Most dietary protein is hydrolyzed and absorbed in the small intestine and foregut via endogenous enzymes into amino acids and peptides. There are several factors that influence protein digestibility, these include quality of protein, absorptive capacity of the animal, and efficacy of endogenous and exogenous enzymes. Any protein that is not digested and absorbed in the small intestine passes to the hindgut and becomes residual protein. Residual protein consists of undigested protein from the foregut as well as endogenous protein and recycled systemic protein. This hindgut protein is broken down by microbiota into amino acids and by a series of processes leads to hindgut fermentation causing the release of nitrogenous toxins or outputs such as short-chain fatty acids, branched chain fatty acid, NH4+ (hydrogenated ammonia), and sulfur compounds. Nitrogenous toxins are harmful to the animal and can result in disrupted intestinal barrier, increased susceptibility to enteric stress, increased nitrogen emissions (environmental ammonia), and reduced animal welfare.
There are strategies that can be implemented to mitigate toxicity effects including the reduction of residual protein and redirecting nitrogen in the hindgut. By improving protein utilization in the foregut or small intestine, less protein will pass to the hindgut, therefore reducing residual protein. This can be done by phase feeding protein levels, formulating low protein diets, using synthetic amino acids, and/or utilizing exogenous enzymes such as a protease to improve protein and amino acid digestion and absorption. With the help of endogenous enzymes, exogenous enzymes can maximize protein digestion and decrease the amount of residual protein reaching the hindgut. Even with these strategies there is still some protein present in the hindgut.
In the hindgut a precision biotic (tailored oligosaccharide) can redirect the negative outcomes of residual protein. For example, increasing short chain fatty acid production (i.e. butyric acid) and reducing the amount of ammonia and other inflammatory compounds. This strategy can improve pathways for nitrogen utilization and decrease the negative effects of nitrogenous toxins. By redirecting nitrogen, enteric stress is decreased. This strategy also has an impact outside the animal by reducing nitrogen compounds (i.e. ammonia) into the environment and improving litter conditions and bird welfare.
There are opportunities in both the foregut and the hindgut to redirect or re-utilize excess protein and nitrogen. By improving these biological processes, the negative outcomes of ammonia and nitrogenous toxins can be reduced to benefit the animal and its environment.