Changes in in vitro ruminal and post‐ruminal degradation of tropical tannin‐rich legumes due to varying levels of polyethylene glycol

• Published in: Journal of animal physiology and animal nutrition 2017-08, Vol.101 (4), p.641-648
• Main Authors: Knowles, M. M., Pabón, M. L., Hess, H. D., Carulla, J. E.
• Format: Article
• Language: English
• Subjects: Abomasum; Ammonia; Animals; Biodegradation; Buffers; Calliandra calothyrsus; Cattle; Degradation; digestibility; Dry matter; Fabaceae - chemistry; Feeds; Flemingia macrophylla; Foliage; In vitro methods and tests; Leaves; Legumes; Polyethylene glycol; Polyethylene Glycols - chemistry; Polyethylenes; polyphenols; Proteins; Ratios; Rumen - chemistry; Species Specificity; Tannins; Tannins - chemistry; Tubes
• ISSN: 0931-2439; 1439-0396
• DOI: 10.1111/jpn.12610

Summary We evaluated the effects of tannins from Flemingia macrophylla (CIAT 17403) and Calliandra calothyrsus (San Ramón CIAT 22310 and Patulul CIAT 22316) on in vitro ruminal and post‐ruminal dry matter and apparent protein degradation. For each tannin source (legumes), different dosages of polyethylene glycol (PEG) (8000 Da) in McDougall buffer were added to achieve ratios of 0:3, 1:3, 2:3 and 3:3 PEG:condensed tannin (CT). Ruminal fluid mixed with McDougall buffer (1:4) was added to tubes containing only legume foliage (control) or PEG‐treated legume foliage. For both Calliandra varieties, a higher ruminal dry matter degradation was observed at a PEG:CT ratio of 3:3. For F. macrophylla, no differences were found between 2:3 and 3:3 ratios (p > 0.05), indicating that a PEG:CT ratio of 2:3 might be enough to bind tannins. Increasing PEG:CT ratios increased apparent ruminal degraded protein and ammonia concentration (p