The effects of diets with reduced levels of energy, lysine, and methionine and different dietary forms of these amino acids on non-specific immunity, natural resistibility, and nutrient digestibility in broiler breeder hens
In two trials on hens of preparental maternal lines of broiler cross Smena-9 (Cornish line SM5 and Plymouth Rock line SM9) the effects of diets with reduced by 5% levels of energy, lysine, and methionine and different dietary forms of these amino acids on non-specific immunity, natural resistibility, and nutrient digestibility were studied. It was found that lysin in the form of sulphate and liquid hydroxy-analogue of methionine are highly available for the hens, and their use in the diets resulted in the indices of non-specific immunity and resistibility (lysozyme and bactericidal activity of blood serum, indices of phagocytosis) as well as digestibility and retention of dietary nutrients and availability of dietary amino acids close to that in hens fed synthetic DL-methionine and lysine monochloride. The activity of hydroxy-analogue of methionine was found to be 88% of the activity of DL-methionine.