Effect of Dietary Mannan Oligosaccharide (Bio-Mos) on Live Performance of Broiler Chickens Given an Anticoccidial Vaccine (Paracox) Followed by a Mild Coccidial Challenge

Abstract

A pen trial with 720 Ross 308 male chicks evaluated effects of Paracox-5 vaccination at d 1, dietary mannan oligosaccharide (MOS; Bio-Mos at 2, 1, and 0.5 kg/tonne in starter, grower, and finisher, respectively), and d-15 Eimeria challenge on d-22 lesions and 1 to 42-d live performance. Available floor area in each of 24 floor pens was 2.1 m2, and 30 chicks were placed per pen initially. A 3-phase feeding program was used: starter (0 to 15 d), grower (16 to 22 d), and finisher (23 to 42 d). The 4 dietary and vaccine treatments were as follows: 1) without vaccination, dietary MOS, or coccidiosis challenge; 2) without vaccination and dietary MOS but with a 3-strain pathogenic Eimeria challenge; 3) with Paracox-5 vaccination and Eimeria challenge but no dietary MOS; and 4) with Paracox vaccination, dietary MOS, and Eimeria challenge. The pathogenic Eimeria sporulated oocysts mixture from the French National Institute for Agricultural Research (Paris, France), standardized and well-defined, was given via feed at d 15 (100,000 Eimeria acervulina, 10,000 Eimeria maxima, and 15,000 Eimeria tenella per bird). Coccidiosis lesion scores were recorded at 22 d of age (scored as 0, 1, 2, or 3 with increasing severity). Overall mean lesion scores (P < 0.001) were higher in challenged birds. Paracox-5 alone improved 15-d BW and 1 to 15- and 15 to 22-d average daily gain of Eimeria-challenged broilers (P < 0.05). Dietary MOS improved (P < 0.05) 15 to 42- and 22 to 42-d FCR of Paracox-5 vaccinated, Eimeria- challenged broilers. Mortality was 4.4 to 5.8% by treatment, with no significant differences. It was concluded that dietary MOS improved the feed conversion ratio of Paracox-5-vaccinated (d 1), challenged (d 15) broilers from 15 to 42 d of age.