Protein quality in pig feed (2025)

Nitrogen balance and nitrate contamination of groundwater are still hot topics in pig farming today. In addition, there are crisis-related bottlenecks in the availability of established protein sources, as well as the social demand for the use of local basic feedstuffs to avoid high transport emissions. Proof has been provided both in science and practice that it is possible to reduce the crude protein content without restricting the health and/or performance of pigs. Depending on the rearing phase, the use of synthetic amino acids can save up to 4%-points crude protein.

Alternative, local protein carriers will become increasingly important in future to save production costs and the environment. The future will also see further reductions in crude protein content and the use of precision feeding models for exact supplementation to take resource availability and phase-related requirements into consideration.

Like all mammals, pigs do not have a protein requirement per se, but depend on a sufficient supply of essential amino acids via feed protein to maintain their physiological performance. In addition to the quantity required to meet the demand, the ratio of amino acids to each other is also important.

In terms of research into "ideal protein", the pig has the snout in front. For no species is there more data on phase-dependent amino acid requirements¹. This research shows, however, that the requirement for the first five limiting amino acids (lysine, threonine, methionine + cysteine, tryptophan and valine) is greater in protein-reduced fed pigs than in conventionally fed pigs. This is due to the basic nitrogen requirement for the endogenous synthesis of non-essential amino acids². These also play an important role in the animal as signalling molecules for the regulation of metabolic pathways³.

It is also important to consider the ideal protein concept when selecting the basic feedstuffs. For example, the amino acid profile of maize and soy products often does not match the ideal profile of pigs with regard to branched-chain amino acids. The use of larger quantities of these staple feeds may therefore require the adjustment of the amino acid content in the final compound feed. The amino acid profiles of new basic feedstuffs (by-products, intercrops, on-farm mixtures) must be determined and taken into account in the compound feed formulation.