Coccidiosis continues to be a major challenge in poultry production, especially in systems no longer using antibiotics. Many producers implement coccidiosis control programs utilizing combinations of coccidiosis vaccines, coccidiostats, and feed additives. Depending on the modes of action of the feed additive, combining or replacing different strategies may be advantageous. Two feed additives were evaluated: (1) a phytogenic (PHYT) as a replacement of a chemical coccidiostat, and (2) a synbiotic (SYN) as an enhancement of a coccidiosis vaccine. Both studies utilized 800 day-old Cobb 500 chicks randomly allocated to 1 of 4 treatment groups (8 replicate pens per treatment with 25 birds per pen). The first study consisted of a non-challenged control (NCC), a challenged control (CC), CC supplemented with zoalene (ZOA; 125 ppm), or CC supplemented with a PHYT (PHYT; 125 g/MT). The second study consisted of NCC, CC, CC administered a coccidiosis vaccine at placement (VAC), or VAC supplemented with SYN (SYN; 500 g/MT). In each study, birds were raised on used litter and on d 19, 20, and 21, 1 × 108 cfu/bird of Clostridium perfringens was administered via the feed. Data from each study were analyzed independently using GLIMMIX procedure of SAS with significance reported at P < 0.05. The CC resulted in a 9-point (P < 0.05) and 6-point (P < 0.05) increase in FCR compared with the NCC for study 1 and study 2, respectively. In study 1, final body weight and FCR were significantly improved (P < 0.05) in the ZOA- and PHYT-supplemented groups compared with the CC, but were similar to each other as well as the NCC. In study 2, supplementation with SYN was able to improve FCR by 7 points compared with VAC group (P < 0.05) and was similar to the NCC. Body weight was numerically (P > 0.05) improved in SYN birds compared with VAC birds. Additionally, oocyst shedding was increased (P < 0.05) in VAC and SYN on d 14 and d 21, suggesting normal cycling of the vaccine oocysts had occurred. Incorporating either of these feed additives was advantageous in the context of each coccidiosis control program.
Key Words: coccidiosis, feed additive, broiler.
Presented at the 9th Symposium on Gut Health in Production of Food Animals, St. Louis, USA, 2021. For information on the next edition, click here.