Hostname: page-component-5d59c44645-mhl4m Total loading time: 0 Render date: 2024-03-02T11:11:19.662Z Has data issue: false hasContentIssue false

Effects of a concentrate supplement on the intake and digestion of a low-quality forage by lambs

Published online by Cambridge University Press:  27 March 2009

P. T. Doyle
Affiliation:
School of Agriculture and Forestry, University of MelbourneParkvilleVictoria 3052Australia
H. Dove
Affiliation:
CSIRO Division of Plant IndustryGPO Box 1600CanberraACT 2601Australia
M. Freer
Affiliation:
CSIRO Division of Plant IndustryGPO Box 1600CanberraACT 2601Australia
F. J. Hart
Affiliation:
School of Agriculture and Forestry, University of MelbourneParkvilleVictoria 3052Australia
R. M. Dixon
Affiliation:
School of Agriculture and Forestry, University of MelbourneParkvilleVictoria 3052Australia
A. R. Egan
Affiliation:
School of Agriculture and Forestry, University of MelbourneParkvilleVictoria 3052Australia

Summary

Weaned lambs of mean weight 25 kg were offered a diet of mature oaten hay or hay supplemented with a pelleted mixture of oat grain and sunflower meal (2:1), at one of three rates, for 86 days. The effect of the supplement on the voluntary intake of hay was measured during the first 20 days when feed was offered twice daily (Expt 1), after which the effects on ruminal and post-ruminal digestion were investigated under continuous feeding conditions (Expt 2).

In Expt 1 the first increment of supplement increased the total intake of organic matter (OM) but increasing the supplement further, up to 510 g D.M., had no additional effect. The voluntary intake of oaten hay was not significantly reduced by the lowest rate of supplementation but at higher rates was depressed at a mean rate of 92 g/100 g supplement. Rates of change in fasted weight on the four treatments were —63, —5, 21 and 45 g/day, respectively.

In Expt 2, where the rates of hay intake were held at 85% of those achieved in Expt 1, the first increment of supplement increased the pool size of OM and cell wall components in the reticulorumen by about 50%. It also increased their outflow rates at the abomasum by 24% and 33%, respectively, but significantly decreased the fractional outflow rate and fractional digestion rate of cell wall components. Supplementation decreased the proportion of apparent OM digestion that occurred in the reticulo-rumen from 76% to 65%. The presence of supplement doubled the ammonia pool in the rumen and increased the abomasal flow on non-ammonia nitrogen (NAN) and microbial NAN by 70%. Estimates of the amounts of crude protein apparently digested in the intestines (DCPi) increased linearly with proportion of supplement in the diet. However, the apparent digestibility of the hay was decreased, rather than increased, by the supplement. Although higher rates of supplement did not significantly change the elevated rumen pools of OM and cell wall components, there was a consistent tendency for these to decrease.

The results are consistent with the view that the intake of unsupplemented hay was limited by its low nitrogen content and the intake of supplemented hay may have been limited primarily by the capacity of the reticulo-rumen, although other factors were increasingly involved at higher rates of supplementation.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1988

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

Aitchison, E., Gill, M., France, J. & Dhanoa, M. S. (1986). Comparison of methods to describe the kinetics of digestion and passage of fibre in sheep. Journal of the Science of Food and Agriculture 37, 10651072.Google Scholar
Allden, W. G. (1969). The summer nutrition of weaner sheep: the voluntary feed intake, body weight change and wool production of sheep grazing the mature herbage of sown pasture in relation to the intake of dietary energy under a supplementary feeding regime. Australian Journal of Agricultural Research 20, 499512.Google Scholar
Association of Official Analytical Chemists (1970). Official Methods of Analysis, 11th Edn. Washington, D.C.: Association of Official Analytical Chemists.Google Scholar
Agricultural Research Council (1980). The Nutrient Requirements of Ruminant Livestock, Technical Review by an Agricultural Research Council Working Party. Farnham Royal: Commonwealth Agricultural Bureaux.Google Scholar
Agricultural Research Council (1984). The Nutrient Requirements of Ruminant Livestock, Supplement No 1. Farnham Royal: Commonwealth Agricultural Bureaux.Google Scholar
Bird, P. R. & Fountain, R. D. (1970). A method for the determination of sulphur in some biological materials. Analyst (London) 95, 98102.Google Scholar
Briggs, P. K., Hogan, J. P. & Reid, R. L. (1957). The effect of volatile fatty acids, lactic acid and ammonia on rumen pH in sheep. Australian Journal of Agricultural Research 8, 674690.Google Scholar
Bruce, J., Goodall, E. D., Kay, R. N. B., Phillipson, A. T. & Vowles, L. E. (1966). The flow of organic and inorganic materials through the alimentary tract of the sheep. Proceedings of the Royal Society, London, B 166, 4662.Google Scholar
Coombe, J. B. (1985). Rape and sunflower seed meals as supplements for sheep fed on oat straw. Australian Journal of Agricultural Research 36, 717728.Google Scholar
Downes, A. M. & McDonald, I. W. (1964). The chromium 51 complex of ethylenerdiamine tetra-acetic acid as a soluble rumen marker. British Journal of Nutrition 18, 153162.Google Scholar
Doyle, P. T., Egan, J. K., McLaren, C. E. & Egan, A. R. (1984). Comparison of two double-marker systems used in studies of digesta flow at the abomasum. In Techniques in Particle Size Analysis of Feed and Digesta in Ruminants (ed. Kennedy, P. M.), Occasional Publication No. 1, p. 178. Edmonton, Alberta: Canadian Society of Animal Science.Google Scholar
Egan, A. R. (1970). Nutritional status and intake regulation in sheep. VI. Evidence for variation in setting of an intake regulatory mechanism relating to the digesta content of the reticulo-rumen. Australian Journal of Agricultural Research 21, 735746.Google Scholar
Egan, J. K. & Doyle, P. T. (1984). A comparison of particulate markers for the estimation of digesta flow from the abomasum of sheep offered chopped oaten hay. Australian Journal of Agricultural Research 35, 279291.Google Scholar
Egan, J. K. & Doyle, P. T. (1985). Effect of intraruminal infusion of urea on the response in voluntary food intake by sheep. Australian Journal of Agricultural Research 36, 483495.Google Scholar
Egan, J. K., Pearce, G. R., Doyle, P. T. & Thomas, R. (1983). Measurement of the quantity and composition of digesta in the reticulo-rumen of sheep fed a roughage diet. Australian Journal of Agricultural Research 34, 307315.Google Scholar
El-Shazly, K., Dehority, B. A. & Johnson, R. R. (1961). Effect of starch on the digestion of cellulose in vitro and in vivo by rumen micro-organisms. Journal of Animal Science 20, 268273.Google Scholar
Erwin, E. S., Marco, G. J. & Emery, E. M. (1961). Volatile fatty acid analysis of blood and rumen fluid by gas chromatography. Journal of Dairy Science 44, 17681771.Google Scholar
Faichney, G. J. (1975). The use of markers to partition digestion within the gastro-intestinal tract of ruminants. In Digestion and Metabolism in the Ruminant (ed. McDonald, I. W. & Warner, A. C. I.), pp. 277291. Armidale: University of New England Publishing Unit.Google Scholar
Faichney, G. J. (1980). Measurement in sheep of the quantity and composition of rumen digesta and of the fractional outflow rates of digesta constituents. Australian Journal of Agricultural Research 31, 11291137.Google Scholar
Foot, J. Z., McIntyre, J. S. & Heazlewood, P. G. (1983). Supplements for Merino weaner sheep grazing mature pastures in summer and autumn. Australian Journal of Experimental Agriculture and Animal Husbandry 23, 374382.Google Scholar
Freer, M. & Campling, R. C. (1963). Factors affecting the voluntary intake of food by cows. 5. The relationship between the voluntary intake of food, the amount of digesta in the reticulo-rumen and the rate of disappearance of digesta from sthe alimentary tract with diets of hay, dried grass or concentrates. British Journal of Nutrition 17, 7988.Google Scholar
Freer, M. & Jones, D. B. (1984). Feeding value of subterranean clover, lucerne, phalaris and Wimmera ryegrass for lambs. Australian Journal of Experimental Agriculture and Animal Husbandry 24, 156164.Google Scholar
Freer, M., Dove, H., Axelsen, A., Donnelly, J. R. & McKinney, G. T. (1985). Responses to supplements by weaned lambs grazing mature pasture or eating hay in yards. Australian Journal of Experimental Agriculture and Animal Husbandry 25, 289297.Google Scholar
Freer, M., Dove, H., Axelsen, A. & Donnelly, J. R. (1988). Responses to supplements by weaned lambs when grazing mature pasture or eating hay cut from the same pasture. Journal of Agricultural Science, Cambridge 110, 661667.Google Scholar
Goering, H. K. & Van Soest, P. J. (1970). Forage Fiber Analyses, USD A Handbook No. 379. Washington, D.C.: U.S. Department of Agriculture.Google Scholar
Hodge, R. W. & Bogdanovic, B. (1983). Feeding hay supplemented with peas or low protein oats to crossbred lambs born in the spring. Australian Journal of Experimental Agriculture and Animal Husbandry 23, 1923.Google Scholar
Hynd, P. I. (1984). Effects of starch fermentation products on roughage digestion. Journal of Agricultural Science, Cambridge 103, 469470.Google Scholar
MacRae, J. C. & Armstrong, D. G. (1969). Studies on intestinal digestion in the sheep. 2. Digestion of some carbohydrate constituents in hay, cereal and hay-cereal rations. British Journal of Nutrition 23, 377387.Google Scholar
Milford, R. & Minson, D. J. (1966). Intake of tropical pasture species. Proceedings of the 9th International Grassland Congress, São Paulo, pp. 815822.Google Scholar
Moir, R. J. & Somers, M. (1957). Rumen flora studies. VIII. The influence of rate and method of feeding a ration upon its digestibility, upon rumen function and upon the ruminal population. Australian Journal of Agricultural Research 8, 253265.Google Scholar
Mould, F. L. & Ørskov, E. R. (19831984). Manipulation of rumen fluid pH and its influence on cellulolysis in sacco, dry matter degradation and the rumen microflora in sheep offered either hay or concentrates. Animal Feed Science and Technology 10, 114.Google Scholar
Roberts, G. B., Kenney, P. A. & Reeve, J. L. (1979). Effect of lupin grain and recently cut lucerne on intake and digestibility of mature weathered herbage by Border Leicester × Merino ewes. Australian Journal of Experimental Agriculture and Animal Husbandry 19, 156160.Google Scholar
Tan, T. N., Weston, R. H. & Hogan, J. P. (1971). Use of 103Ru-labelled tris (1, 10-phenanthroline) ruthenium (II) chloride as a marker in digestion studies with sheep. International Journal of Applied Radiation and Isotopes 22, 301308.Google Scholar
Ulyatt, M. J., Waghorn, G. C., John, A., Reid, C. S. W. & Monro, J. (1984). Effect of intake and feeding frequency on feeding behaviour and quantitative aspects of digestion in sheep fed chaffed lucerne hay. Journal of Agricultural Science, Cambridge 102, 645657.Google Scholar
Van Soest, P. J. (1963). Use of detergents in the analysis of fibrous feeds. II. A rapid method for the determination of fiber and lignin. Journal of the Association of Official Agricultural Chemists 46, 829835.Google Scholar
Weston, R. H. (1985). The regulation of feed intake in herbage-fed ruminants. Proceedings of the Nutrition Society of Australia 10, 5562.Google Scholar
Weston, R. H. (1988). Factors limiting the intake of feed by sheep. X. The effects of concentrate supplements on the voluntary consumption and digestion of a medium quality roughage. Australian Journal of Agricultural Research 39, 255271.Google Scholar