Exploration of fecal microbial transfer and the competitive exclusion concept in broilers as a possible alternative to antibiotic growth promoters
Authors:   , Morris Colwayne Dennison 
Published: May 2022

Four studies were conducted to explore the effects of early life Fecal Microbiota Transfer (FMT) from healthy feed efficient finished broilers into day-old broiler chicks on growth performance indices, changes and or differences in microbiome, and impact on immunocompetences from hatch to 21 days and hatch to 42 days of age, raised on used litter and wire mesh battery cages. Results in the studies here in showed that FMT treatment had a major effect (P<0.05) on growth performance for the first 7 days but subsequently exhibited recovery from 14 through 21 days. Thus, inoculating day-oldbirds with FMT (excreta content in saline) of healthy adult birds would not affect (P>0.05) growth performance of broilers from 0- 21 or 0- to 42 day old. Early life FMT treatment into day-of-hatch broiler chicks did not show differences in intestinal microbial population from 0- to 21 d old. Additionally, FMT did not impact overall percent livability at d 42, though there was a possible difference (P=0.059) in percent livability from 0-42 d among control (84.5 percent) and the three graded levels of FMT treated birds (0.5, 0.25 and 0.2 cc) being 93.5 percent, 84 percent, and 93 percent respectively. The ratio of IL17 to IL10 RNA expression was significantly higher in FMT using excreta from feed efficient finished broilers and may impact the promotion of innate immunity. Thus, early life FMT from healthy feed efficient finished broilers may promote livability by stimulating innate and adaptive immunity of recipient chicks. The concept of FMT was pioneered by Nurmi and Rantala (1973) in broilers to control Salmonella and other pathogen colonization through competitive exclusion hence, the administration of fecal microbiota from healthy adult chickens to newly hatched chickens to colonize their GI tract (Rantala & Nurmi, 1973; Pivnick and Nurmi, 1982; Mead et al, 1989). The FMT stock was prepared from fresh excreta droppings and cecal samples were collected without the uric acid portion from healthy feed efficient 6 weeks old Ross 308 broilers, pooled in 0.9 percent saline solution. The FMT culture was administered to day-of-hatch broilers via oral gavage at 0.25 cc per chick before placement in battery pens. Control group of birds were administered (0.25 cc) 0.9 percent saline solution. Feed was withheld for 2 hrs. after placing the last group of chicks. The rise in public health concerns surrounding antimicrobial resistance triggered the move to ban the use of Antimicrobials (AGPs) in poultry feed. Recently, increased efforts are being placed into finding suitable alternatives to AGPs and optimizing the gut microbiota of chickens using dietary interventions since its complex microbial ecosystem produces a wide range of metabolites that have been associated with improved or decreased productivity. Though FMT was initially used for enteropathogenic control, some filed studies showed that the treatment may enhance growth performance and feed conversion and decrease mortality and morbidity of poultry. Through molecular investigation of the chicken GIT microbiota the industry now has a new level of understanding, surveys of phylogenetic markers such as PCR and 16S rRNA gene sequencing have allowed researchers to overcome some of these challenges particularly associated with culture-based surveys. Although there is increasing evidence for a connection between feed efficiency and gut microbiota in broilers, the relationship is still not yet fully understood. Future research on the impact of FMT in broilers may explore the benefits of the FMT method and its competitive exclusion mechanism to enumerate its potential contributions to immunocompetence in broilers.