Modified dietary fiber from cassava pulp affects the cecal microbial population, short-chain fatty acid, and ammonia production in broiler chickens.

The objective of this study was to investigate the effects of modified dietary fiber from cassava pulp (M-DFCP) supplementation in broiler diets on cecal microbial populations, short-chain fatty acids (SCFAs), ammonia production, and immune responses. A total of 336, one-day-old male broiler chicks (Ross 308) were distributed over 4 dietary treatments in 7 replicate pens (n = 12 chicks) using a completely randomized design. Chicks were fed the control diet and 3 levels of M-DFCP (0.5, 1.0, and 1.5%) for an experimental duration of 42 d. The M-DFCP contained total dietary fiber (TDF), soluble dietary fiber (SDF), insoluble dietary fiber (IDF), cello-oligosaccharides (COS), and xylo-oligosaccharides (XOS) of approximately 280.70, 22.20, 258.50, 23.93, and 157.55 g/kg, respectively. The 1.0 and 1.5% M-DFCP supplementation diets showed positive effects on stimulating the growth of Lactobacillus spp. and Bifidobacterium spp., enhancing SCFAs (acetic, propionic, butyric acid, and branched SCFAs) and lactic acid concentrations during growing periods. Broilers fed 1.0 and 1.5% M-DFCP also exhibited a significant increase in caecal Lactobacillus spp. and lactic acid concentrations during the finisher period as well. In addition, M-DFCP also reduced cecal digesta and excreta ammonia production in broilers over both periods (0-21 and 22-42 d of age). However, M-DFCP did not exhibit any effect on total serum immunoglobulin (Ig) or lysozyme activity. In conclusion, this study shows that M-DFCP can be used as a dietary fiber source in broiler diets, with a recommended level of approximately 1.0%.

Growth performance and accretion of selected amino acids in response to three levels of dietary lysine fed to fast- and slow-growing broilers.

Literature data indicate that feed intake is sensitive to the dietary Lys content particularly in fast-growing birds. From a conceptual and a practical viewpoint, an interaction between genotype (i.e., fast-growing vs. slow-growing birds) and dietary Lys content is of interest, but it needs confirmation owing to a dearth of studies addressing this issue. A study was conducted with 266 Cobb 500 birds and 266 Thai native crossbreed birds serving as models for fast-growing broilers (FGB) and slow-growing broilers (SGB), respectively. Within genotype, chicks were randomly allocated to diets containing either a high (H-LYS = 1.36%), medium (1.17%), or low Lys (1.01%) content. Growth performance and the accretion of protein and selected amino acids were determined in birds from 1 to 21 d of age. Treatments were arranged in a factorial design with 6 replications/treatment. Low Lys vs. H-LYS caused a 42.1% lower feed intake in FGB (P < 0.001), but not in SGB (P = 0.596). The feed conversion ratio (FCR (g feed/g BW gain)) was lowest in FGB (P < 0.001) and increased with decreasing dietary Lys contents (P < 0.001). The Lys induced increase in FCR, however, was more pronounced in SGB (P = 0.025). The absolute protein gain (g/bird) was influenced by the Lys content of feed and decreased by ∼54% and ∼23% in FGB and SGB, respectively (P < 0.001). The efficiency (% of intake) of protein accretion was found to be greater in FGB (P ≤ 0.001) and decreased with decreasing dietary Lys (P ≤ 0.001). The efficiency of Lys accretion was found to be negatively affected by the dietary Lys content in FGB (P < 0.001) but not SGB (Pgenotype × dietary Lys = 0.008). It can be concluded that a dietary Lys content of 1.01% does not safeguard both growth performance and body protein accretion efficiency in both FGB and SGB. The suboptimal growth performance in FGB, but not SGB, is partially counteracted by a Lys-induced reduction in feed intake.

Supplementation with curcuminoids and tuna oil influenced skin yellowness, carcass composition, oxidation status, and meat fatty acids of slow-growing chickens.

The present study aimed to determine the effects of dietary curcuminoids combined with tuna oil on the growth performance, meat quality, thiobarbituric acid reactive substances (TBARS) values in the plasma and raw meat, and fatty acid profile of chicken meat. A total of 480 21-day-old mixed-sex slow-growing chickens was assigned to a completely randomized design model with 6 treatments and 4 replicates (pens) per treatment. The basal diet based on corn-soybean and 4% tuna oil was used as the negative control. The experimental diets comprised the basal diet supplemented with curcumin removed turmeric oleoresin to provide 20, 40, 60, or 80 mg/kg curcuminoids (CUR-20, CUR-40, CUR-60, and CUR-80, respectively) or dl-α-tocopheryl acetate at 200 ppm as the positive control (E-200). Finally, the vacuum-packed carcasses were stored frozen at -20°C for 3 mo to examine the effect of curcuminoids on changes in the TBARS values and fatty acid composition of the breast and thigh meat. Increasing the levels of curcuminoids tended to improve the feed conversion ratio (linear, P = 0.065) and significantly increased the proportion of breast fillet (linear, P = 0.037) and the yellowness of the skin of both the breast (linear, P = 0.016) and the thigh (linear, P = 0.023). The curcuminoids exhibited antioxidant properties, but their effect was not dose dependent. The CUR-20 and CUR-40 treatments increased the linoleic acid content but decreased the C22:6n-3 (DHA) content of the breast meat. The CUR-60 treatment inhibited oxidation (measured by TBARS) in the chicken meat similarly to dl-α-tocopheryl acetate but had no effect on the proportion of DHA in the breast or thigh meat. Auto-oxidation occurred in the breast meat but not in the thigh meat during the 3 mo of frozen storage. The present study showed that a suitable level of curcuminoids in the diet of slow-growing chickens was 60 mg/kg.