Effects of dietary bamboo vinegar supplementation on performance, eggshell quality, ileal microflora composition, and intestinal villus morphology of laying hens in the late phase of production.

This study investigated the effects of bamboo vinegar (BV) supplementation on performance, eggshell quality, ileal microflora, and villus morphology in aged laying hens. A total of 320 hens (70 weeks old) were divided into 4 dietary treatments with 10 replicates of 8 hens each. They were fed a basal diet supplemented with BV at 0%, 0.2%, 0.4%, or 0.8% level until 86 weeks of age. The level of BV in the diet had no effect on egg performance, feed intake, or feed efficiency (p > 0.10). Damaged egg rate decreased in the hens fed the 0.4% and 0.8% BV diets during 79-86 weeks of age (p < 0.05). Eggshell thickness and eggshell strength were higher in the hens fed the 0.4% and 0.8% BV diets at weeks 82 and 86 compared to the controls. In the ileal content, population of Escherichia coli and Salmonella spp. decreased with 0.4% and 0.8% BV (p < 0.05). Villus height and areas of duodenum were higher in the hens fed the 0.4% and 0.8% BV diets (p < 0.05). The results indicate that a level of 0.4% BV in a layer's diet is sufficient for reducing pathogenic bacteria, stimulating intestinal functions and improving eggshell quality of laying hens in the late phase of production.