Maria Villagrasa & Fernando Diaz
Hydrolyzed feather meal is obtained from grinding fresh feathers that have previously been treated with water vapor under pressure. It is a feedstuff with high crude protein content (CP; 92%) which can be used as a source of rumen undegradable protein in dairy cow rations.
One limitation to its use in animal diets however is its imbalance in essential amino acids. It contains a very high concentration of cysteine and is also high in threonine and arginine, but deficient in methionine, lysine, tryptophan and histidine. Therefore, if a suitable supplement is not included in the diet feeding hydrolyzed feather meal can lead to amino acid deficiencies.
The use of protected amino acids is an option to increase the total flow of limiting amino acids in the metabolizable protein such as lysine (Lys) and histidine (His). This option allows to improve the use of amino acids by the cow as well as reduce the urinary excretion of N and ammonia in manure.