Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-26T16:52:01.476Z Has data issue: false hasContentIssue false

In situ incubation sequence and its effect on degradation of food components when measured in the caecum of ponies

Published online by Cambridge University Press:  18 August 2016

J. J. Hyslop
Affiliation:
Department of Veterinary Clinical Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roślin, Midlothian EH25 9RG
G. J. Stefansdottir
Affiliation:
Department of Veterinary Clinical Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roślin, Midlothian EH25 9RG
B. M. L. McLean
Affiliation:
Department of Veterinary Clinical Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roślin, Midlothian EH25 9RG
A. C. Longland
Affiliation:
Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth SY23 3EB
D. Cuddeford
Affiliation:
Department of Veterinary Clinical Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roślin, Midlothian EH25 9RG
Get access

Abstract

Three experiments were conducted to investigate the effect of bag incubation sequence on the degradation of food components in situ in the caecum of mature, caecally fistulated Welsh-cross pony geldings (mean live weight 278 kg) offered hay ad libitum. In experiment 1 a fibre-based commercial horse concentrate was incubated in situ using a forward (3, 5, 16, 8, 24, 48 h) or reverse (48, 24, 8, 16, 5, 3 h) incubation sequence. Dry matter (DM), crude protein (CP), neutral-detergent fibre (NDF) and acid-detergent fibre (ADF) degradation coefficients and calculated effective degradability (ED) values were determined. In experiment 2 unmolassed sugar-beet pulp (USBP), hay cubes (HC), soya hulls (SH) and a 2: 1 mixture of oat hulls: naked oats (OHNO) were incubated in situ as for experiment 1. In experiment 3 unprocessed barley (UB), micronized barley (MB), extruded barley (EB) and dehydrated grass (DHG) were incubated in situ according to slightly different forward or reverse incubation sequences of (2, 4, 6, 12, 8, 24, 48 h) and (48, 24, 8, 4, 12, 6, 2 h) respectively. In experiments 2 and 3 only DM degradation parameters were studied.

Of the three starch-based foods studied in experiment 3 (UB, MB and EB), incubation sequence did not significantly P > 0·05) affect any of the degradation parameters examined. Conversely however, of the six fibre-based foods which were examined across the three experiments, incubation sequence did significantly P < 0·05) affect in situ degradation parameters in the commercial horse concentrate in experiment 1, the SH food in experiment 2 and the DHG food in experiment 3. Depending on the food or food constituent studied (i.e. DM, CP, NDF or ADF) degradation coefficients a, b, c and a + b along with ED values calculated at fractional outflow rates of 0·05 and 0·025 could all be statistically different CP < 0·05) according to whether a forward or reverse incubation sequence was used. It is postulated that this effect is related to the basic digestive physiology of the equine caecum which is small, digesta passage rate through it is fast and digesta volumes can vary considerably. These factors may interact to create a considerable degree of non-uniformity within the caecal digesta pool in which in situ bags are incubated. Consequently, it is recommended that in future in situ experiments in the equine hindgut, animals are offered ad libitum diets in an attempt to minimize variation within the caecum. It is also recommended that in situ experimental protocols incorporate more than one incubation sequence when the degradation parameters of fibrous foods are studied in equids.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1999

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.)

Footnotes

Present address: The Agricultural College, Holar in Hjaltadalur, 551 Saudarkrokur, Iceland.

References

Agricultural and Food Research Council. 1992. Technical Committee on Responses to Nutrients. Report no. 9. Nutritive requirements of ruminant animals: protein. Nutrition Abstracts and Reviews, Series B 62: 787835.Google Scholar
Applegate, C. S. and Hershberger, T. V. 1969. Evaluation of in vitro and in vivo caecal fermentation techniques for estimating the nutritive value of forages for equine. Journal of Animal Science 28: 1822.Google Scholar
Argenzio, R. A. 1993. Digestion, absorption and metabolism. In Duke’s physiology of domestic animals, 11th edition (ed. Swenson, M. J. and Reece, W. O.), pp. 325335. Comstock Publishing Associates, Ithaca, USA.Google Scholar
Argenzio, R. A., Lowe, J. E., Pickard, D. W. and Stevens, C.Е. 1974. Digesta passage and water exchange in the equine large intestine. American Journal of Physiology 226: 10351042.Google ScholarPubMed
Association of Official Analytical Chemists. 1990. Official methods of analysis of the Association of Official Analytical Chemists, 15th edition. Association of Official Analytical Chemists, Virginia, USA.Google Scholar
Australian Agricultural Council Ruminants Subcommittee. 1990. Feeding standards for Australian livestock: ruminants. CSIRO, Canberra, Australia.Google Scholar
Dhanoa, M. S. 1988. On the analysis of dacron bag data for low degradability feeds. Grass and Forage Science 43: 441444.CrossRefGoogle Scholar
Drogoul, C., Faurie, F. and Tisserand, J. L. 1995. Estimation of the contribution of the pony’s colon in fibre digestion: a methodological approach. Annales de Zootechnie 44: (supplement) 182.Google Scholar
Goodson, J., Tyznik, W. J., Cline, J. H. and Dehority, B.A. 1988. Effects of an abrupt diet change from hay to concentrate on microbial numbers and physical environment in the caecum of the pony. Applied and Environmental Microbiology 58: 19461950.Google Scholar
Hintz, H. F. 1990. Digestive physiology. In The horse, second edition (ed. J. W. Evans, , Borton, A., Hintz, H. F. and Van Vleck, L. D.), pp. 189207. Freeman and Company, New York, USA.Google Scholar
Howell, C. E. and Cupps, P. T. 1950. Motility patterns of the caecum of the horse. Journal of Animal Science 9: 261268.Google Scholar
Huntington, J. A. and Givens, D. I. 1995a. The in situ technique for studying the rumen degradation of feeds: a review of the procedure. Nutrition Abstracts and Reviews, Series B 65: 6393.Google Scholar
Huntington, J. A. and Givens, D. I. 1995b. The effect of sample preparation and incubation sequence on dry-matter disappearance of fresh grass in situ . Animal Science 60: 512 (abstr.).Google Scholar
Huntington, J. A. and Givens, D. I. 1997. Studies on in situ degradation of feeds in the rumen. 1. Effect of species, bag mobility and incubation sequence on dry matter disappearance. Animal Feed Science and Technology 64: 227241.Google Scholar
Jarrige, R. 1987. Situation and perspectives of the modern protein feeding systems for ruminants. In Feed evaluation and protein requirement systems for ruminants (ed. Jarrige, R. and Alderman, G.), pp. 305326. Commission of the European Communities, Luxembourg.Google Scholar
Lawes Agricultural Trust. 1993. Genstat 5. Rothamsted Experimental Station, Harpenden, Hertfordshire, UK.Google Scholar
Mehrez, A. Z. and 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
Meyer, J. H. F. and Mackie, R. I. 1986. Microbiological evaluation of the intraruminal in sacculus digestion technique. Applied and Environmental Microbiology 51: 622629.CrossRefGoogle ScholarPubMed
Miraglia, N., Martin-Rosset, W. and Tisserand, J. L. 1988. Mesure de la digestibilité des fourrages destinés aux chevaux par la technique des sacs de nylon. Annales de Zootechnie 37: 1320.Google Scholar
Ørskov, E. R. and 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.Google Scholar
Paine, C. A., Crawshaw, R. and Barber, W. P. 1982. A complete exchange method for in sacco estimation of rumen degradability on a routine basis. In Forage protein in ruminant animal production. British Society of Animal Production occasional publication no. 6, pp. 177178.Google Scholar