RESUMO
Pasture-flock-raised poultry are becoming an increasingly popular product, but only limited options are currently available for maintaining gut health. For these producers, prebiotics are an attractive option because they are generally recognized as safe (GRAS) and can be mixed into the feed and thus do not require adjustments to production protocols. However, if prebiotic treatments reduce production performance, they would not be useful to producers. Thus, the objective of this study was to measure performance of pasture-raised broilers fed 1 of 3 prebiotic treatments. For these trials, 2 breeds of birds were used: Naked Neck slow-growing breeds and Cornish White Rock cross fast-growing breeds. The experimental design was replicated for each breed. A total of 340 birds were split into 4 groups, each group fed one feed additive: 1) galactoligosaccharides (2% wt/wt), 2) fructooligosaccharides (1% wt/wt), 3) plum fibers (1% wt/wt), or 4) no additives. During the 8-wk rearing period, 10 birds from each group were collected and euthanized to take small intestine samples. Histological preparations were made from the small intestine tissue, and 4 measurements of villi height and crypt depth from each cross section were taken. Throughout the study, mortality was monitored and BW measurements were taken at 2-wk intervals. For the Cornish White Rock cross, the group receiving the feed supplemented with fructooligosaccharides had higher (P < 0.05) 8-wk BW than those fed Plum; control and birds fed galactoligosaccharides were intermediate. For the Naked Neck breed, the group receiving the plum fibers had the highest final BW. It appears that all 3 feed supplements offered some protective effect for alterations in villi length and crypt depth due to feed withdrawal, but only for the Naked Neck breed. The data indicate the 3 prebiotics utilized in this study could be used without risk of decreasing production performance, but only for Naked Neck breeds.