Hostname: page-component-7bb8b95d7b-wpx69 Total loading time: 0 Render date: 2024-09-15T19:23:44.623Z Has data issue: false hasContentIssue false

The proportions of cell content, nitrogen, nitrate-nitrogen and water-soluble carbohydrate in three grasses in the early stages of regrowth after defoliation with and without applied nitrogen

Published online by Cambridge University Press:  27 March 2009

D. Wilman
Affiliation:
Department of Agriculture, University College of Wales, Aberystwyth
P. T. Wright
Affiliation:
Department of Agriculture, University College of Wales, Aberystwyth

Summary

The regrowth of Aberystwyth S. 22 Italian ryegrass, S. 24 perennial ryegrass and S. 37 cocksfoot was studied in field swards with and without applied nitrogen during the 21 days following a cut or grazing, there being a total of five periods of study at different tunes of year and in different years.

The proportion of cell content in the harvested herbage, as measured by neutral detergent, increased by nearly 9 percentage units from day 3 to day 18 of regrowth. The proportion of cell content as measured by acid pepsin also increased during regrowth, but to a lesser extent. The proportion of cell content in leaf blades of two age categories, as measured by neutral detergent, also increased during regrowth. The above increases in proportion of cell content were found in all three grasses. The increases were associated with increases in the proportion of crude protein in dry matter, which were only partially offset by reductions in the proportion of water-soluble carbohydrate. The broad pattern of change in N and nitrate-N content of Italian ryegrass herbage during regrowth in spring with different amounts of N applied, noted in earlier experiments, was confirmed and found to apply to perennial ryegrass and cocksfoot also. During a September-October period of study there was little sign of decline in nitrate-N content within the 21 days where N had been applied. Younger leaf blades had a rather lower nitrate-N content and a slightly higher total N content, on average, than, older blades. The application of N increased the proportion of crude protein more than it reduced the proportion of water-soluble carbohydrate and it increased the proportion of cell content. The increase in proportion of cell content was sufficient to explain the positive effect of N application on digestibility. The average proportion of total herbage N which was found in the cell wall fraction was about 12%.

There appeared to be a relationship between chemical composition and dry-matter content. The chlorophyll content of leaf blades increased during regrowth and was increased by N application. The experimental results on balance, particularly those for proportion of cell content, suggest an improvement in nutritive value of grass during regrowth up to about 3 weeks in contrast to the well-recognized decline in nutritive value where regrowth proceeds beyond about 3 weeks.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1978

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

Agricultural Research Council (1965). The Nutrient Requirements of Farm Livestock. No. 2, Ruminants, pp. 264. London: Agricultural Research Council.Google Scholar
Faithtull, N. T. (1971). Automated simultaneous determination of nitrogen, phosphorus, potassium and calcium on the same herbage digest solution. Laboratory Practice 20, 4144.Google Scholar
Follett, M. J. & Raiciut, P. W. (1963). Determination of nitrite and nitrate in meat products. Journal of the Science of Food and Agriculture 14, 138144.CrossRefGoogle Scholar
Ojuederie, B. M. (1974). Effects of nitrogenous fertilizer on grass growth. Ph.D. thesis, University College of Wales, Aberystwyth.Google Scholar
Osbourn, D. F., Terry, R. A., Outen, G. E. & Cammell, S. B. (1974). The significance of a determination of cell walls as the rational basis for the nutritive evaluation of forages. Proceedings XII International Grassland Congress, Moscow, vol. III, 374380.Google Scholar
Terry, R. A. & Tilley, J. M. A. (1964). The digestibility of the leaves and stems of perennial ryegrass, cocksfoot, timothy, tall fescue, lucerne and sainfoin, as measured by an in vitro procedure. Journal of the British Grassland Society 19, 363372.CrossRefGoogle Scholar
Thomas, T. A. (1977). An automated procedure for the determination of soluble carbohydrates in herbage. Journal ef the Science of Food and Agriculture 28, 639642.CrossRefGoogle Scholar
Tilley, J. M. A. & Terry, R. A. (1969). The relationship between the soluble constituents of herbage and their dry-matter digestibility. Journal of the British Grassland Society 24, 290296.CrossRefGoogle Scholar
Van Soest, P. J. & Wine, R. H. (1967). Use of detergents in the analysis of fibrous feeds. IV. Determination of plant cell-wall constituents. Journal of the Association of Official Analytical Chemists 50, 5055.Google Scholar
Wilman, D. (1965). The effect of nitrogenous fertilizer on the rate of growth of Italian ryegrass. Journal of the British Grassland Society 20, 248254.CrossRefGoogle Scholar
Wilman, D. (1970a). The effect of nitrogenous fertilizer on the rate of growth of Italian ryegrass. 2. Growth up to 10 weeks: dry-matter yield and digestibility. Journal of the British Grassland Society 25, 154161.CrossRefGoogle Scholar
Wilman, D. (1970b). The effect of nitrogenous fertilizer on the rate of growth of Italian ryegrass. 3. Growth up to ten weeks: nitrogen content and yield. Journal of the British Grassland Society 25, 242245.CrossRefGoogle Scholar
Wilman, D. (1975). Nitrogen and Italian ryegrass. 2. Growth up to 14 weeks: nitrogen, phosphorus and potassium content and yield. Journal of the British Grassland Society 30, 243249.CrossRefGoogle Scholar
Wilman, D., Koocheki, A. & Lwoga, A. B. (1976a). The effect of interval between harvests and nitrogen application on the proportion and yield of crop fractions and on the digestibility and digestible yield and nitrogen content and yield of two perennial ryegrass varieties in the second harvest year. Journal of Agricultural Science, Cambridge 87, 5974.CrossRefGoogle Scholar
Wilman, D., Ojuederie, B. M. & Asare, E. O. (1976b). Nitrogen and Italian ryegrass. 3. Growth up to 14 weeks: yields, proportions, digestibilities and nitrogen contents of crop fractions, and tiller populations. Journal of the British Grassland Society 31, 7379.CrossRefGoogle Scholar
Wilman, D., Daly, M., Koocheki, A. & Lwoga, A. B. (1977a). The effect of interval between harvests and nitrogen application on the proportion and digestibility of cell wall, cellulose, hemi-cellulose and lignin and on the proportion of lignified tissue in leaf crosssection in two perennial ryegrass varieties. Journal of Agricultural Science, Cambridge 89, 5363.CrossRefGoogle Scholar
Wilman, D., Koocheki, A., Lwoga, A. B. & Samaan, S. F. (1977b). Digestion in vitro of Italian and perennial ryegrasses, red clover, white clover and lucerne. Journal of the British Grassland Society 32, 1324.CrossRefGoogle Scholar
Wilman, D. & Weight, P. T. (1978). Dry-matter content, leaf water potential and digestibility of three grasses in the early stages of regrowth after defoliation with and without applied nitrogen. Journal of Agricultural Science, Cambridge 91, 365380.CrossRefGoogle Scholar
Wright, P. T. (1977). Studies of regrowth after defoliation and of response to nitrogen in grasses. Ph.D. thesis, University College of Wales, Aberystwyth.Google Scholar