ABSTRACT This experiment evaluated the effects of Saccharomyces cerevisiae (S. cerevisiae) and citric acid on production performance, egg quality, intestine histomorphology, and avian β-defensin 1 and 2 (AvBD 1 and 2) gene expressions in laying Japanese quails. A total of 400 48-day-old quails were randomly assigned to a 2×2×2 factorial arrangement of treatments with 5 replicates (each containing 10 quails) for 7 weeks. Variable factors consisted of S. cerevisiae (0 and 100 mg/kg diet), citric acid (0 and 5 g/kg diet), and Virginiamycin (0 and 50 mg/kg diet). At the completion of the trial, one bird per replicate was randomly killed, and jejunal tissue samples were removed to evaluate intestinal morphometric characteristics. Samples were taken from the midpoint of the jejunum to measure the gene expression of AvBD 1 and 2. Dietary inclusion of both S. cerevisiae and citric acid resulted in increased egg weight, egg mass, reduced feed intake, and improved FCR (p<0.05). The addition of S. cerevisiae to diets containing citric acid reduced feed intake, increased egg weight, and improved FCR (p<0.05). Shell weight and shell thickness were increased in birds fed each of S. cerevisiae and citric acid supplements (p<0.05). Dietary S. cerevisiae and citric acid similarly increased intestinal villus height, width, surface area, and the villus height to crypt depth ratio (p<0.0001). Results showed that AvBD 1 and 2 genes expression were up-regulated on quails fed S. cerevisiae-supplemented diets (p<0.0001). In conclusion, these results suggest that supplementation of S. cerevisiae and citric acid as functional feed additives either alone or in combination could be a potential alternative to antibiotics in the diet of Japanese laying quails.

Abstract An experiment was conducted to investigate the effects of hydroalcoholic extract of Withania coagulans (WC) fruit and 1.25-dihydroxycholecalciferol (1.25-(OH)2 D3) on bone mineralization, mechanical and histological properties of male broiler chickens at 21 and 42 d of age. A total of six hundred male day-old Ross 308 broiler chickens were randomly distributed according to a completely randomized experimental design in a 2×3×2 factorial arrangement with 12 treatments of five replicates of 10 birds each. Treatments consisted of two basal diets (positive control with adequate Ca level and negative control with 30% less Ca), three levels of WC (0, 100, or 200 mg/kg diet), and two levels of 1.25-(OH)2 D3 (0 or 0.5 µg/kg diet). Birds were housed in floor pens. The diets were fed ad libitum from one to 42 days of age. On day 21 and 42, one bird per replicate was sacrificed and its tibiae were removed. Both Ca and P retention increased when dietary Ca level was reduced (p<0.001). The addition of 200 mg WC/kg to positive control diet increased Ca retention (p<0.01). Except for tibia diameter, no significant main effects of experimental treatments were observed on tibia physical characteristics or on bone mineralization. The diet with 30% Ca reduction decreased tibia diameter at 42 days of age (p<0.05). The dietary addition of 1.25-(OH)2 D3 increased tibia fracture energy, width of tibia mineralized zone, and serum Ca at 42 days of age (p<0.05). At 21 days of age, supplementation of 100 mg WC/kg increased cortical thickness (p<0.05). At 42 days of age, supplementation of 100 mg WC/kg increased tibia shear force (p<0.05) and fracture energy (p<0.01). The results of this experiment showed that supplementation of 100 mg/kg hydroalcoholic extract of WC fruit increased tibia cortical thickness, shear force, and fracture energy.