Every day, suppliers from companies selling or marketing additives visit nutritionists at local feed companies, veterinarians responsible for nutrition in pig farms, and pig producers. Their aim is to convince that their product is beneficial for our animals and our profit line, and superior to competing products of similar nature. But, given the plethora of similar additives, selecting the right one is a difficult task, even for trained nutritionists, who often prefer not to do anything if they don’t receive a clear message they can trust.

Here, I have the privilege of talking as a consultant working in both sides of the fence: To market or buy any additive, we must understand first how this additive works. To do this, we need to be able to answer the following questions:

  • What is the biological mode of action?
  • What is the animal performance benefit?
  • What is the financial importance?

Let me explain a little more each point above.

Mode of action

First, each additive must have a sound biological basis that makes sense based on common knowledge. For example, we accept that zinc oxide is controlling gastrointestinal microflora in piglets. This makes sense to everybody, as it is a well-documented fact. However, a claim on zinc oxide regarding reproductive performance (for example, more piglets born alive) would have very limited, if any, biological basis.

We should not discount new discoveries in the science of nutrition, but such new findings are rare and require extensive verification before they can become commercially available. So, first, any additive must be presented with a mode of action that makes sense.


Animal performance

Second, the additive must have a proven record of improving performance and/or health. Here, we must distinguish between in vitro (in the tube, or laboratory test) and in vivo (live, or in the animal) tests. For example, some organic acids are active against microbes and this can be proven easily in any laboratory test, but in actual trials with live animals, results are often confusing. I would like to add here that the argument “you should use our additive because XYZ company is using it” is not a valid line of argumentation for any serious additive company.

Health is usually not accounted for along with animal performance, but in truth, sick animals don’t perform. When it comes to young animals, such as piglets and broilers, gut health is the primary target for many commercial additives. Here, we’re faced with a problem: digestive upsets and diarrhea. Additives must be able to solve this problem with a clear-cut result: no diarrhea; anything less than that, and we should keep looking. Sometimes, however, a blend of additives (for example a blend of two or three organic acids) is required for this job, so evaluating each additive individually might not be the right approach.

Financial importance

Third, and most important, is the issue of financial importance. Some additives improve animal performance, for example growth by 2-5 percent. So, if a pig from 5 to 10 kg body weight grows 5 percent more, this means it gains 250 grams more. Is the cost of the additive eaten by the pig less than the price of the extra 250 grams of weight gain? In many cases, this is not, so it does not pay to use such additives. As a general rule of thumb, most additives pay for themselves when animal performance is improved by at least 10 percent – which is rare for most commercial products.

To the cost of using an additive, we must also include the hassle of logistics in ordering, storing and using one more product in our feed mill (for home mixers), so even a small benefit sometimes becomes an unwelcome burden. The feed mill that produces my piglet feeds charges me an extra fee for handling small-volume ingredients that are not mainstream. This certainly makes me think twice when I review my formulas thinking to add (or remove) certain additives.

In brief

Having worked with almost all available additives for the past 15 years, and having followed this industry for 25 years, taught me a valuable lesson. Trust the people, not the products and, above all, use common sense and do a trial. Additives are a great advancement in animal nutrition, but they must be evaluated like everything else.