Use of additives
Assessing feed additive efficacy requires precisely identifying factors that limit technical and economical performances of the farms and therefore being able to choose the most adequate product which is able to target these points. If the request is not precise enough, the choice of the additive can lead to a non-adapted product. For example, improving FCR is a general aim. It is important to know why the FCR is poor. If it is due to bad digestibility of raw materials, the choice will be orientated to the use of enzymes. If linked to bad absorption of nutrients, products acting on gut mucosa protection or gut flora regulation would be more suitable.
Moreover, according to users, the main problem regarding the use of additives is variability of the results. However this variability is not specific to additives currently on the market. Antibiotic additives are facing the same problem.
Could part of this variability be linked to the fact that additives are tested with too general expectations or in conditions that do not correspond to their mode of action? To correctly evaluate an additive, it is essential to know for which objective it is being tested for. This is obvious for additives whose nature and function are the same: thus we expect from a coccidiostat a control of coccidiosis. Users expect from an enzyme a better digestibility of some raw materials or nutrients. However, when talking about vegetal extracts, it refers only to the nature of the additive and does not give any indication on its function. Consequently, it is necessary to know the exact composition in vegetal active molecules to conclude on the function of the product and on the adapted context to test it to get optimum effects.