Effect of Dietary Nucleotide Supplementation on the Immune Response of White Leghorn Layers

Immune competence, as indicated by the levels of antibody titres, represents a vital component in the production of layer poultry. It contributes significantly to enhancing disease resistance, thereby reducing production losses associated with infections and promoting overall performance in poultry farming. An experiment was conducted to evaluate the effect of dietary nucleotide supplementation on the immune response of White Leghorn layers, with a specific focus on antibody titre against sheep red blood cells (sRBC) over a 40-week period. A total of 160 birds, aged 15 weeks, were randomly assigned to four dietary treatments (T1: basal diet for layer chicken phase I (BD), T2: BD + 0.5 g nucleotide/kg, T3: BD + 0.75 g nucleotide/kg, T4: BD + 1.0 g nucleotide/kg) in a completely randomized design, with five replicates per treatment and eight birds per replicate. Following a two-week adaptation period (15–16 weeks) for nucleotide supplementation, the birds were fed experimental layer diets from 17 to 40 weeks of age. The humoral immune response to sRBCs was assessed using the haemagglutination (HA) test. Blood was collected at 15 weeks of age from six birds in each treatment group to quantify the pre-inoculation titre value. A primary and booster dose of 25% sheep RBC suspension was administered at 17 weeks of age, followed by additional blood collections at three-week intervals from 18 to 40 weeks of age to estimate the humoral immune response. The results showed no significant differences in antibody titres during the early weeks (15–27 weeks of age). However, significant improvements in antibody titres were observed in T2, T3, and T4 groups at 36 and 40 weeks, with these groups exhibiting significantly higher titres (p<0.05) compared to the control group (T1). Dietary supplementation with nucleotides at 0.5, 0.75, and 1.0 g/kg of diet enhanced humoral immunity, as indicated by elevated antibody responses in later weeks. These findings underscore the importance of dietary nucleotide supplementation, to strengthen the immune system in layer birds. Enhanced antibody titres, particularly in later production phases, contribute to improved disease resistance and sustained productivity, emphasizing the value of nutritional interventions in optimizing health and performance in commercial layer production.