Use of a long-term rumen simulation technique (Rusitec) to provide micro-organisms for in vitro digestibility assays
| Autor: | M. Lalenta, M. C. N. Jayasuriya, R. Hamilton, E. Owen |
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| Rok vydání: | 1991 |
| Předmět: | |
| Zdroj: | The Journal of Agricultural Science. 116:297-301 |
| ISSN: | 1469-5146 0021-8596 |
| Popis: | SUMMARYFour experiments involving the two-stage in vitro digestibility technique of Tilley & Terry (1963) were undertaken to investigate whether cow rumen liquor could be replaced with effluent or extract from feed residue containing micro-organisms derived from the long-term rumen simulation technique (Rusitec) of Czerkawski & Breckenridge (1977).In Expts 1 and 2, the dry matter digestibility (DMD) of hay was determined using either cow rumen liquor or Rusitec liquid effluent or extract from feed after 48 h of digestion in a Rusitec apparatus using various volumes of liquor and artificial saliva. Digestibilities determined with rumen liquor were c. 70% (c.v. 1·2%) while those determined with Rusitec effluent or extract were c. 62% (c.v. 1·8%). In treatments common to Expts 1 and 2, Rusitec effluent digestibilities were more repeatable than extract or rumen liquor digestibilities.In Expts 3 and 4, Rusitec effluent was compared with cow rumen liquor for determining DMD of seven forages with DMD ranging from 33 to 70%. For a given feed there was good agreement between experiments in DMD values determined with Rusitec effluent, and for ten paired values there was a high correlation (r2 = 0·976) between DMD determined by the two methods. DMD determined using rumen liquor (y) was accurately predicted by Rusitec liquid effluent digestibility (x) from the equation y = 2·663 + 1·06477.x; R.S.D. 2·433.The results show that Rusitec liquid effluent can be used instead of rumen liquor as a source of micro-organisms for the two-stage in vitro digestibility method. Routine use of Rusitec would obviate the need for using fistulated animals. |
| Databáze: | OpenAIRE |
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