Broiler gastrointestinal tract responses to commercial diets containing different levels of a yeast fermentate

The objective was to evaluate a yeast culture product, ProBiotein^® (PB), on the gastrointestinal (GIT) morphology of Ross 308 males fed PB supplemented diets. Treatments consisted of a basal diet (Con), basal+0.2% PB (0.2PB), basal+0.5% PB (0.5PB), or basal+0.75% PB (0.75PB). Birds were randomly assigned to batteries on d 0 (n = 400, n = 10, k = 4, r = 2) and moved to floor pens following the same blocking design on d14. Birds were offered feed ad libitum with a starter, grower, and finisher phase, each 14 d. On d 14, 28, and 42, body weight, GIT weight, length, and pH were measured. Weight was reported as relative to body weight. Cross sections of the duodenum, jejunum, and ileum from d 14 were evaluated for villi height, crypt depth, and their ratio. Morphology data were analyzed using a linear mixed effect model (mixed effect = block) with Dunnett’s comparison with significance at P ≤ 0.05 (control = Con). Histology data were analyzed using a linear model (P ≤ 0.05). There were no differences found histologically. There were treatment × day interactions on gizzard, jejunal, ileal, and small intestine weights; and for duodenal, ileal, and small intestine lengths (P < 0.05). There was a treatment effect on gizzard pH and a treatment × day interaction on the cecal pH (P < 0.05). On d14, jejunal, ileal, and small intestine weights were greater in birds fed diets with 0.75PB compared with those fed Con (P < 0.05). Small intestine length was longer in birds fed 0.75PB compared with those fed Con (P < 0.05). On d28, gizzard pH was lower in birds fed diets with 0.75PB than in those fed Con (P < 0.05). On d42, duodenal lengths were lower in birds fed diets supplemented with 0.75PB compared with those fed Con (P < 0.05). On d42, birds fed diets with 0.75PB had longer ileums than those fed Con (P < 0.05). Cecal pH was higher in birds fed all treated diets on d14 but was then lower on d28 and 42 compared with those fed Con (P < 0.05). Overall, birds fed diets supplemented with PB had lower GIT weights, longer GIT segments, and lower GIT pH. Supplementing ProBiotein^® into a commercial poultry diet altered early intestinal development in chicks.

Key Words: yeast fermentate, poultry, gastrointestinal physiology, pH.

Published in the proceedings of the 10th Symposium on Gut Health in Production of Food Animals 2022, St. Louis, USA.