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Using the alkanes and long-chain alcohols of plant cuticular wax to estimate diet composition and the intakes of mixed forages in sheep consuming a known amount of alkane-labelled supplement

Published online by Cambridge University Press:  01 October 2008

H. Dove*
Affiliation:
CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
E. Charmley
Affiliation:
CSIRO Livestock Industries, PO Box 5545, Rockhampton Mail Centre, Qld 4702, Australia
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Abstract

In a feeding trial with 24 sheep, we used the alkanes, long-chain alcohols (LCOH) or both of these plant wax markers, to estimate the diet composition of animals offered diets comprising alkane-labelled cottonseed meal (CSM) together with up to four forages. The diets used were: Diet 1 subterranean clover (Trifolium subterraneum); Diet 2 subterranean clover + phalaris (Phalaris aquatica); Diet 3 subterranean clover, phalaris + annual ryegrass (Lolium rigidum); and Diet 4 subterranean clover, phalaris, annual ryegrass + wheat straw (Triticum aestivum). Estimates of diet composition were made following correction of faecal alkane or LCOH concentrations for incomplete faecal recovery, using recovery estimates derived from individual animals, mean recoveries for a given dietary treatment or grand mean recoveries. Estimated dietary proportions of CSM and known intakes of CSM were used to estimate forage intake. The LCOH concentrations of the diet components were much higher than their alkane concentrations, especially for phalaris. Multivariate analyses showed that the discriminatory information provided by the LCOH was additional to that provided by the alkanes, and that a combination of (LCOH + alkanes) discriminated better between diet components than either class of marker alone. Faecal recoveries of LCOH increased with increasing carbon-chain length; there were no differences in recovery attributable to diet. The most accurate estimates of diet composition were obtained with the combination of (LCOH + alkanes). Estimates of diet composition based on LCOH alone were not as good as alkanes alone, due to the high correlation between the LCOH profiles of phalaris and ryegrass. Total grass content of the diet was very accurately estimated using LCOH. Diet composition estimates provided estimates of whole-diet digestibility, which did not differ from the measured values. Trends in the accuracy of forage intake estimates reflected those found with diet composition and almost two-thirds of estimates based on (LCOH + alkanes) had lower error than those found with alkanes alone. The results confirm that supplements labelled with plant wax components can be used to estimate forage intake, and also show that the LCOH are useful markers for estimating diet composition. Intakes were also computed using a combination of natural LCOH concentrations in the diet and the daily dose rate of even-chain alkanes administered by intra-ruminal device. Differences between intakes so estimated and the measured intakes were closely related to the difference in faecal recovery between the LCOH/alkane pair used to estimate intake, by an amount close to that expected on theoretical grounds. It is concluded that the use of plant wax LCOH, especially in combination with alkanes, will result in improved estimates of diet composition and intake in grazing animals.

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Full Paper
Copyright
Copyright © The Animal Consortium 2008

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References

Ali, HAM, Mayes, RW, Lamb, CS, Verma, AK, Ørskov, ER 2004. The potential of long-chain fatty alcohols and long-chain fatty acids as diet composition markers: development of methods for quantitative analysis and faecal recoveries of these compounds in sheep fed mixed diets. Journal of Agricultural Science 142, 7178.CrossRefGoogle Scholar
Ali, HAM, Mayes, RW, Hector, BL, Verma, AK, Ørskov, ER 2005. The possible use of n-alkanes, long-chain fatty alcohols and long-chain fatty acids as markers in studies of the botanical composition of the diet of free-ranging herbivores. Journal of Agricultural Science 143, 8595.CrossRefGoogle Scholar
Brosh, A, Henkin, Z, Rothman, SJ, Aharoni, Y, Orlov, A, Arieli, A 2003. Effects of faecal n-alkane recovery in estimates of diet composition. Journal of Agricultural Science 140, 93100.CrossRefGoogle Scholar
Bugalho, MN, Dove, H, Kelman, WM, Wood, JT, Mayes, RW 2004. Plant wax alkanes and alcohols as herbivore diet composition markers. Journal of Range Management 57, 259268.CrossRefGoogle Scholar
Charmley, E, Dove, H 2007. Using plant wax markers to estimate diet composition and intakes of mixed forages in sheep by feeding a known amount of alkane-labelled supplement. Australian Journal of Agricultural Research 58, 12151225.CrossRefGoogle Scholar
Dove, H 1992. Using the n-alkanes of plant cuticular wax to estimate the species composition of herbage mixtures. Australian Journal of Agricultural Research 43, 17111724.CrossRefGoogle Scholar
Dove, H, Mayes, RW 1996. Plant wax components: a new approach to estimating intake and diet composition in herbivores. Journal of Nutrition 126, 1326.CrossRefGoogle ScholarPubMed
Dove, H, Mayes, RW 2005. Using n-alkanes and other plant wax components to estimate intake, digestibility and diet composition of grazing/browsing sheep and goats. Small Ruminant Research 59, 123139.CrossRefGoogle Scholar
Dove, H, Mayes, RW 2006. Protocol for the analysis of n-alkanes and other plant-wax compounds and for their use as markers for quantifying the nutrient supply of large mammalian herbivores. Nature Protocols 1, 16801697 (at http://www.nature.com/nprot/journal/v1/n4/index.html).CrossRefGoogle ScholarPubMed
Dove, H, Moore, AD 1995. Using a least-squares optimization procedure to estimate botanical composition based on the alkanes of plant cuticular wax. Australian Journal of Agricultural Research 46, 15341544.CrossRefGoogle Scholar
Dove, H, Scharch, C, Oliván, M, Mayes, RW 2002. Using n-alkanes and known supplement intake to estimate roughage intake in sheep. Animal Production in Australia 24, 5760.Google Scholar
Elwert, C, Dove, H 2005. Estimation of roughage intake in sheep using a known daily intake of a labelled supplement. Animal Science 81, 4756.CrossRefGoogle Scholar
Elwert, C, Dove, H, Rodehutscord, M 2008. Faecal alkane recoveries in multi-component diets and subsequent estimates of diet composition in sheep. Animal 2, 125134.CrossRefGoogle Scholar
Ferreira, LMM, Oliván, M, Garcia, U, Rodrigues, MAM, Osoro, K 2005. Validation of the alkane technique to estimate diet selection of goats grazing heather-gorse vegetation communities. Journal of the Science of Food and Agriculture 85, 16361646.CrossRefGoogle Scholar
Fraser, MD, Theobald, VJ, Moorby, JM 2006. Determining diet composition on complex swards using n-alkanes and long-chain fatty alcohols. Ecological Applications 16, 19011910.CrossRefGoogle ScholarPubMed
GenStat 2005. GenStat, 8th edition. Lawes Agricultural Trust, Rothamsted Experimental Station. VSN International: Oxford, UK.Google Scholar
Mayes, RW, Lamb, CS, and Colgrove, PM 1986. The use of dosed and herbage n-alkanes as markers for the determination of herbage intake. Journal of Agricultural Science, Cambridge 107, 161170.CrossRefGoogle Scholar
Osoro, K, García, U, Jáuregui, BM, Ferreira, LMM, Rook, AJ, Celaya, R 2007. Diet selection and live-weight changes of two breeds of goats grazing on heathlands. Animal 1, 449457.CrossRefGoogle ScholarPubMed
Piasentier, E, Saccà, E, Bovolenta, S 2007. Dietary selection and ingestive behaviour of fallow deer and sheep grazing on adjacent monocultures of white clover and tall fescue. Small Ruminant Research 71, 222233.CrossRefGoogle Scholar
Salt, CA, Mayes, RW, Elston, DA 1992. Effects of season, grazing intensity and diet composition on the radiocaesium intake by sheep on re-seeded hill pasture. Journal of Applied Ecology 29, 378387.CrossRefGoogle Scholar