (TPI) – endorsed by the Holstein Association USA, Inc., – weights the three primary trait categories of milk production, health and fertility and conformation or durability at 46 percent, 28 percent and 26 percent, respectively. The TPI was updated in 2015 with two additional traits – feed efficiency and fertility index. This is a positive move with an emphasis on building more functional traits into the gene pool as dairy farmers are asking for cows with more commercial functionality.
There’s no question that improved genetics coming from advanced technologies have produced greater efficiencies for the dairy industry, but dairy farmers must remember that they are still in the business of producing milk in a difficult and ever-changing economic environment. The world demand for dairy products will continue to grow. But the dairy farms that are still in business 50 years from now will be milking cows that produce many more gallons of milk in a lifetime to maintain economies of scale.
It appears that from this point forward, dairy farmers will have little choice but to remain partnered with the genetics industry to keep dairy products relevant in an ever-changing marketplace.