Effect of dietary supplement of Branched Chain Amino Acids on Production Performance and Some Physiological Traits of Aged Laying Hens

Abstract

The experiment was conducted in order to study the effect of adding a mixture of Branched Chain Amino Acids (BCAA) to the diet of laying hens on productive performance, egg quality traits and some physiological traits during the last stage of the productive life. 180 Lohmann Brown laying hens were bred at 58 weeks of age until at the age of 76 weeks, they were randomly distributed to 18 ground pens, the dimensions of each pen is 1.5 x 2 m, with 10 chickens per pen (as repeated), and after a period of two weeks of breeding, which was considered a preparatory stage for the beginning of the experiment, and at the age of 60 weeks, the hens were randomly distributed over six treatments. , and with three replicates (pen) for each treatment, the first treatment (T1) was fed a standard diet without addition (control treatment), the second treatment (T2), the third treatment (T3), the fourth treatment (T4), the fifth treatment (T5) and the sixth treatment (T6) was fed a standard diet supplemented with 0.5, 1, 1.5, 2, 2.5 g/kg mixture of Leucine, Isoleucine and Valine (mixing ratio 2:1:1), respectively, and the results showed a significant superiority (P≤0.05) for all treatments. Addition of BCAA in the percentage of egg production (HD%) compared with the control treatment, a significant superiority (P≤0.05) was obtained for the two treatments of adding BCAA T2 (0.5g/kg) and T3 (1g/kg) in egg weight, egg mass, feed conversion efficiency and body weight compared with the control treatment, and there was a significant superiority for the two treatments of adding BCAA T2 (0.5g/kg), T3 ( 1 g/kg) in the length of the villi and the depth of the crypts of the intestine compared with the control treatment, and a significant (P≤0.05) was observed for all BCAA addition treatments in the volumetric criterion of antibodies to Newcastle disease virus compared with the control treatment. There were no significant differences between the averages of the experimental treatments in the characteristics of each of blood sugar, uric acid, total protein, cholesterol, and the activity of AST and ALT transporter enzymes, and there was a significant improvement in the level of MDA for all BCAA addition treatments compared to the control treatment. It is concluded from this study that supplementing feed with a sufficient proportion of branched-chain amino acids is beneficial in improving the productive performance, quality traits of the eggs produced and the immune response of laying hens during the last stage of their productive life.