CECAL METABOLITES AND MICROBIAL-POPULATIONS IN CHICKENS CONSUMING DIETS CONTAINING A MINED HUMATE COMPOUND

The objectives of this study were to compare the short-chain fatty aci d (SCFA) concentrations, amino acid concentrations and key carbohydrat e-fermenting anaerobic bacterial populations in the caeca of chickens consuming either control diets or a mined humate compound (MH; Menefee Humate(TM)). Dietary MH at concentrations of 0, 5 or 10 g kg(-1) did not affect (P greater than or equal to 0.05) the caecal concentrations of SCFA and amino acids. Regardless of treatment, acetate was found t o be the predominant SCFA in the caecum followed by propionate (P < 0. 05). MH had no effect on the caecal concentrations of 17 amino acids c ompared with control birds but, when analysed across treatments, gluta mate was found to be the predominant free amino acid in the caecum, fo llowed by alanine (P < 0.05). MH did not significantly influence any o f the anaerobic microbial populations but Escherichia coli populations from birds receiving either 10 or 50 g kg(-1) MH were between 10 and 100 times greater than control birds (P < 0.05). It appears that MH do es not influence concentrations of fermentation acids or amino acids i n the caecum but may influence levels of individual microbial populati ons. (C) 1998 SCI.