362. A Meta-analysis to Evaluate the Effects of a Phytogenic Feed Additive on Growth Performance of Grow-finish Pigs.

Abstract Phytogenic feed additives, also referred to as essential oils or plant-derived compounds, are increasingly used in swine production to support feed efficiency, gut health, and growth performance under commercial conditions. Digestarom Finish (DF; Animal Nutrition & Health, LLC, Pendergrass, GA) is a proprietary blend of essential oils and flavoring compounds designed to optimize nutrient utilization and feed conversion during the grow-finish phase. The objective of this study was to evaluate the effects of DF on growth performance of grow-finish pigs using a random-effects meta-analysis. A total of 10 independent trials conducted across six U.S. locations were included. Each study compared pigs fed a control diet with those fed the same diet supplemented with DF at 0.015% from approximately 25 kg to market weight. Study-level means, standard errors, and number of experimental units were collected to estimate effects on average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR). Data were analyzed using a DerSimonian and Laird random-effects model implemented via PROC MIXED in SAS, with the difference between treatment and control as the response variable and each observation weighted by the inverse of its within-study variance. Based on the random-effects model, supplementation with DF increased ADG by 0.015 kg/day (95% CI: 0.005 to 0.025; P = 0.016), increased ADFI by 0.031 kg/day (95% CI: 0.005 to 0.056; P = 0.046), and improved FCR by 0.042 (95% CI: −0.073 to − 0.011; P = 0.020). Heterogeneity was low to moderate across outcomes, indicating consistent performance responses across studies. Based on predictions from the random-effects model, supplementation with DF at 0.015% is expected to improve ADG by 0.6% to 3.0%, increase ADFI by 0.2% to 2.2%, and improve FCR by 0.7% to 1.7% in grow-finish pigs. Overall, these results indicate that DF supplementation provides consistent improvements in growth performance across diverse production environments.