Effects of Mannan-Oligosaccharides and Live Yeast in Diets on the Carcass, Cut Yields, Meat Composition and Colour of Finishing Turkeys (Report‪)‬

INTRODUCTION The ban against using antibiotics as feed additives in poultry diets of many countries has led to an increase in research regarding alternative feed additives, including prebiotics such as mannan oligosaccharide (MOS) and probiotics like Saccharomyces cerevisiae (SC). MOS is derived from mannans on yeast cell surfaces. The benefits of MOS are based on specific properties, including modification of the intestinal micro-flora, reduction in turnover rate of the intestinal mucosa, and modulation of the immune system in the intestinal lumen. These properties have the potential to enhance growth rate, feed efficiency, and livability in poultry species (Parks et al., 2001). Probiotics, such as Saccharomyces cerevisiae, are defined as non-digestible ingredients, and they have several modes of action: beneficial changes in gut flora with reductions in the population of pathogenic bacteria, lactate production with subsequent changes in intestinal pH, production of antibiotic-type substances, production of enzymes, competition for adhesion receptors in the intestine, competition for nutrients, reduction of toxin release, and immuno-stimulation (Montes and Pugh, 1993; Leeson and Summers, 1997; Sohn et al., 2000; Han et al., 2007; Yin et al., 2008).