J. Anim Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Morgavi, D. P.
Right arrow Articles by Yang, W. Z.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Morgavi, D. P.
Right arrow Articles by Yang, W. Z.

Journal of Animal Science, Vol 79, Issue 6 1621-1630, Copyright © 2001 by American Society of Animal Science

JOURNAL ARTICLE

Resistance of feed enzymes to proteolytic inactivation by rumen microorganisms and gastrointestinal proteases

D. P. Morgavi, K. A. Beauchemin, V. L. Nsereko, L. M. Rode, T. A. McAllister, A. D. Iwaasa, Y. Wang and W. Z. Yang
Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, AB, Canada, T1J 4B1. morgavid@em.agr.ca

Potential feed enzyme additives for ruminants were tested in vitro for their stability to ruminal microbial and gastrointestinal proteolysis. Four commercial preparations from Trichoderma longibrachiatum (A, B, C, and D) and one from an undisclosed source (E) were incubated up to 6 h with ruminal fluid taken from four lactating dairy cows before or 2 h after feeding. The stability of preparation B was also tested in the presence of pepsin at pH 3 and pancreatin at pH 7. Cellulase (EC 3.2.1.4), cellulose 1,4-beta-cellobiosidase (EC 3.2.1.91), beta-glucanase (EC 3.2.1.6), xylanase (EC 3.2.1.8), beta-glucosidase (EC 3.2.1.21), and beta-xylosidase (EC 3.2.1.37) activities were monitored throughout the incubations. Polysaccharidase activities of all enzyme preparations were remarkably stable in ruminal fluid taken after feeding. Ruminal fluid obtained before feeding inactivated the polysaccharidases in preparations B and D to a greater extent than ruminal fluid obtained after feeding. Cellulase and cellulose 1,4-beta-cellobiosidase activities were the least stable, declining (P < 0.05) by 35 and 60% for preparations B and D, respectively. Xylanase activity of preparation D decreased (P < 0.05) by up to 30% after 6 h of incubation, whereas beta-glucanase activity was not affected. The ability to degrade exogenous enzymes also differed among cows (P < 0.05). Pepsin and acid (pH 3.0) did not affect polysaccharidases in preparation B but decreased glycosidase activities by 10 to 15% (P < 0.05) after 1 h of incubation. Pancreatin, at the maximum concentration used, inactivated cellulase, cellulose 1,4-beta-cellobiosidase, and xylanase activities at a rate of 0.55, 1, and 0.45%/min, respectively. beta-Glucosidase and beta-xylosidase activities decreased by 1 and 0.75%/min, respectively. Partial proteolysis of cellulase, cellulose 1,4-beta-cellobiosidase, and xylanase by pancreatin produced a transient increase in activity. This twofold increase for cellulase and fourfold increase for cellulose 1,4-beta-cellobiosidase was directly proportional to pancreatin concentration. These results suggest that the enzyme feed additives tested were stable in the rumen of animals after feeding. Exogenous enzymes are likely to be more susceptible to the host gastrointestinal proteases in the abomasum and intestines than to ruminal proteases. However, exogenous polysaccharidases may survive for a considerable period of time in the small intestine and they probably maintain activity against target substrates in this environment.


This article has been cited by other articles:


Home page
 J ANIM SCIHome page
L. A. Giraldo, M. L. Tejido, M. J. Ranilla, S. Ramos, and M. D. Carro
Influence of direct-fed fibrolytic enzymes on diet digestibility and ruminal activity in sheep fed a grass hay-based diet
J Anim Sci, July 1, 2008; 86(7): 1617 - 1623.
[Abstract] [Full Text] [PDF]

Home page
 J DAIRY SCIHome page
E. A. Elwakeel, E. C. Titgemeyer, B. J. Johnson, C. K. Armendariz, and J. E. Shirley
Fibrolytic Enzymes to Increase the Nutritive Value of Dairy Feedstuffs
J Dairy Sci, November 1, 2007; 90(11): 5226 - 5236.
[Abstract] [Full Text] [PDF]

Home page
 J ANIM SCIHome page
Y. Wang, B. M. Spratling, D. R. ZoBell, R. D. Wiedmeier, and T. A. McAllister
Effect of alkali pretreatment of wheat straw on the efficacy of exogenous fibrolytic enzymes
J Anim Sci, January 1, 2004; 82(1): 198 - 208.
[Abstract] [Full Text] [PDF]

Home page
 J ANIM SCIHome page
D. Colombatto, F. L. Mould, M. K. Bhat, D. P. Morgavi, K. A. Beauchemin, and E. Owen
Influence of fibrolytic enzymes on the hydrolysis and fermentation of pure cellulose and xylan by mixed ruminal microorganisms in vitro
J Anim Sci, April 1, 2003; 81(4): 1040 - 1050.
[Abstract] [Full Text] [PDF]

Home page
 J ANIM SCIHome page
K. A. Beauchemin, D. Colombatto, D. P. Morgavi, and W. Z. Yang
Use of Exogenous Fibrolytic Enzymes to Improve Feed Utilization by Ruminants
J Anim Sci, February 1, 2003; 81(14_suppl_2): E37 - 47.
[Abstract] [Full Text] [PDF]

Home page
 J DAIRY SCIHome page
G. R. Bowman, K. A. Beauchemin, and J. A. Shelford
The Proportion of the Diet to which Fibrolytic Enzymes are Added Affects Nutrient Digestion by Lactating Dairy Cows
J Dairy Sci, December 1, 2002; 85(12): 3420 - 3429.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2001 by the American Society of Animal Science.