Effects of age and supplemental xylanase in corn- and wheat-based diets on cecal volatile fatty acid concentrations of broilers

Authors: MCCAFFERTY, KLINT - Auburn University; BEDFORD, MIKE - Ab Vista; Kerr, Brian; DOZIER, WILLIAM - Auburn University

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2019
Publication Date: 5/7/2019
Citation: McCafferty, K.W., Bedford, M.R, Kerr, B.J., Dozier III, W.A. 2019. Effects of age and supplemental xylanase in corn- and wheat-based diets on cecal volatile fatty acid concentrations of broilers. Poultry Science. 98(10):4787-4800. https://doi.org/10.3382/ps/pez194.
DOI: https://doi.org/10.3382/ps/pez194

Interpretive Summary: Enzyme supplementation, such as xylanase, in broilers have been shown to improve nutrient utilization and bird growth, largely due to reducing digesta viscosity, nutrient encapsulation, and changes in microbial ecology. The current study was conducted to evaluate the effects of supplemental xylanase in corn- or wheat-based diets on cecal volatile fatty acid concentrations in broilers during weekly intervals from 14 to 42 d of age. Data from this experiment indicate that broiler cecal volatile fatty acid concentrations are influenced by both cereal grain source and age of bird, but the supplementation of the diet with xylanase had an inconsistent effect on broiler cecal volatile fatty acid concentrations. This information is important for nutritionists at universities, feed companies, and broiler production facilities for determining the value of a xylanase enzyme on improving the digestion of non-starch polysaccharides and subsequent bird growth, due to the age of the bird and the cereal grain composition of the diet.

Technical Abstract: An experiment was conducted to evaluate the effects of supplemental xylanase in corn- or wheat-based diets on cecal volatile fatty acid (VFA) concentrations of Ross × Ross 708 male broilers during weekly intervals from 14 to 42 d of age. Day-old chicks (1,500) were randomly distributed into 60 floor pens (25 chicks/pen; 0.078 m2/bird) and fed 1 of 4 dietary treatments (TRT) throughout the starter (1 to 14 d of age), grower (15 to 28 d of age), and finisher (29 to 42 d of age) phases with 15 replicates per TRT. Dietary TRT consisted of a 2 × 2 factorial arrangement with 2 diet types (corn- or wheat-based) and 2 xylanase inclusions (0 or 16,000 BXU/kg) as the main factors. At 14, 21, 28, 35, and 42 d of age, cecal contents were collected (4 birds/pen) for VFA analysis. Main effects of cereal grain source (P < 0.05) affected propionic, isobutyric, butyric, isovaleric, valeric, and isocaproic acid concentrations at 14, 21, 28, 35, and 42 d of age. Broilers fed corn-based diets had higher (P < 0.05) propionic, isobutyric, isovaleric, valeric, and isocaproic concentrations than those fed wheat-based diets from 14 to 42 d of age. However, broilers fed wheat-based diets had higher (P < 0.05) butyric acid concentrations at 28, 35, and 42 d of age compared with those fed corn-based diets. Individual and total VFA concentrations increased (P < 0.05) linearly from 14 to 42 d of age. Age and cereal grain interacted (P < 0.05) to affect propionic, isobutyric, butyric, isovaleric, and valeric acid concentrations. These results indicate that broiler cecal VFA concentrations are influenced by cereal grain source and age. In contrast, supplemental xylanase inconsistently influenced broiler cecal VFA concentrations. Therefore, future research evaluating factors affecting supplemental xylanase and cecal VFA production in broilers is warranted. Additionally, research investigating cereal grain source effects on cecal microflora development and fermentative patterns may be beneficial for optimizing cecal VFA production in broilers.