Effect of Dietary Inclusion of Sodium Bicarbonate on Digestibility of Nutrients and Immune Response in Caged Layers During the Summer

ABSTRACT The aim of this project was to investigate the effect of dietary inclusion of sodium bicarbonate (NaHCO3) on nutrient digestibility and immune response of caged layers during summer when the temperature exceeds 40 ˚C. For immune response trial, White Leghorn layers (n=160; 24 weeks old) were purchased from a poultry farm and were divided into five treatment/diets groups (4 replicate/treatment). Diet A, was without NaHCO3 and served as control whereas, diets B, C, D, and E contained 0.5, 1.0, 1.5 and 2.0% NaHCO3, respectively. All these birds were vaccinated against Newcastle disease (ND) virus at the start of the experiment and thereafter with one-month intervals. Blood samples were collected from two birds/replicate at 10 days post vaccination each time to check antibody titer against ND virus. For digestibility trial, fecal samples were collected (6 layers/treatment group) at the start of the 37th week of age for two days, at 3 hours interval. Results revealed that immune response against ND virus 10 days post vaccination after 1st, 2nd and 3rd month was significantly (p