Variation within and between two saltbush species in plant composition and subsequent selection by sheepHayley C. Norman A C , Colby Freind B , David G. Masters A , Allan J. Rintoul A , Robyn A. Dynes A and Ian H. Williams B
A CSIRO Livestock Industries, Centre for Environment and Life Sciences, Private Bag 5, Wembley, WA 6913, Australia; and Cooperative Research Centre for Plant-based Management of Dryland Salinity, University of Western Australia, Crawley, WA 6009, Australia.
B School of Animal Biology, Faculty of Natural and Agricultural Sciences, University of Western Australia, Crawley, WA 6009, Australia.
C Corresponding author. Email: Hayley.Norman@csiro.au
Australian Journal of Agricultural Research 55(9) 999-1007 https://doi.org/10.1071/AR04031
Submitted: 10 February 2004 Accepted: 4 August 2004 Published: 24 September 2004
This work examines nutritive value and preference by sheep of 2 saltbush species, river saltbush (Atriplex amnicola) and old man saltbush (Atriplex nummularia). Both species are woody perennials that are native to Australia and used in commercial grazing systems. The hypothesis for this study was that sheep will graze saltbushes with higher nutritive value and lower secondary compounds in preference to bushes with lower nutritive value and higher secondary compounds. This was expected to be found both within and between the old man and river saltbush species.
To test the hypothesis, 10-month-old Merino ewes grazed a 10-ha plot containing a mixture of old man and river saltbush in approximately equal proportions. Within the plot, and prior to grazing, 20 bushes of each species were pegged for identification and samples of edible plant material collected for analysis. Each week during the grazing period the bushes were photographed for assessment of preference. Sheep preferred river saltbush to old man saltbush and also showed some preferences for specific bushes within each species. Differences in digestibility of dry matter and organic matter, crude protein, ash, oxalates, and nitrates were not clearly associated with differences in preference. Although the reasons for preferences were not demonstrated, the analysis of the plant material did indicate that the content of total ash and oxalates was at levels likely to depress voluntary feed intake.
Additional keywords: shrub biomass, salinity, preference, feed intake, protein, ADF, sulfur, oxalate.
Thanks to Tony, Donna, and Simon York for the use of their pasture and sheep. Thank you to Simone Martin, Mike Carthew, Elizabeth Hulm, Nathan Phillips, Judy Williams, Matt Wilmot, Lesley Store, Rob Kelly, and Emma Bermingham. This research was partially supported by Land Water & Wool.
Andrew MH, Noble IR, Lange RT (1979) A non-destructive method for estimating the weight of forage on shrubs. Australian Rangeland Journal 1, 225–231.
Barry TN, McNabb WC (1999) The implications of condensed tannins on the nutritive value of temperate forages fed to ruminants. The British Journal of Nutrition 81, 263–272.
| PubMed |
Bird PR (1972) Sulfur metabolism and excretion studies in ruminants. 10. Sulphide toxicity in sheep. Australian Journal of Biological Sciences 25, 1087–1098.
| PubMed |
Briens M, Larher F (1982) Osmoregulation in halophytic higher plants: a comparative study of soluble carbohydrates, polyols, betaines and free proline. Plant, Cell and Environment 5, 287–292.
Burritt EA, Provenza FD (2000) Role of toxins in intake of varied diets by sheep. Journal of Chemical Ecology 26, 1991–2005.
| CrossRef |
Duncan AJ, Hartley SE, Iason GR (1994) Fine-scale discrimination of forage quality by sheep offered a soybean meal or barley supplement while grazing a N-fertilized heather (Calluna vulgaris) mosaic. Journal of Agricultural Science (Cambridge) 123, 363–370.
Faichney, GJ , and White, GA (1983).
Forbes JM (1999) Minimal total discomfort as a concept for the control of food intake and selection. Appetite 33, 371.
| CrossRef | PubMed |
Forbes JM, Mayes RW (2002) Food choice. ‘Sheep nutrition’. (Eds M Freer, H Dove) pp. 51–69. (CSIRO Publishing: Collingwood, Vic.)
Gihad EA, El Shaer HM (1994) Utilization of halophytes by livestock on rangelands. Problems and prospects. ‘Halophytes as a resource for livestock and for rehabilitation of degraded land’. (Eds V Squires, AT Ayoub) pp. 77–96. (Kluwer Academic Publishers: Dordrecht, The Netherlands)
Hills J, Nolan JV, Hinch GN, Lynch JJ (1998)
Ilarslan H, Palmer RG, Imsande J, Horner HT (1997) Quantitative determination of calcium oxalate and oxalate in developing seed of soybean (Leguminosae). American Journal of Botany 84, 1042–1046.
Klein L, Baker SB (1993) Composition of the fractions of dry, mature subterranean clover digested in vivo and in vitro. ‘Proceedings of the XVII International Grasslands Congress’. (New Zealand Grasslands Association: Palmerston North, NZ)
Kyriazakis I, Oldham JD (1993) Diet selection in sheep: the ability of growing lambs to select a diet that meets their crude protein (N × 6.25) requirements. The British Journal of Nutrition 69, 617–629.
| PubMed |
Kyriazakis I, Papachristou TG, Duncan AJ, Gordon IJ (1997) Mild conditioned food aversions developed by sheep towards flavours associated with plant secondary compounds. Journal of Chemical Ecology 23, 727–746.
| CrossRef |
Leigh JH (1986) Forage value and utilisation of chenopod dominated shrubland. Reclamation and Revegetation Research 5, 387–402.
Li YG, Tanner G, Larkin P (1996) The DMACA-HCl protocol and the threshold proanthocyanidin content for bloat safety in forage legumes. Journal of the Science of Food and Agriculture 70, 89–101.
| CrossRef |
Masters DG, Norman HC, Dynes RA (2001) Opportunities and limitations for animal production from saline land. Asian-Australasian Journal of Animal Science 14, 199–211.
McQuaker NR, Brown DF, Kluckner PD (1979) Digestion of environmental materials for analysis by Inductively Coupled Plasma-Atomic Emission Spectrometry. Analytical Chemistry 51, 1082–1084.
Morecombe PW, Young GE, Boase KA (1996) Grazing a saltbush (Atriplex-Maireana) stand by Merino wethers to fill the ‘autumn feed-gap’ experienced in the Western Australian wheat belt. Australian Journal of Experimental Agriculture 36, 641–647.
National Land and Water Resources Audit (2001).
Pol JE (1980) Utilization of saltbush as feed for sheep. Honours thesis, University of Western Australia, Perth.
Poppy GM (1999) The raison d'être of secondary plant chemicals? Trends in Plant Science 4, 82–83.
| CrossRef |
Provenza FD (1995) Post ingestive feedback as an elementary determinant of food preference and intake in ruminants. Journal of Range Management 48, 2–17.
Provenza FD, Kimball BA, Villalba JJ (2000) Roles of odor, taste, and toxicity in the food preferences of lambs: implications for mimicry in plants. Oikos 88, 424–432.
Provenza FD, Pfister JA (1991) Influence of plant toxins on food ingestion by herbivores. ‘Recent advances on the nutrition of herbivores’. (Eds YW Ho, HK Wong, N Abdullah, ZA Tajuddin) pp. 199–206. (Malaysian Society of Animal Production: Kuala Lumpur)
Repp WW, Hale WH, Cheng EW, Burroughs W (1955) The influence of oral administration of non-protein N feeding compounds upon blood ammonia and urea levels in lambs. Journal of Animal Science 14, 118–131.
Runciman, HV , and Malcolm, CV (1989).
Standing Committee on Agriculture (1990).
Storey R, Ahmad N, Wyn Jones RG (1977) Taxonomic and ecological aspects of the distribution of glycinebetaine and related compounds in plants. Oecologia 27, 319–332.
| CrossRef |
Suiter J (1994) Body condition scoring of sheep and goats. Farmnote 69/1994. Department of Agriculture, Western Australia.
Sweeney RA, Rexroad PR (1987) Comparison of LECO FP-228 ‘N Determinator’ with AOAC copper catalyst Kjeldahl method for crude protein. Journal – Association of Official Analytical Chemists 70, 1028–1032.
Warren BE, Casson T (1994) Sheep and saltbush — are they compatible? ‘Productive Use and Rehabilitation of Saline Lands, 3rd National Conference’. Echuca, Vic. (Promaco Conventions Pty Ltd)
Wilson AD (1966) The tolerance of sheep to sodium chloride in food or drinking water. Australian Journal of Agricultural Research 17, 503–514.
| CrossRef |
Zall DM, Fisher D, Garner MQ (1959) Photometric determination of chlorides in water. Analytical Chemistry 28, 1665–1668.