Feeding intact proteins, peptides, or free amino acids to monogastric farm animals

Abstract

For terrestrial farm animals, intact protein sources like soybean meal have been the main ingredients providing the required amino acids (AA) to sustain life. However, in recent years, the availability of hydrolysed protein sources and free AA has led to the use of other forms of AA to feed farm animals. The advent of using these new forms is especially important to reduce the negative environmental impacts of animal production because these new forms allow reducing the dietary crude protein content and provide more digestible materials. However, the form in which dietary AA are provided can have an effect on the dynamics of nutrient availability for protein deposition and tissue growth including the efficiency of nutrient utilization. In this literature review, the use of different forms of AA in animal diets is explored, and their differences in digestion and absorption rates is focused on. These differences affect the postprandial plasma appearance of AA, which can have metabolic consequences, like greater insulin response when free AA or hydrolysates instead of intact proteins are fed, which can have a profound effect on metabolism and growth performance. Nevertheless, the use and application of the different AA forms in animal diets is important to achieve a more sustainable and efficient animal production system in the future, as they allow for a more precise diet formulation and reduced negative environmental impact. It is therefore important to differentiate the physiological and metabolic effects of different forms of AA to maximize their nutritional value in animal diets.

The “ideal protein” concept is not ideal in animal nutrition

“…Readers are referred to recent excellent reviews on this topic. 62,80 The revision of the “ideal protein” concept by the integration of AASAs can improve AA provision in the diets of animals. Because animals have dietary requirements for AAs but not protein, 2 a term “optimal ratios and amounts of all proteinogenic AAs” is scientifically more accurate and practically more useful than the “ideal protein.” In the case of carnivorous species, taurine should also be provided in their diets to prevent damage to the eyes, heart, and other organs.…”

“…Of note, there has been increasing interest in the use of protein hydrolysates (including small peptides) and functional AAs (in the crystalline or liquid form) to feed animals. 2,62…”

“…The "ideal protein" concept has greatly advanced the field of swine and poultry protein nutrition over the last four and six decades, respectively, resulting in the practice of dietary supplementation with crystalline EAAs to improve the growth, feed efficiencies and productivity of pigs and poultry. 14,37,[58][59][60][61][62] This nutritional concept has also been adopted by the dairy cattle industry to provide rumen-escape protein or EAAs for high-producing cows 14 and highlighted in the literature concerning the nutrition of other farm animals, including fish and crustaceans. 63 In addition, the "ideal protein" concept is now also used to feed zoo 64 (e.g.…”

The Effect of Amino Acids on Production of SCFA and bCFA by Members of the Porcine Colonic Microbiota

“…Functional amino acids supplementation is believed to be beneficial in challenged animals not only by regulating intestinal barrier, oxidative stress, and immunity but also by modulating microbiota which in turn can improve host health. Amino acids can also reach the colon given that crude protein digestibility is only between 70-90% (thus resulting in 10-30% amino acids reaching the large intestine) [2]. These latter effects were firstly described in mice where arginine or glutamine supplementation at a high dose was associated with an increased population of Lactobacillus in the jejunum [3,4].…”

The Effect of Extruded Feed Additives with Balsamic Poplar Buds on Productivity of Dairy Goats

“…Animal feeding is an important part of animal husbandry. An innovative approach in science and technology, opens up many opportunities for improvements in feed production and animal feeding (den Hartog and Sijtsma 2013;Guo et al 2022;Eugenio et al 2022;Shah et al 2022).…”