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A mathematical model of pasture contamination by grazing cattle and the effects on herbage intake

Published online by Cambridge University Press:  27 March 2009

N. R. Brockington
N. R. Brockington
Affiliation:
The Grassland Research Institute, Hurley, Maidenhead, Berkshire
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Summary

A mathematical model has been constructed to simulate pasture contamination by the faeces of grazing cattle and the effects on herbage intake. The model describes the rate of deposition of faeces in relation to herbage intake, the effects of contamination on intake as modified by grazing pressure, and the rate at which the influence of faeces on grazing behaviour declines after deposition.

The information available on these processes is incomplete and imprecise in a number of respects. It appears from the modelling exercise that further data are most urgently needed on the rate at which the inhibitory influence of faeces declines, and on the precise effect of grazing pressure on the amount of herbage rejected.

A secondary effect of contamination is recognized, in which the utilization of herbage initially rejected because of the presence of faeces is modified subsequently because the temporary protection from grazing allows it to become too mature. This effect may be quantitatively larger than the primary contamination effect on untrimmed pastures, but its accurate prediction depends on the establishment of comprehensive relationships between the amount and composition of herbage on offer and intake by the grazing animal. The latter studies deserve at least an equal research priority, in relation to the contamination problem in toto, as the elucidation of the details of the primary effect.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 79 , Issue 2 , October 1972 , pp. 249 - 257
Copyright
Copyright © Cambridge University Press 1972

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References

Anslow, R. C. & Green, J. O. (1967). The seasonal growth of pasture grasses. J. agric. Sci., Camb. 68, 109–22.CrossRefGoogle Scholar
Brennan, R. D. (1967). Programme Reference Manual for 360 CSMP. I.B.M. Application Programme 360-CX-16X.Google Scholar
Brennan, R. D., De Wit, C. T., Williams, W. A. & Quattrin, E. V. (1970). The utility of a digital simulation language for ecological modelling. Oecol. (Berl.) 4, 113–32.CrossRefGoogle Scholar
Brockington, N. R. (1971a). Using models in agricultural research. Span 14, 26–29.Google Scholar
Brockington, N. R. (1971b). An example of mathematical simulation of a biological system. In Grassland Ecology, by Spedding, C. R. W., pp. 196–205. Oxford University Press.Google Scholar
Forrester, J. W. (1961). Industrial Dynamics. U.S.A.: M.I.T. Press.Google Scholar
Garstang, J. R. & Mudd, C. H. (1971). The rejection of contaminated herbage by dairy cows. J. Br. Grassld Soc. 26, 194.Google Scholar
Giöbel, A. & Nillson, N. (1933). Some investigations to throw light on the question of the origin, of ungrazed manure patches and their significance in pastures. Svenska Betes-o. Valför. Årsskr. 15, 159–73.Google Scholar
Greenhalgh, J. F. D., Reid, G. W. & Aitken, J. N. (1967). The effects of grazing intensity on herbage consumption and animal production. II. Longerterm effects in strip-grazed dairy cows. J. agric. Sci., Camb. 69, 217–23.CrossRefGoogle Scholar
Greenhalgh, J. F. D. &Reid, G. W. (1969). The effects of grazing intensity on herbage consumption and animal production. III. Dairy cows grazed at two intensities on clean or contaminated pasture. J. agric. Sci., Camb. 72, 223–28.CrossRefGoogle Scholar
Maclusky, D. S. (1956). Studies in pasture utilization by the grazing animal. Ph.D. Thesis, Univ. of Glasgow.Google Scholar
Maclusky, D. S. (1960). Some estimates of the area of pasture fouled by the excreta of dairy cows. J. Br. Grassld Soc. 15, 181–88.CrossRefGoogle Scholar
Morrey, J. S. (1969). Making the most of high performance grass. Beef and Sheep Fmg 6, (4), 20–23.Google Scholar
Norman, H. J. T. & Green, J. O. (1958). The local influence of cattle dung and urine upon the yield and botanical composition of permanent pasture. J. Br. Grassld Soc. 13, 39–45.CrossRefGoogle Scholar
Petersen, B. G., Lucas, H. L. & Woodhouse, W. W. (1956). The distribution of excreta by freely grazing cattle and its effect on pasture fertility. I. Excrotal distribution. Agron. J. 48, 440–44.CrossRefGoogle Scholar
Pugh, A. L. (1963). Dynamo Users Manual. U.S.A.M.I.T. Press.Google Scholar
Runcie, K. (1961). The zero-grazing of dairy cows. Vet. Eec. 73, 1436–40.Google Scholar
Tayler, J. C. & Large, R. V. (1955). The comparative output of two seeds mixtures. J. Br. Grassld Soc. 10, 341–51.CrossRefGoogle Scholar
De Wit, C. T. (1968). Plant production. Misc. papers Landb. hogesch. Wageningen, No. 3, 25–50.Google Scholar