Increasing the Digestive Efficiency of Local Raw Materials with Enzymes PART 3
Optimizing Amino Acids and Protein Digestibility In Diets Containing Soybean Alternatives
With soybean prices continually increasing, producers are looking to incorporate alternative protein-sources into swine diets. Among the main alternatives are rapeseed meal and sunflower meal. These are rich in protein but also less digestible than soybean meal. NIR analysis shows they contain:
More fibre/NSP
Different types of NSP
A portion of nitrogen trapped in the fibre fraction (neutral detergent fibre)
More cellulose and pectin; addition of 5–7% rapeseed and sunflower meal as a replacement for soybean in piglet diets increases the pectin content by 30–50% and cellulose content by 10–20%.
In diets containing these alternatives, a different suite of enzymes is needed to maximize digestibility and maintain the nutritional value of the diet. This may include xylo-glucanases to breakdown the xyloglucan (NSP) network, pectinases to break down the pectic polymer matrix and cellulase to break down cellulose in the cell walls. Research in growing pigs has shown that the combination of pectinase, cellulases and hemicellulases present in improved protein availability and thereby increased daily gain and feed conversion ratio when added to diets containing 314 or 18% of rapeseed meal, to levels comparable to a conventional diet containing 11% soybean meal.
What About Sustainability?
Finally, the use of enzymes in swine diets containing alternatives can improve the sustainability of production. This is evident from numerous studies showing the environmental impact of added enzymes is small compared to the feed component that they replace. In this context it is clear enzymes can contribute to reducing both the carbon footprint of the feed (by enabling lower inclusion of raw materials or replacement with (local) alternatives) and that of the animal during growth (by increasing feed efficiency and reducing emissions). Quantifying these benefits and developing more sustainable diets with enzymes are major areas of future research.
Conclusions
Market pressures and an increasing interest in sustainability are driving pork producers to consider increased inclusion of (locally available) alternative raw materials in swine diets. This is fueling science and research into how enzymes may be useful in improving the digestibility of such alternatives to maintain feed efficiency. Nowadays, a precision-nutrition based approach is being adopted that involves use of NIR analytics to understand the detailed composition (and variability) of alternatives and other ingredients in the diet, the mapping of available substrates to enzymes, and optimization of the diet formulation. This new way of using enzymes in diets containing alternatives is effective and can support both feed efficiency and sustainability goals.
