Due to little choice of ingredients we have in SA, there is still potential to extract and optimise the value of maize and soybean meal (SBM). The focus on SBM still revolves around optimising processing conditions to reduce the effect of antinutritional factors, mainly trypsin inhibitors. There is still an opportunity to embark on characterizing and quantifying the value and the impact of SBM carbohydrates. To improve the efficiency of utilization of SBM carbohydrates, concerted research effort is necessary to understand factors that limit their digestion and absorption and interaction with gut microbiota in the digestive tract. Similarly, there is still a lot required to profile the quality of sunflower meal and the fibres fractions as alternative source of protein.
Although maize is considered to be good digestible cereal as energy source, there is some evidence to suggest that a proportion of starch in maize can be described as being resistant to digestion limiting the energy value of maize. This can be ascribed to the occurrence of the varying contents of resistance starch (RS). In addition, variation in the concentration of antinutritional factors such as amylase inhibitors and phytate influence the nutritional value and digestibility of maize.
Understanding dietary carbohydrates and antinutritional factors and variation of SA ingredients will improve the way formulate feeds to better deal with interactions between accessible/digestible nutrients, undigested components (substrates), gut microbiota and the host.
There is a wealth of scientific reports detailing the role of feed enzymes in reducing the negative effects of antinutritional factors and their impact on gut health and for improving nutrients digestibility of ingredients by acting on undigested components. Most these undigested dietary fractions cannot be digested by animal endogenous enzyme, therefore provide an optimal environment for pathogenic bacteria overgrowth in the gastrointestinal tract (GUT). To further improve GUT health without the use of AGPs, and reduce negative interactions caused by pathogenic bacterial proliferation in the GUT, we see the innovation of new enzymes classified as "health enzymes". The new class of enzymes called exogenous "Muramidase" hydrolyses peptidoglycans (PGNs) from the bacterial cell debris' in the GUT. PGNs from bacterial cell debris' is reported to have a negative effect on the gut and reduces the efficiency of nutrients absorption. Enzymes can be positioned as one of the important solutions to implement in feeding AGP free diets to livestock but cannot be positioned as the only potential replacement for AGPs. See review articles by Huyghebaert.
Huyghebaert et al, 2011. An update on alternatives to antimicrobial growth promoters for broilers. Journal Veterinary Journal. 187: 182–188