Effects of Dietary Antibiotics, Actigen® Yeast Cell Wall Derivative, or Both on Broiler Chicken Live Performance in a Fifty-Two Day Pen Trial on Built-up Litter

A 52-day pen trial on 10.2 cm built-up litter topped with pine shavings used a randomized complete block design (Tukey’s HSD p≤0.05). A total of 2,160 Cobb male chicks were randomly assigned to 48 pens (12 blocks) at 45 chicks/pen providing 0.0771 m2 per chick. Four phase feeds were used (0-17, 17-31, 31-42, and 42-52 days). Salinomycin (66.14 mg/kg) and 3-Nitro® 20 (50.0 mg/kg) were added from 0-31 days. Dietary treatments were: 1) negative control (nCON); 2) BMD® at 55.12 mg/kg 0-31 days, Stafac® at 22.05 mg/kg 31-52 days (AGP); 3) Actigen® (ACT) at 400 mg/kg; and 4) BMD® at 55.12 mg/kg 0-31 days, Stafac® at 22.05 mg/kg 31-52 days plus Actigen® (ACT) at 400 mg/kg (AGP＋ACT). From 0-17 days, feed conversion ratio (FCR; p＝0.026) and mortality-adjusted FCR (MAFCR; p＝0.027) were lower for AGP and AGP＋ACT than nCON, with ACT intermediate and statistically separate from other groups. At 31 days, body weight (BW; p＝0.043) was greater for AGP＋ACT than nCON, with AGP and ACT intermediate. From 0-31 days, FCR (p