IMPROVEST Consumer Resource Center

keeping pork delicious

Consumers around the world enjoy pork. On average, it's the most widely consumed meat protein.

Most of us don't realize that meat from mature male pigs (boars) can have an unpleasant aroma when cooked. It's not a safety issue – it's just an objectionable odor.

The smell happens when male pigs reach puberty. Biology kicks in and two naturally occurring compounds are released. These compounds can accumulate in the fat and cause an offensive smell when cooked. Traditionally, farmers have managed these off odors by physically castrating male pigs.

Chances are that you arrived at this site because you read or heard something about this aspect of pork quality or the product that gives farmers an alternative way to manage it. Here we've provided all the "whats," "whys," and "hows" to answer your questions.

Frequently Asked Questions


Why IMPROVEST?

IMPROVEST (gonadotropin releasing factor analog – diphtheria toxoid conjugate) offers farmers a safe and effective alternative to physical castration to manage unpleasant aromas, technically known as "boar taint." Meat from male pigs can have an offensive smell when cooked. While these naturally developing odors are completely safe, research shows that a high proportion of consumers, especially women, can easily detect these offensive odors,[1,2] making their control a necessity to protect the quality experience of eating pork.

You've probably never experienced these unpleasant aromas. Why? Because farmers have controlled them by physically castrating male pigs early in life. Now farmers have a new option for managing this aspect of pork quality.

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What is it and how does it work?

It’s a protein compound that works like an immunization to protect against off odors.

IMPROVEST is an FDA-approved immunological castration product that reduces boar taint. It uses the pig’s own immune system to temporarily provide the same effect as physical castration, but much later in a pig’s life.

It's important to realize that IMPROVEST is NOT a hormone or growth promotant. It's not added to the feed or genetically modified. And, it is not chemical castration. It's a protein compound that creates a temporary immune response to manage the unpleasant aromas.

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Who benefits from the use of IMPROVEST?

For farmers, IMPROVEST offers a safe and effective alternative to physical castration of male pigs to reduce off odors in cooked pork.[3] By eliminating the need for physical castration, the animals grow with all the inherent advantages of intact males. They convert feed to meat more efficiently,[4] and the risk of piglet mortality associated with physical castration is eliminated.[5] Studies also show that following administration of IMPROVEST, pigs are less aggressive than intact males, behaving similarly to pigs raised using the current system.[6,7]
For Americans who eat pork, you can enjoy the same high quality pork and know that it was raised using fewer resources. As intact males, they grow to more of their full potential, converting feed into meat more efficiently.[4] That means they eat less feed, create less manure, and produce more pork.[4,8] Less waste and more pork means a potential incremental reduction in the carbon footprint compared to pigs using the current system.[9]

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Is this used in other countries?

Yes. This type of immunological approach is approved in 60 other countries around the world, including the European Union, Australia and Japan, under the related global brand, IMPROVAC. IMPROVAC has been used successfully by farmers in some countries for more than 10 years.

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What is the alternative to IMPROVEST?

The most widely used alternative is physically castrating male piglets within two weeks of birth (when it is most practical to do). Without some form of control to prevent the substances that create the unpleasant aromas, there is a high risk that some of the meat will be unacceptable to consumers.

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How is IMPROVEST given to pigs?

IMPROVEST is administered via injection just under the skin behind the base of the pig’s ear. IMPROVEST is protein based and must be given this way to create the immunologic response needed to control the unpleasant aromas.

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Is IMPROVEST a hormone?

No. It’s a protein compound that works like an immunization and has absolutely no hormonal activity. It uses the pig’s own immune system to temporarily create the same effect as physical castration in managing the substances responsible for the unpleasant aromas in pork from male pigs.

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Is it safe, are there residues in the meat?

It is safe. There are no residues in the meat from IMPROVEST that could affect human health, according to the FDA. In its approval of IMPROVAC (related global brand), the European Union’s regulatory authority stated that the meat from pigs given IMPROVAC "would not contain any potentially harmful residues" and that the consumption of pork from these pigs therefore "poses no risk to the consumer."[10] (European Public Assessment Report, p. 20)

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How does this impact the environment?

The efficiencies gained by allowing male pigs to grow longer as intact males before IMPROVEST is administered has the potential for an incremental reduction in the carbon footprint.[9]

The environment is of significant importance to the pork industry and its customers.[11] The environmental impact of U.S. pork production is relatively low (0.33% of the total U.S. greenhouse gas emissions).[12] Incremental reductions in these emissions remain a high priority.

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What is gonadotropin releasing factor analog – diphtheria toxoid conjugate?

It’s the generic name for the active ingredient in IMPROVEST. Even though it may sound scary, it’s pretty simple. Let’s break it down:

  1. Gonadotropin Releasing Factor Analog, or GnRF – GnRF is a compound that all mammals produce naturally as they mature, including pigs. IMPROVEST does not contain the naturally occurring GnRF. Rather, it contains an incomplete version of it, i.e. an analog, which makes it inactive.
  2. Diphtheria toxoid (DT) – This is the same as the standard diphtheria vaccine that has been safely used in global childhood vaccination programs since the 1930s. It is simply a protein that contains natural amino acids. It is used as the carrier (conjugate) protein for the incomplete GnRF molecule.
  3. Conjugate – Means "to join together." The two compounds need each other to produce the immunological response in the pig. Together, they act as an immunization to control the substances that create the unpleasant aromas that can occur in the pork from male pigs.
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There’s a lot of concern about autoimmune diseases today. Does Improvest create an autoimmune disease in the pig?

Absolutely not. There is no relationship to autoimmunity for two reasons: 1) the pig is not “mistaking” compounds it naturally produces as foreign, and 2) the action is temporary, which is also not consistent with an autoimmune condition.

In the case of Improvest, the pig’s immune system recognizes the Improvest immunization (which is a protein compound) as “foreign,” or not normally present in its system. As a result, the pig produces antibodies to that complex. This immunological response, which is temporary in nature (it wears off after 10 weeks), is a completely normal response to an immunization.

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Why does IMPROVEST need a prescription from a veterinarian?

The prescribing veterinarian is responsible for informing those who administer the product of its proper use and associated risks. In the event of accidental self injection, reproductive physiology of both men and women, as well as pregnancy, may be adversely affected. It is important to remember that these risks are not associated with eating pork from pigs that have been given IMPROVEST.

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What kinds of questions did FDA require be answered before it approved Improvest?

The FDA considers many questions related to human health before approving any product for use in livestock. The top priority is human safety, so FDA asks whether the compound would be active or could have any side effects if ingested by people, including special populations, like children and pregnant women. They look at these questions from many different perspectives and require many different types of tests. Most of the work is done in animal models, and it includes giving animals extremely high amounts of the product (more than they would ever be exposed to in a lifetime) for a relatively short period of time, as well as for long periods over several generations. If FDA has any remaining questions based on the results of the studies submitted by the sponsor, they require further testing with clear results before either granting or denying approval of the product.
The details of the summary of the work conducted on Improvest are available online from the FDA. A separate independent panel of medical and animal experts reviewed the same data. The panel included experts in pediatric endocrinology, immunology and gastroenterology. The experts concluded, “Based on the data currently available, the panel agrees with the FDA’s conclusion that pork from pigs receiving Improvest is safe for human consumption.”

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What about the health of the pig – did FDA consider the health and comfort of the animals themselves?

Assessing the safety of a given new product in animals is part of the standard FDA animal drug approval process. In the case of Improvest, studies were conducted at up to six times the normal dose and included measurement of the amount of food they consumed, their weight gain patterns and whether there were any reactions at the site of the immunization. Evaluations also included measurements of blood chemistry and other laboratory examinations to check for any signs of possible adverse reactions. FDA was satisfied with the results of these tests, and in fact, observations following extensive commercial use has confirmed that pigs show no apparent discomfort or distress following Improvest use.

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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.
See full Prescribing Information.

IS is NOT
A protein compound A hormone
An immunological product Chemical castration
Temporary effect Genetically modified
Uses the pig's own immune system A growth promotant
Subcutaneous injection

Added to feed

 

Is IMPROVEST safe?

The U.S. Food and Drug Administration has determined that meat from pigs given IMPROVEST is safe to eat.[3] Regulatory authorities in 60 other countries, including the European Union and Japan, have reached the same conclusion for the related global brand, IMPROVAC®.

Why is IMPROVEST important?

IMPROVEST gives farmers a safe and effective alternative to physical castration to manage unpleasant aromas in pork from male pigs. It also creates an opportunity for other efficiencies. By eliminating the need for physical castration, the animals grow to their full intact male potential with all the inherent advantages until the second dose. They convert feed to meat more efficiently, meaning they eat less feed and produce less waste while creating more pork.[4,8]

Advantages documented in global studies include:

  • More food, more efficiently – With the need to feed a growing world population, this approach has the potential for greater protein production with the use of fewer resources.[8]
  • Improved animal health & welfare – Using IMPROVEST eliminates the risks associated with physical castration.[5]
  • Decreased carbon footprint – The efficiencies gained has the potential for an incremental reduction in carbon footprint by as much as 3.6% (measured per kg of pig live weight) vs. pigs raised using the current system.[9]

The environment is of significant importance to the pork industry and its customers.[11] The environmental impact of U.S. pork production is relatively low (0.33% of the total U.S. greenhouse gas emissions).[12] Incremental reductions in these emissions remain a high priority.

As part of the overall commitment to help farmers further reduce greenhouse gases, Pfizer Animal Health has sponsored and had validated by a third party an ISO-compliant global Life Cycle Assessment for the related global brand, IMPROVAC.[9] The LCA measured the environmental impact of allowing pigs to grow longer as intact males with IMPROVAC.

If half the male pigs in the U.S. were raised using IMPROVEST, it would be like removing the CO2 equivalent of 190,000 cars for a year from our roads. [9,13]