The Effects of Dietary Whole Rice Hull as Insoluble Fiber on the Flock Uniformity of Pullets and on the Egg Performance and Intestinal Mucosa of Laying Hens

Abstract

Our two experiments were intended to investigate the effects of dietary Whole Rice Hull (WRH) as insoluble fiber on the flock uniformity of pullets and the performance, egg quality and intestinal mucosa structure of laying hens. In experiment 1, a total of 1,500 chicks (4 weeks old) with the same uniform weight were randomly separated into three treatments of 500 birds each and fed diets containing 0 (control), 3 and 6% WRH. With increasing dietary WRH levels, body weight and feed intake were higher (p<0.05); the 3 and 6% WRH groups were higher than the control group. The Feed Conversion Ratio (FCR) was lowest (p<0.05) in the 3% WRH-fed birds. In addition, the percentage of flock uniformity tended to increase in both dietary WRH groups. In the experiment 2, a total of 48 of the highest-producing hens (32 weeks old) were divided into three groups of 16 birds each and fed diets containing 0, 3 and 6% WRH. Hen-day egg production was 2.56% higher in the 6% WRH group and 1.48% higher in the 3% WRH group than in the control, without any distinctly adverse effects on egg quality. Morphologically, no significant differences were observed in the light microscopic parameters, with the exception that the muscularis externa width showed a higher value in the duodenum of the 6% WRH group and in the ileum of both dietary WRH groups. Epithelial cellular phenomena of the jejunum and ileum were similar among treatments, except cell clusters with numerous protuberated epithelia were found in the 6% WRH group. In conclusion, the current data indicate that WRH can be used as a source of insoluble fiber in diets up to 6% to enhance growth and uniformity of pullet chicks and to improve egg production of laying hens without any harmful impact on egg quality or on the intestinal mucosa structure.