An update on IMPROVEST

In 2011, IMPROVEST (gonadotropin releasing factor analog – diphtheria toxoid conjugate) was introduced to the U.S. market as a Food and Drug Administration-approved alternative to physical castration. It helps manage the issue of unpleasant odors in pork. As the first product in its class of immunological castration, IMPROVEST has generated many questions among producers.

To help producers evaluate the merits of immunological castration for their operations, PorkNetwork recently asked Zoetis to respond to some common questions from producers about IMPROVEST.


How does IMPROVEST work?

IMPROVEST is a protein compound that works like an immunization to temporarily protect against off odors in pork. Use of the product involves a two-dose regimen. The first dose is administered after 9 weeks of age to prime the immunological system of a male pig. Dose No. 2 is administered at least four weeks after the first dose and between three to 10 weeks before the pig is marketed. This second dose temporarily suppresses testicular function as pigs transition to a barrow-like physiology and metabolism for the last few weeks of the finishing period, which fundamentally changes the pig. These two metabolic phases offer opportunities for optimizing production efficiency and carcass characteristics.

What kinds of on-farm trials or product adoption have there been in the United States?

Pork producers, packers and veterinarians have expressed interest in IMPROVEST since it was introduced in 2011. Because it is the first product available in its class in the United States, Zoetis launched the product in a phased approach. Therefore, Zoetis has been working collaboratively with industry members conducting on-farm trials and auditing the implementation process to ensure the product is being used properly and effectively. To date, more than 200,000 pigs managed with IMPROVEST have been harvested in the United States. These pigs were raised in various production systems and processed in 10 different packing operations.

Does IMPROVEST require a significant change in pig flows or management practices?

Immunologically castrated (IC) barrows will fit into current systems. Farms that adopt IMPROVEST will receive comprehensive management training to ensure they have quality assurance and compliance systems in place that clearly define dosing and timing requirements that are critical to controlling off odor that can occur when cooking pork from male pigs. Because the effects of the product are temporary, it also is important that male pigs are marketed within the window (three to 10 weeks after the second dose) when boar taint compounds are not detected by consumers. Accordingly, nutrition programs will need to be optimized to maximize the inherent value of intact males, so producers are strongly encouraged to consult their nutrition advisers to determine the optimum feeding strategy.

IMPROVEST adds cost as a production input. What economic benefits can be achieved for farmers who adopt it?

Pigs managed with IMPROVEST demonstrate consistent and predictable economic results favorable for pork producers. The impact of immunological castration with this product on the performance of male swine has been extensively researched by independent industry experts and their analysis has shown financial advantages, including the potential return of more than $5 per head in net income, for pork producers.

The profit improvement for male pigs is derived from $2 in feed savings, $6.71 for carcass premium and $1.61 in more wean-to-finish net income, which totals $10.32. Additional value is gained through increased feed efficiency and other cost savings as well as from a decrease in castration-related mortality of piglets.

The full cost of utilizing IMPROVEST is estimated to be $5 per male pig, which covers the cost of the product as well as inputs needed for administration and labor. As an added service, Zoetis can handle the administration of the product for an approximate cost of $1 per hog. The cost savings and revenue-generating potential offer producers immediate return on their investment and help to position them for stronger financial success.

What is the impact of heavier market weight hogs in the United States compared with lighter weight hogs in other countries?

The use of IMPROVEST is not influenced by market weight; therefore, it has been used successfully in different production systems around the world. In Brazil where Vivax (the Brazilian brand of IMPROVEST) has been used for more than 6 years, carcass weights have increased over time and now are similar to those in the United States. IMPROVEST also is considered size-neutral and has been found to bring economic, environmental and nutritional benefits to farms of any size.

Are there any export restrictions on IPROVEST?

No. The introduction of IMPROVEST into the U.S. market builds on extensive product use and on-farm trials conducted around the world. The product is marketed as IMPROVAC internationally and has received regulatory approval in more than 60 countries. Widespread adoption is especially noteworthy in top U.S. pork export markets, such as the EU, South Korea, Russia, China, Japan and Mexico.

With the attention animal agriculture is receiving today, what research suggests that consumers will accept this new technique?

Gauging consumer awareness and attitudes on the issue of castration was an important step in the product's development in the U.S. While consumers have a relatively low level of awareness about the practice of castration and the issue of boar taint, their attitudes about alternative methods of castration were positive. Extensive market research and real-life experience in Europe indicate consumers prefer the immunological alternative to physical castration, suggesting the social benefits outweigh any concerns with the technology.

Does Zoetis plan to position IMPROVEST with consumers?

No. Zoetis does not plan to communicate proactively to consumers about IMPROVEST. Zoetis is and always has been committed to marketing IMPROVEST directly to producers and packers as a production option. With that, Zoetis has worked with independent experts to evaluate the use of the product on U.S. pig farms to understand the economic, nutritional and environmental benefits that are associated with its use. We believe producers will choose to use it in their production systems because of the economic benefits.

What seems to be the most common misperception about IMPROVEST in the United States?

Initially, IMPROVEST was thought to be a feed-cost-saving technology. However, the major benefit to producers is to market more pounds of pork with a similar feed cost, thereby increasing revenues relative to costs. A panel of independent economists determined that producers who adopt IMPROVEST can expect the optimum market weight of their animals to increase by an average of about 10 to 12 pounds per head on a live-weight basis (4 to 6 pounds per carcass) vs. physically castrated (PC) barrows. This outcome is consistent under a variety of cost and price scenarios. Furthermore, male pigs managed with IMPROVEST will attain this added weight without any additional days on feed, and the carcass will command a slightly improved premium value primarily due to increased uniformity.

What are the e­ffects on feed conversion and average daily gain after using IMPROVEST?

A summary of 12 U.S. trials demonstrated that IC barrows possessed a feed conversion ratio 8.41 percent lower than PC barrows while holding a 4.28 percent average daily gain advantage. This adds up to IC barrows weighing 10 to 12 pounds more at market, with a carcass 4 to 6 pounds heavier all without adding days to the grow-out period. Do pigs managed with IMPROVEST have leaner bellies?

Carcass characteristics and belly quality have been closely studied with the introduction of IMPROVEST into the U.S. pork industry. Results show that achieving optimum belly characteristics is possible with IMPROVEST when proper management practices are followed, specifically as it relates to the timing of the second dose. Seven to 10 days after the second immunization, IC barrows increase their feed intake, slightly reduce lean tissue gain and increase body fat deposition. This increase in body fat deposition is important to preserve belly quality in terms of fat content and fatty acid composition. Belly quality can be increased by extending time between the second immunization and slaughter; for pigs fed corn-based diets, it is suggested to have at least five weeks between the second immunization and slaughter for the first cut out of the barn. Producers should work with their nutritionists to determine the best feeding strategies.

Are there safety risks to employees who administer IMPROVEST to pigs?

With the administration of any injectable animal health product, employee safety is paramount. With IMPROVEST, Zoetis offers producers a complete training program and verification process to ensure that quality assurance protocols are met. This support can be in the form of Zoetis employee technicians, who are trained and certified to administer the product, or Zoetis training and certifying your staff to administer the product.

Important Safety Information: Pregnant women should not administer IMPROVEST. Women of childbearing age, as well as men, should exercise extreme caution when administering this product. Exercise special care to prevent accidental self-injection because of negative effects on reproductive physiology in both men and women. However, there is no risk associated with consuming pork from animals administered this product. IMPROVEST should not be used in female pigs, barrows or male pigs intended for breeding.

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