Effect of enriched nucleotide supplement on growth performance and immune responses in broilers

This research was conducted to evaluate the effects of different levels of nucleotide supplementation on growth performance and immune responses of broiler chickens. An experiment was conducted as a completely randomized design using 300 day-old male chicks, were divided into five treatments with five replicates and 12 chicks in each replicate. The treatments consisted of the basal diet without additives (control), the basal ration + 500 g/ton of probiotic CloSTAT, basal diet + 400, 500 and 600 g/ton enriched nucleotide supplement, respectively. Daily feed intake, daily body weight gain and feed conversion ratio were measured at the end of each period. Humoral and cellular immunities were evaluated by intramuscular injection of sheep red blood cell (SRBC) and intradermal injection of phytohemagglutinin-P (PHA-P) in wing, respectively. The results indicated that all levels of the nucleotide reduced the daily feed intake (89.7, 83.3 and 79.4 vs. 98.2 g, respectively) and improved feed conversion ratio (1.67, 1.62 and 1.62 vs. 1.93, respectively; P<0.05).  On day 28, probiotic CloSTAT and 400 and 500 g/ton of nucleotide had higher levels of total anti-SRBC (5.20, 6.60 and 6.90 vs. 3.20) and IgM (2.60, 3.20 and 2.20 vs. 0.90; P<0.05). On day 35, the treatments of 400 and 500 g/ton nucleotide have higher total anti-SRBC (6.60 and 6.10 vs. 3.80 and 4.50), IgG (3.50 and 3.30 vs. 2.10 and 2.50) and IgM (3.10 and 2.80 vs. 1.70 and 2.00) than the control group and probiotic CloSTAT (P<0.05).  Cell immunity in response to PHA-P injection was not affected by treatment groups (P>0.05). It is concluded that consumption of 400 and 500 g/ton enriched nucleotide supplement in the diet has beneficial effects on performance and immune responses of broiler chicks.