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Influence of sward height and advancing season on rumen fermentation in Merino sheep grazing grass/white clover pasture

Published online by Cambridge University Press:  18 August 2016

M.D. Carro ,
M.J. Ranilla ,
F.J. Giráldez ,
A.R. Mantecón  and
J.S. González
M.D. Carro
Affiliation:
Departamento de Producción Animal l, Universidad de León, 24007 León, Spain
M.J. Ranilla
Affiliation:
Departamento de Producción Animal l, Universidad de León, 24007 León, Spain
F.J. Giráldez
Affiliation:
Estación Agrícola Experimental, Consejo Superior de Investigaciones Científicas, Apartado, 788, 24080 León, Spain
A.R. Mantecón
Affiliation:
Estación Agrícola Experimental, Consejo Superior de Investigaciones Científicas, Apartado, 788, 24080 León, Spain
J.S. González
Affiliation:
Departamento de Producción Animal l, Universidad de León, 24007 León, Spain
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Abstract

The study was carried out on a continuously stocked grass/white clover pasture, which was maintained at two sward heights: 3·5 cm (low; LSH) and 6·5 cm (high; HSH). Three oesophageal-cannulated and three other rumen-cannulated Merino sheep were allocated to each of the plots (LSH and HSH) in order to study the effects of sward height and advancing grazing season on rumen fermentation in grazing sheep. Three grazing periods (13 days) were considered: mid June, late July and early October. During each grazing period and after a preliminary period (7 days), samples of the grazed herbage and of grass hay were incubated in nylon bags in the rumen of each sheep for 0, 3, 6, 12, 24, 48, 72 and 96 h. On days 10 and 12 rumen fluid was sampled at the incubation time (11.00 h) and at 3, 6 and 12 h afterwards and pH, ammonia-nitrogen and volatile fatty acids (VFA) concentrations were determined. Sward height did not affect (P > 0·05) the degradation rate of dry matter (DM) and neutral-detergent fibre (NDF) from grazed herbage in any of the considered periods. Animals grazing LSH presented higher (P < 0·05) DM and NDF effective degradabilities (DMED and NDFED, respectively) during October but no differences were found during June and July. HSH grazing animals presented lower (P < 0·05) degradation rates of DM and NDF from grass hay during June and July than those found for LSH grazing sheep, with no differences (P > 0·05) observed during October. Sward height did not affect (P > 0·05) grass hay DMED and NDFED during July but during June and October HSH grazing sheep presented higher (P < 0·05) values. In general, DMED and NDFED from grazed herbage increased with advancing season, the lowest (P < 0·05) value being observed during June. Rumen ammonia-nitrogen concentrations were higher during October than during June and July for both sward heights but values were higher than 200 mg/l at any sampling time during all grazing seasons. Rumen pH values were within the range considered adequate for maintaining a normal cellulolytic activity at most of the sampling times, with the exception of sheep grazing LSH during October. Rumen VFA concentrations were within the range reported for other grazing studies and only a few differences between sward heights were found. Differences in rumen parameters are discussed in relation to both chemical composition of grazed herbage and pattern of intake.

Keywords

grazing timerumen fermentationsheepsward height
Type
Research Article
Information
Animal Science , Volume 68 , Issue 4 , June 1999 , pp. 779 - 788
Copyright
Copyright © British Society of Animal Science 1999

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References

Arnold, G.W. 1981. Grazing behaviour. In Grazing animals (World Animal Science Bl) (ed. Morley, F.H.W.), pp. 79–104. Elsevier Scientific Publishing Company, Amsterdam.Google Scholar
Association of Official Analytical Chemists. 1990. Official methods for analysis of the Association of Official Analytical Chemists, 15th edition. Association of Official Analytical Chemists, Washington, DC.Google Scholar
Barthram, G. T. 1986. Experimental techniques: the HFRO sward stick. Biennial report. Hill Farming Research Organisation 1984-85,pp. 29–30.Google Scholar
Beever, D. E., Losada, H. R., Cammell, S.B., Evans, R. T. and Haines, M. J. 1986. Effect of forage species and season on nutrient digestion and supply in grazing cattle. British Journal of Nutrition 56: 209–225.Google Scholar
Berggren-Thomas, B. and Hohenboken, W. D. 1986. The effects of sire-breed, forage availability and weather on the grazing behavior of crossbred ewes. Applied Animal Behaviour Science 15: 217–228.Google Scholar
Church, D.C. 1991. Livestock feeds and feeding, third edition. Regents / Prentice Hall, Englewood Cliffs, New Jersey.Google Scholar
Cruickshank, G.J., Poppi, D.P. and Sykes, A.R. 1992. The intake, digestion and protein degradation of grazed herbage by early-weaned lambs. British Journal of Nutrition 68: 349–364.Google Scholar
García, M. A., Isac, M. D., Aguilera, J. F. and Molina Alcaide, E. 1994. Rumen fermentation pattern in goats and sheep grazing pastures from semiarid Spanish lands unsupplemented or supplemented with barley grain or barley grain-urea. Livestock Production Science 39: 81–84.Google Scholar
Goering, H. K. and Van Soest, P.J. 1970. Forage fiber analysis (apparatus, reagents, procedures and some applications). Agricultural handbook no. 379. Agricultural Research Service, United States Department of Agriculture, Washington, DC.Google Scholar
Gong, Y., Lambert, M. G. and Hodgson, J. 1996. Effects of contrasting sward heights within forage species on short-term ingestive behaviour of sheep and goats grazing grasses and legumes. New Zealand Journal of Agricultural Research 39: 83–93.CrossRefGoogle Scholar
McDonald, P., Stirling, A.C., Henderson, A. R., Dewar, W. A., Stark, G. H., Davie, W. G., Macpherson, H. T., Reid, A. M. and Slater, J. 1960. Studies on ensilage. Technical bulletin, no. 24, Edinburgh School of Agriculture, pp. 183.Google Scholar
Mantecón, A. R., Jaramillo, E., Frutos, P. and Lavín, P. 1995. Effect of sward height and sheep breed on sward composition during summer grazing period. Animal Science 60: 532 (abstr.).Google Scholar
Mehrez, A. L., Ørskov, E.R. and McDonald, I. 1977. Rates of rumen fermentation in relation to rumen ammonia concentration. British Journal of Nutrition 38: 437–443.CrossRefGoogle Scholar
Olson, K.C., Caton, J.S., Kirby, D.R. and Norton, P.L. 1994. Influence of yeast culture supplementation and advancing season on steers grazing mixed-grass prairie in the northern great plains. II. Ruminai fermentation, site of digestion, and microbial efficiency. Journal of Animal Science 72: 2158–2170.Google Scholar
Ørskov, E.R., Hoveli, F.D.DeB. and Mould, F. 1980. The use of the nylon bag technique for the evaluation of feedstuffs. Tropical Animal Production 5: 195–213.Google Scholar
Ranilla, M.J., Carro, M.D., Valdés, C., Giráldez, F.J. and López, S. 1997. A comparative study of ruminal activity in Churra and Merino sheep offered alfalfa hay. Animal Science 65: 121–128.Google Scholar
Satter, L. D. and Slyter, L. L. 1974. Effect of ammonia concentration on rumen microbial protein in vitro. British Journal of Nutrition 32: 199–208.CrossRefGoogle Scholar
Statistical Analysis Systems Institute. 1997. SAS companion for the Microsoft Windows Environment, version 6. SAS Institute Inc., Cary, NC.Google Scholar
Steel, R.G.C. and Torrie, J.H. 1980. Principles and procedures of statistics, second edition. McGraw-Hill, New York.Google Scholar
Stewart, C.S. 1977. Factors affecting cellulolytic activity of rumen contents. Applied Environmental Microbiologi/ 33: 497–502.Google Scholar
Valdés, C., Mantecón, A.R., Giráldez, F.J. and Bermúdez, F.F. 1995. Herbage intake by Churra ewes grazing at two different sward heights. Journal of Animal and Feed Sciences 4: 1–9.Google Scholar
Van Soest, P. J. 1994. Nutritional ecology of the ruminant, second edition. Cornell University Press, Ithaca, New York.CrossRefGoogle Scholar