Hostname: page-component-8448b6f56d-tj2md Total loading time: 0 Render date: 2024-04-24T18:36:41.372Z Has data issue: false hasContentIssue false

Comparison between reconstituted sheep faeces and rumen fluid inocula and between in vitro and in sacco digestibility methods as predictors of intake and in vivo digestibility

Published online by Cambridge University Press:  27 March 2009

I. V. Nsahlai
Affiliation:
International Livestock Centre for Africa (ILCA), PO Box 5689, Addis Ababa, Ethiopia
N. N. Umunna
Affiliation:
International Livestock Centre for Africa (ILCA), PO Box 5689, Addis Ababa, Ethiopia

Summary

This study (conducted in Debre Zeit, Ethiopia in 1993) examined (i) the effect of source of inoculum on in vitro dry matter (DM) digestibility (1VDMD) and gas production (GP) and (ii) the IVDMD, GP and in sacco degradability as predictors of in vivo DM digestibility (DMD) and intake. Six ruminally cannulated male sheep (used in the degradability studies and from which rumen fluid was harvested for the in vitro studies) and six intact sheep (from which faeces for reconstitution was obtained) were given teff straw ad libitum supplemented with 200 g/day of concentrate (1:1 mixture of noug (Guizotia abyssinica) cake and wheat middlings). In determining IVDMD on 26 feeds, pepsin-HC1 digestion was replaced with neutral detergent extraction. Microbial GP was measured on these feeds incubated with rumen fluid or reconstituted faeces inocula at various time periods. The degradability of each feed was determined by the nylon bag technique in three sheep. Eighty-eight intact male Ethiopian Menz type sheep (mean liveweight 256 (S.D. = 1·98) kg) were used in a randomized complete block experiment to determine intake and digestibility.

Gas production using faeces inoculum (GP-F) was strongly related to GP using rumen fluid inoculum (GP-R) particularly at 48 h (R2 = 0·85; P <0·001) of incubation. The IVDMD obtained with reconstituted sheep faeces inoculum (IVDMD-F) had a strong positive relationship (R2 = 0·88; P <0·0001) with IVDMD measured using rumen fluid (IVDMD-R). The IVDMD values obtained by centrifugation were positively related to those obtained by filtration for the rumen fluid (R2 = 0·61) and reconstituted faeces (R2 = 0·47) inocula.

The relationship between degradability and in vivo DMD was generally poor for roughages but improved with the length of incubation for forage legumes, being strongest at 24 h (R2 = 0·54). The in vivo DMD had the strongest relationship with GP-R at 24 h of incubation for roughages (R2 = 0·64) and legumes (R2 = 0·84). Dry matter degradability was poorly related to DM intake for roughages (R2 <0·10), while these were closely related for legumes particularly at 6 h of incubation (R2 = 0·55). The relationship between GP-R and intake was strongest at 12 h of incubation for roughages (R2 = 0·41) but was generally weak for legumes. The IVDMD accounted for a very low proportion of the variation in intake of roughages and legume forages. The gas production method was the best among the methods tested in predicting voluntary roughage intake, but not the intake of legumes. The nylon bag technique gave the best predictors (solubility, rate constant ‘c’ and Lag phase) of legume intake (R2 = 0·98).

The discussion suggests explanations for why the nylon bag technique predicted performance from forage legumes better than from roughages, why the technique was much better as a predictor of intake than of in vivo DMD, and why the gas production technique predicted in vivo DMD and not the intake of legumes. Reconstituted faeces inoculum may replace rumen fluid inoculum in in vitro procedures. The IVDMD method is a less accurate predictor of in vivo DMD than GP and rumen degradability constants. Both feed factors and practices inherent in the methodologies may modify the predictiveness of indirect digestibility methods.

Type
Animals
Copyright
Copyright © Cambridge University Press 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Association Of Official Analytical Chemists (1980). Official Methods of Analysis, 13th Edn. Washington, DC: AOAC.Google Scholar
Barry, T. N. (1989). Condensed tannins: their role in ruminant protein and carbohydrate digestion and possible effects upon the rumen ecosystem. In The Roles of Protozoa ami Fungi in Ruminant Digestion (Eds Nolan, J. V., Leng, R. A. & Demeyer, D. I.), pp. 153169. Armidale, Australia: Penambul Books.Google Scholar
Blümmel, M. & ØRskov, E. R.. (1993). Comparison of in vitro gas production and nylon bag degradability of roughages in predicting feed intake in cattle. Animal Feed Science and Technology 40, 109119.CrossRefGoogle Scholar
Bonsi, M. L. K., Osuji, P. O. & Tuah, A. K. (1995). Effect of supplementing teff straw with different levels of leucaena or sesbania leaves on the degradabilities of teff straw, sesbania, leucaena, tagasaste and vernonia and on certain rumen and blood metabolites in Ethiopian Menz sheep. Animal Feed Science and Technology 52, 101129.CrossRefGoogle Scholar
Carro, M. D., Lopez, S., Gonzalez, J. S. & Ovejero, F. J. (1994). Comparison of laboratory methods for predicting digestibility of hay in sheep. Small Ruminant Research 14, 917.CrossRefGoogle Scholar
El Shaer, H. M., Omed, H. M., Chamberlain, A. G. & Axford, R. F. E. (1987). Use of faecal organisms from sheep in the in vitro determination of digestibility. Journal of Agricultural Science, Cambridge 109, 257259.CrossRefGoogle Scholar
Goering, H. K. & Van Soest, P. J. (1970). Forage Fiber Analysis, USDA Agriculture Research Service No. 379. Washington, DC: ARS/USDA.Google Scholar
Jouany, J. P. (1994). Methods of manipulating the microbial metabolism in the rumen. Annales de Zootechnie 43, 4962.CrossRefGoogle Scholar
Khazaal, K., Dentinho, M. T., Ribeiro, J. M. & Ørskov, E. R. (1993). A comparison of gas production during incubation with rumen contents in vitro and nylon bag degradability as predictors of the apparent digestibility in vivo and the voluntary intake of hays. Animal Production 57, 105112.Google Scholar
Kibon, A. & Ørskov, E. R. (1993). The use of degradation characteristics of browse plants to predict intake and digestibility by goats. Animal Protection 57, 247251.Google Scholar
Li, X., Kellaway, R. C., Ison, R. L. & Annison, G. (1992). Chemical composition and nutritive value of mature annual legumes for sheep. Animal Feed Science and Technology 37, 221231.CrossRefGoogle Scholar
Mehrez, A. Z. & Ørskov, E. R. (1977). A study of the artificial fibre bag technique for determining the digestibility of feeds in the rumen. Journal of Agricultural Science, Cambridge 88, 645650.CrossRefGoogle Scholar
Menke, K. H., Raab, L., Salewski, A., Steingass, H., Fritz, D. & Schneider, W. (1979). The estimation of the digestibility and metabolizable energy content of ruminant feedingstuffs from the gas production when they are incubated with rumen liquor in vitro. Journal of Agricultural Science, Cambridge 93, 217222.CrossRefGoogle Scholar
Minson, D. J. (1982). Effect of chemical composition on feed digestibility and metabolizable energy. Nutrition Abstracts and Reviews, Series B 52, 591615.Google Scholar
Nsahlai, I. V. (1991). The effect of quantity and quality of dietary protein upon straw utilization by steers. PhD thesis, University of Reading.Google Scholar
Ørskov, E. R. & McDonald, I. (1979). The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage. Journal of Agricultural Science, Cambridge 92, 499503.CrossRefGoogle Scholar
Ørskov, E. R., Reid, G. W. & Kay, M. (1988). Prediction of intake by cattle from degradation characteristics of roughages. Animal Production 46, 2934.Google Scholar
Schneider, B. H. & Flatt, W. P. (1975). The Evaluation of Feeds through Digestibility Experiments. Athens, GA: University of Georgia Press.Google Scholar
Siaw, D. E. K. A., Osuji, P. O. & Nsahlai, I. V. (1993). Evaluation of multipurpose tree germplasm: the use of gas production and rumen degradation characteristics. Journal of Agricultural Science, Cambridge 120, 319330.CrossRefGoogle Scholar
Statistical Analysis Systems Institute (1987). Procedures Guide for Personal Computers, Version 6 Edition. Cary, NC: SAS Institute.Google Scholar
Tilley, J. M. A. & Terry, R. A. (1963). A two-stage technique for the in vitro digestion of forage crops. Journal of the British Grassland Society 18, 104111.CrossRefGoogle Scholar
Van Soest, P. J. (1982). Nutritional Ecology of the Ruminant: ruminant metabolism, nutritional strategies, the cellulolytic fermentation and the chemistry of forages and plant fibers. Ithaca, NY: Cornell University Press.Google Scholar