Reinforcement of Low-Protein Diets with some EssentialAmino Acids and their Effect on the Productive Performances and some Histological Characteristics of Broilers

The experiment was conducted at the poultry house of the Department of Animal Production - Collegeof Agriculture - Tikrit University for the period between 18/9 and 25 /10/2021. The purpose of thisresearch was to find solutions in order to strengthen low-protein diets with some essential amino acidsand to detect their effect on the productive performance and some physiological characteristics of broilers. In this experiment (300) birds of ROSS 308 strain birds were used, with an average initialweight of 39.7 gm. The birds were divided into five treatments with three replications for eachtreatment (20 birds for each replicate). The treatments were randomly distributed as follows: the first treatment (T1) of the control diet contains crude protein according to ROSS 308 breeding guide, theother four treatments T2, T3, T4, and T5 treatments were subjected to a reduction in the crude proteinby 5, 10, 15, 20% respectively and supported by the amino acids (lysine, methionine and threonine).The results showed that there were no significant differences between the treatments with amino acids and the control treatments regarding body weight at the age of 38 days and the total weight gainexcept for the third treatment (T3) in which the protein was reduced by 10%. No significant effect wasrecorded on the average feed intake when reducing the feed protein by 5% (T2) and the controltreatment (T1). The differences between the control treatment and other treatments concerning thefeed conversion index were no significant. The percentage of the litter decreased whenever the proteinwas reduced. The ratio of the length of the villi to the depth of the crypts was significantly increased for the treatments in which the crude protein was reduced compared to the control treatment.