Phytogenic compounds, probiotics and organic acids are used in broiler feeds as an option to AGPs due to their ability to emulate properties of antibiotics. This study’s goal was to compare a field AGP (virginiamycin 100 g/MT) program (T1) with two antibiotic free programs: Lactococcusbased probiotic+yeast MOS+a blend of Italian Chestnut-C/Argentine Quebracho-Q bioactive extracts (T2), or, a blend of C+Q alone (T3). A 42-day floor pen trial was conducted with a total of 1,575 of Arbor Acres® Max male broilers which were randomly distributed to 3 treatments (45 total pens); each treatment (525 birds) was fed to 15 pens of 35 birds/pen. Body weight, feed consumption and conversion were determined at 21 and 42 days of age. Livability and overall health were routinely measured and recorded. Intestinal health (lesion score) was evaluated at day 21 and 42. Caecal and litter samples were taken at these times for microbiota, bacterial, and moisture determination, and, measurement of the spread of environmental antimicrobial resistance. Body weight (T1; 1.052; T2: 1.072; T3: 1.077, kg, respectively) and feed conversion were significantly improved (P < 0.05) on day 21. No significant differences among treatments on day 42 were observed for body weight-kg (T1: 2.978; T2: 2.975; T3: 3.003) and feed conversion-Feed/Weight (T1: 1.728; T2: 1.714; T3: 1.715). Microbiota analysis showed a differential effect among treatments, i.e., alpha diversity, number of species and specific groups of beneficial bacteria were improved by the non-AGP treatments. Food pad and intestinal health was generally good and similar among treatments. Both non-AGP treatments showed a tendency to reduce antibiotic resistance in representative bacteria from the intestine and litter.
Key Words: polyphenols, poultry, commercial farms