title: Short communication: The effect of an exogenous enzyme with amylolytic activity on gas production and in vitro rumen starch degradability of small and large particles of corn or barley meals.
abstract: The objective of this study was to evaluate the effect of exogenous amylase supplementation on gas production and on in vitro rumen starch degradability (IVSD) of different sized particles of corn and barley meals (Cm and Bm, respectively). An aqueous liquid amylase formulation from Bacillus licheniformis was tested at 3 enzyme doses (EnzD; 0, 300 and 1,500 kilo novo units/kg of dry matter) on small (<750 µm) and large (≥750 µm) particle size (PS) of Cm and Bm. Data were analyzed according to a randomized complete block design with a factorial arrangement of treatments; the main tested effects were PS, EnzD, and their interaction. Fermentation run entered in the model as random effect. The mixed rumen fluid was collected from 2 rumen-fistulated Holstein dry dairy cows fed at maintenance (forage:concentrate ratio of 80:20; 12% crude protein; 55% amylase-treated neutral detergent fiber). Small particles of both Cm and Bm had a greater rate of fermentation and shorter lag time than large particles. The rate of starch degradation was greater for small than for large particles of Bm, being 0.187 and 0.125 1/h, respectively. Conversely, the rate of starch degradation of Cm averaged 0.063 1/h and was similar among treatments. Enzyme supplementation tended to reduce lag time and to increase rate of fermentation for both PS of Cm and Bm, with a more pronounced effect for small PS. A limited EnzD effect was measured for IVSD data and rate of starch degradation; PS influenced fermentation parameters and the magnitude of starch degradation more than EnzD. Supplementation with exogenous amylase influenced the rumen fermentation pattern of small and large PS of Cm and Bm, even if the effect of the enzyme supplementation differed according to the PS of cereal meals.
authors.affiliation: Feed & Food Science and Nutrition Institute, Faculty of Agriculture, Università Cattolica del Sacro Cuore, 29100 Piacenza, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Gallo
authors.affiliation: Feed & Food Science and Nutrition Institute, Faculty of Agriculture, Università Cattolica del Sacro Cuore, 29100 Piacenza, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Giuberti
authors.affiliation: DSM Nutritional Products, 1 Bd d'Alsace, Village-Neuf. BP170, France.
authors.forename: S
authors.initials: S
authors.lastname: Duval
authors.affiliation: Feed & Food Science and Nutrition Institute, Faculty of Agriculture, Università Cattolica del Sacro Cuore, 29100 Piacenza, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Moschini
authors.affiliation: Feed & Food Science and Nutrition Institute, Faculty of Agriculture, Università Cattolica del Sacro Cuore, 29100 Piacenza, Italy. Electronic address: francesco.masoero@unicatt.it.
authors.forename: F
authors.initials: F
authors.lastname: Masoero
mesh_terms: D000821:Animal Feed; D000818:Animals; D002417:Cattle; D004063:Digestion / Q000187:drug effects; D005260:Female; D005285:Fermentation; D001467:Hordeum / Q000378:metabolism; D007774:Lactation / Q000187:drug effects; D008892:Milk / Q000378:metabolism; D012417:Rumen / Q000378:metabolism*; D013213:Starch / Q000378:metabolism; D003313:Zea mays / Q000378:metabolism*
chemical_list: D013213:Starch
keywords: exogenous amylase; gas production; particle size; starch degradation