Additives remain relative despite global financial crises and expensive ingredients. Daily, representatives from additive suppliers visit nutritionists and purchasing agents at local feed companies, veterinarians responsible for nutrition at farms, and, of course, animal producers. Their job is, naturally, to convince that their products are beneficial for the animals and profitable for the farmer, and are superior compared to competing products of similar nature. Given the plethora of available additives and multitude of research reports, selecting the right additive can be a daunting task.
To evaluate any type of additives, I use the following three questions as a starting point:
- What is the biological mode of action?
- What is the benefit in terms of animal performance (growth, health, productivity, etc.)?
- What is the financial outcome from using this additive?
Let us discuss each point in detail.
1. Each additive must have a sound biological basis that makes sense based on common knowledge. For example, we all accept today that zinc oxide controls gastrointestinal microflora, and through this action it improves animal health and increases growth performance in piglets. We also accept that broilers fed feed heavily contaminated with mycotoxins will benefit from a suitable anti-mycotoxin agent. However, a claim on zinc oxide regarding reproductive performance (for example, more piglets born alive) would have very limited (if any biological basis). The same applies for a claim on enhanced egg weight by feeding an anti-mycotoxin agent when diets are practically devoid of any mycotoxins. Of course, here, 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 applicable.
2. The additive in question must have a proven record of improving performance and/or health. Here, we must distinguish between in vitro (laboratory test) and in vivo (live animal) tests. For example, some organic acids are active against microbes and this can be proven easily with a laboratory test, but in actual trials with live animals, results have often been disappointing. This probably has to do with the required dosage, which needs to be very high to be effective under practical conditions. In brief, each additive should be accompanied by a research dossier that undisputably supports any claims made above, not only through in vitro, but also through in vivo tests, under a number of practical conditions.
3. Last but highly important is the issue of financial outcome, or as frequently termed “return on investment.” Some additives improve animal performance, for example growth by 5 percent. In this case, 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 per pig less than the price of the extra 250 grams of weight gain? In many cases, this is not so, and as such it does not pay to use the additive. As a general rule of thumb, most additives pay for themselves when animal performance is improved by at least 10 percent. 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, so even a small benefit sometimes becomes an unwelcome burden.