Fructooligosaccharide Supplementation Boosts Growth Performance, Antioxidant Status, and Cecal Microbiota Differently in Two Rabbit Breeds

SIMPLE SUMMARY: Rapidly rising incomes are dependent on animal protein production and the worldwide demand for livestock. It is expected that moving towards more intensive production systems to sustain this increased demand will depend on growth promoters. Some growth promoters, such as prebiotics, might be considered alternative non-antibiotic feed supplementation as they enhance performance without any side effects on the consumer’s health. The present study inspected the influence of supplementation of β-fructan(®) (a commercial fructooligosaccharide; FOS) in the drinking water of growing rabbits on growth performance, carcass traits, hematological and biochemical indices, antioxidant status, and cecal microbiota of the NZW- and APRI-line rabbits (Animal Production Research Institute Line). FOS supplementation in rabbits enhanced growth carcass characteristics, significantly improving hematological parameters and antioxidant status, and minimized pathogenic Escherichia coli bacteria (from 3.45 in control groups to 2.89 and 2.24 (Log10 CFU g(−1)) in 0.5 mL and 1 mL FOS-treated rabbits, respectively. ABSTRACT: The present study examined the effects of fructooligosaccharide (FOS) supplementation in drinking water on the growth performance, carcass characteristics, hematological and biochemical parameters, antioxidant status, and cecal microbiota of New Zealand White (NZW) and APRI rabbits. A total of 180 male NZW and APRI rabbits (aged five weeks; average live body weight 700 ± 39 g) were divided into six groups (30 rabbits/group; 5 replicates/group) in a two × three factorial arrangement. Rabbits of each breed were randomly assigned to one of three treatments of FOS (control; 0.00, FOS-0.5, and FOS-1.0). Results showed that rabbits’ final body weight, FBWG, and carcass traits were considerably enhanced compared to those in the control group. The interaction effect of the supplement with the rabbit breed increased the growth, carcass traits, and hematobiochemical and antioxidant parameters with increasing FOS levels. In the cecum of both rabbit breeds, the total bacterial count and Escherichia coli population were considerably low, with a substantial increase in the number of Lactobacilli supplemented by FOS. In conclusion, FOS supplementation enhanced growth and carcass traits by improving the hematobiochemical parameters and antioxidant status and reducing cecal pathogenic bacteria in both breeds.