Effects of probiotics in broilers growth performance: A meta-analysis of randomized controlled trials

BLAJMAN, J.E.; FRIZZO, L.S.; ZBRUN, M.V.; ASTESANA, D.M.; FUSARI, M.L.; SOTO, L.P.; ROSMINI, M.R.; SIGNORINI, M.L.

BRITISH POULTRY SCIENCE

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2014 vol. 55 p. 483 - 494

0007-1668

1.For many years, feed supplementation with antibiotics has been used to stabilize the gut flora, improve broilers? general parameters and prevent avian diseases. However, with the increasing concern about antibiotic resistance, the need of alternatives has been widely recognized, the supplementation of broiler diets with probiotics being one potential method. However, a consensus among authors about benefits derived from probiotics has not been reached. 2.The aim of this meta-analysis has been to establish the effects of probiotics on the growth performance of broilers (i.e., body weight gain (BWG) and feed efficiency (FE)). PubMed, Scopus and Scholar Google databases were searched from 1980 to 2012, regardless of the language used. The studies in the meta-analysis were selected on the basis of following inclusion criteria: randomized and controlled experiments using broilers without apparent disease and published in peer-reviewed journals studies. 3.Forty eight and forty six studies were included to assess probiotic effects on BWG and feed efficiency, respectively. Probiotics increased BWG compared to controls (SMD= 0.661, 95%CI 0.499?0.822) and enhance FE (SMD= −0.281, 95%CI −0.404 to −0.157) in the pooled standardized mean difference random effect model, considering the source of heterogeneity and publication biases. 4.The findings of this meta-analysis showed that application via water resulted in greater BGW and FE than administration through the feed. The result is not related to the use of mono-strain or multi-strain probiotics, although it may depend on the strain used. The number of broilers and the duration of the experiments had an impact on the outcomes. 5.However, there are evidences of publication bias and heterogeneity, so the results of this meta-analysis should be considered with caution. Additional studies should be conducted with the aim to identify the covariates which can explain the differences in the estimated effect sizes.