Effects of supplementing palm kernel meal on growing-finishing pig’s diet: Meta-analysis

Abstract

Numerous studies have been conducted to determine the effects of feeding diets containing variable inclusion rates of palm kernel meal (PKM) on growth performance of growing-finishing pigs but responses among these studies are inconsistent. Therefore, a systematic review and a meta-analysis was conducted to quantitatively summarize the impact of feeding PKM diets on growth performance including average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed (G : F) ratio. Mean differences of ADG, ADFI, and G : F ratio were calculated using data from 5 studies with 42 observations. The impact of feeding PKM was calculated using the Cohen’s d (CD) to measure differences among control and experimental means, including the effect of pooled standard deviation of treatments. The heterogeneity (I2-statistic, %) across studies was calculated based on Cochran’s Q-statistic method. Inclusion of PKM in the growing- finishing pig diets significantly impact on the effect size of all growth parameters including ADG, ADFI, and G : F ratio (p < 0.01, respectively), but no detrimental trend was observed by increasing levels of PKM on growth performance. It presumably due to the existence of consi- derable heterogeneity (I2 > 95%) and lack of observations in the dataset, which lead to mask the true impact of PKM in the diet on the performance of growing-finishing pigs. Regardless of these overall responses, PKM continues to be an important and economically justifiable alternative energy and protein source which can be used effectively in swine diets in the global feed industry.