Impact of dietary crude protein reduction on performance and feed costs
The reduction of the dietary CP level has no impact on performance as soon as the AA and energy levels are set properly. As Figure 3 shows, dietary CP is not a predictor of performance and so managing risk with this constraint is costly and inefficient.
By using minimum constraints on each EAA, it is possible to optimise a formula without controlling protein per se. The limiting EAA will determine the protein level and dietary CP will be reduced with confidence.
By using at least the minimum constraints recommended in Table 1, and formulating without a minimum CP constraint, substantial costs savings can be realised. The impact on costs savings of formulating by using either a minimum CP constraint or a minimum on each EAA is presented in Figure 4, based on raw materials prices from January 2012 to July 2013.
In this exercise, a Grower formula has been considered (16% minimum CP, 0.85% SID Lys, 9.7 MJ/ Kg Net Energy). When the AA profile (Table 1) is implemented instead of the minimum CP constraint, the feed price is always reduced, from -2 to -13 €/T depending on the month. The CP level decreased from 16% to about 14.5% insuring that the minimum EAA needs were covered. In these formulas, soybean meal was substituted by cereals, rapeseed and/or sunflower meals and feed-use AAs.