Effect of feeding protected sodium butyrate on production performance and intestinal morphology of broilers: A meta-analysis

The objective of this meta-analysis was to evaluate the effect of feeding protected sodium butyrate (PSB) on production performance and intestinal morphology of broiler chickens. A literature search was conducted to identify in vivo research studies on PSB supplementation in broiler chickens. The inclusion criteria were: a) the PSB type and the supplemental dose used; b) nature of the butyrate salt; c) experiments carried out on broilers; and d) exclusion of bacterial challenge trials. Seventeen experiments, including 64 observations and 12,204 broilers, were selected from published studies. Data extracted included the number of broilers in control and treatment groups and measures of variance of responses (SD or SEM). The response variables for production performance were BW, ADG, ADFI, feed conversion ratio (FCR) and European Production and Efficiency Factor (EPEF), and for intestinal morphology were villi height and crypts to villi height ratio. A random effect model was used to examine the raw mean difference and standardized mean difference between PSB supplementation and the control group. The analysis was conducted using the metafor package of R. Results were considered significant at P < 0.05. The PSB moderately improved the production performance parameters (BW, FI, ADG and FCR) and intestinal histomorphology responses of broilers with moderate (30 < I2 < 60%), to no evidence of heterogeneity (I2 = 0.0%), respectively. Final BW and ADG were increased by 40 g and 1.10g/day, respectively, or > 0.6 standard deviation units. The FCR was ameliorated in response to PSB supplementation by 0.015 units or > 0.3 standard deviation units. Meanwhile, the ADFI of chickens was not affected by PSB supply. The EPEF was higher for PSB compared to the control treatment. The histomorphology profile inspection of the intestine showed increased villi high by 9% or by > 0.4 standard deviation units, and villi:crypts ratio by 5% or by > 0.2 standard deviation units. The meta-analysis results demonstrated that PSB supplementation in broiler diets effectively enhanced production performance and promoted intestinal morphology.