Effect of a multi-strains yeast fractions product plus anticoccidial drug on performance, anticoccidial index, intestinal health, and bone mineralization of broiler chickens infected with Eimeria spp

The aim of this study was to investigate the combined effect of dietary supplementation of a multi-strains yeast fractions product (MSYF) and an anticoccidial on the performance and health of broiler chickens orally challenged with Eimeria spp. oocysts. A total of 192 male, 1-day-old, Ross-308 chicks were randomly allocated into 4 groups with 6 replicates of 8 chicks each, housed in separate cages. All groups were offered ad libitum water and the same basal diets of meal feed. The first group (negative control, NC) was unchallenged, whereas the second group (positive control, PC) was orally challenged with Eimeria spp. oocysts. The other two challenged groups had their diets further supplemented with either a coccidiostat (salinomycin 60 mg/kg feed, SAL) or a combination of a coccidiostat plus the examined MSYF (0.4 g/kg feed) (COMB). The three challenged groups were orally inoculated at 14 days of age with a specific amount of sporulated oocysts, containing 3.5 × 10 4 Eimeria acervulina , 7.0 × 10 3 Eimeria maxima , and 5.0 × 10 3 Eimeria tenella oocysts. Performance parameters were weekly recorded. On day 7 postinfection (p.i), coccidiosis lesions were scored, and intestinal samples were taken for histopathology evaluation as well as for oxidative status analysis. Also, femur and tibia bone mineralization along with their resistance to breaking was assessed. Counts of total aerobes, total anaerobes, coliforms, and lactobacilli were also enumerated in digesta samples from jejunum, ileum, and cecum by conventional microbiological techniques. Samples of intestinal digesta (duodenum, ileum, and ceca) were further subjected to coccidian enumeration by quantitative real-time PCR (qPCR). Fecal oocyst numbers were also determined consecutively on days 17 to 22 and on day 35. All data were subjected to a one-way analysis of variance (ANOVA) or Kruskal–Wallis test, depending on their normality and homoscedasticity. The combination of MSYF plus salinomycin (COMB) when compared to PC had improved ( P < 0.05) body weights of chicken up to day 26 of age, as well as higher ( P < 0.05) jejunum and cecum lactobacilli counts. Moreover, PC had lower ( P < 0.05) duodenum villus height compared to the other three groups and lower ( P < 0.05) jejunum villus height compared to NC and the MSYF plus coccidiostat group (COMB). The intestinal lesion scores were higher ( P < 0.05) in the PC group, whereas the anticoccidial drug (SAL) and the MSYF plus the COMB tended ( P < 0.10) to have less severe macroscopic lesions. The group COMB, when compared to PC, had lower ( P < 0.05) oocysts shedding during the acute phase of the challenge (days 17–22). Moreover, the qPCR analysis showed that group COMB had lower ( P < 0.05) DNA concentrations for every examined combination of Eimeria spp. and sampling site compared to the PC, but additionally, in some cases, lower ( P < 0.05) DNA concentrations compared to group SAL (duodenum E. maxima and E. tenella ; ileum E. acervulina , E. maxima , and E. tenella ; ceca E. maxima and E. tenella ). The combination of MSYF and anticoccidial (COMB) increased bone ash content in both femur and tibia and showed higher values of comprehensive strength. In conclusion, MSYF can be used in combination with salinomycin (COMB) to reduce the negative effects of an Eimeria challenge, as a consequence, improve growth performance in the challenged birds.