Effects of In ovo taurine administration on hatchability, growth performance, hepatic gene expression, plasma metabolites, and antioxidant status in broiler chickens

As the growing period shortens, researchers are developing innovative strategies to combat this physiological burden during embryonic development. This study aimed to investigate the effects of in ovo taurine (TAU) feeding to the 17.5 days old Arbor Acre embryos. Fertilized eggs (n=360) were equally distributed into 5 treatments: (i) Uninjected control (UCON); (ii) 0% TAU group (or distilled water injected control, 0TAU); (iii) 1% TAU group (1TAU); (iv) 3% TAU group (3TAU); and (v) 5% TAU group (5TAU). At hatch, organ weights did not vary significantly. Liver weight at 28th day of rearing was significantly higher in the 3TAU group (p = 0.028). A linear increase in body weight on the 21st (p = 0.004) and 28th (p = 0.009) days of age was recorded. The relative length of duodenum, jejunum, ileum, and cecum (p < 0.05) were linearly decreasing with the higher dose of TAU injected. Plasma free radical scavenging activity (DPPH-RSA%) of 3TAU at hatch was the highest (p = 0.043), and antioxidant balance was highest in the 3TAU group at day 28. Total plasma protein, albumin, and albumin: globulin ratio in plasma were reduced by TAU treatment (p < 0.05) on day 28. The hepatic expression of nuclear factor erythroid 2-related factor and catalase increased at day 28 compared to day 0 (p < 0.05). Genes such as ten-eleven translocation enzymes (TRT) 1∼3 (p < 0.05) were downregulated at day 28, suggesting age-related modulation of demethylation-related gene activity. However, 5TAU showed higher expression of these genes compared to 0TAU (p < 0.05). Pearson’s correlation analysis for the studied genes revealed positive correlation among (i) DNA-methylation genes and antioxidant enzymes, (ii) DNA-demethylation and NADPH oxidases. Hence, 3% TAU fed in ovo might be beneficial to improve the growth and antioxidant capacity of broilers.