Preference of sheep among annual legumes is more closely related to plant nutritive characteristics as plants mature
D. T. Thomas A F , J. T. B. Milton B , C. K. Revell C , M. A. Ewing D , R. A. Dynes A , K. Murray E and D. R. Lindsay BA CSIRO Livestock Industries, Private Bag 5, Wembley, WA 6913, Australia.
B School of Animal Biology, The University of Western Australia, Crawley, WA 6009, Australia.
C Department of Agriculture and Food Western Australia, 3 Baron-Hay Court, South Perth, WA 6151, Australia.
D Cooperative Research Centre for Future Farm Industries, The University of Western Australia, Crawley, WA 6009, Australia.
E School of Mathematics and Statistics, The University of Western Australia, Crawley, WA 6009, Australia.
F Corresponding author. Email: dean.thomas@csiro.au
Animal Production Science 50(2) 114-123 https://doi.org/10.1071/AN09082
Submitted: 18 May 2009 Accepted: 17 December 2009 Published: 11 February 2010
Abstract
We hypothesised that the preference of sheep among a wide range of annual legumes at successive stages of plant phenology would be related to laboratory measurements of the chemical composition of the forage. We tested this by examining the relative preferences of sheep among 20 genotypes of annual plants at three phenological stages of plant growth using the Chesson–Manly selection index. Plant material was collected for laboratory analyses at each phenological stage and samples were analysed for nitrogen, sulfur, neutral detergent fibre, acid detergent fibre, in vitro digestibility and water soluble carbohydrates. Sheep differed in relative preference among the plant genotypes within and between each of the three phenological stages. Vegetative characteristics that were correlated with relative preference also differed with plant phenology. Measured characteristics of the plant material explained an increasing proportion of the variance in relative preference with successive phenological stages (4.8, 51.1 and 60.9% at the vegetative, reproductive and senesced stages; P < 0.001). The relative preference of the sheep depended on the overall quality of the vegetation. When the quality of the vegetation was high, relative preference did not correlate well with measured nutritive characteristics. However, when the vegetation was of low quality, sheep selected plants with characteristics associated with higher nutritive value. We conclude that sheep adopt different foraging strategies in response to changing vegetation characteristics and increase their preference for plants that increase their intake of digestible dry matter as the sward matures.
Additional keywords: acceptability, Chesson–Manly selection index, diet selection, lamb, nutritive value, palatability, phenology.
Acknowledgements
We thank Steve Gray, Rob Davidson, Eva Gadja, Chloe Thomas, Matthew Thyer, John Beasley, Georgget Banchero, Simone Martin, Elizabeth Hulm, Leslie Store, Ian Rose and Giles Glasson for their assistance in the field and laboratory, and David Masters and Dean Revell for their valuable comments in the preparation of this manuscript. Dean Thomas was the recipient of an Australian Grains Research and Development Corporation scholarship.
Allden WG, Geytenbeek PE
(1980) Evaluation of nine species of grain legumes for grazing sheep. Proceedings of the Australian Society of Animal Production 13, 249–252.
Bohnert E,
Lascano CE, Weniger JH
(1985) Botanical and chemical composition of the diet selected by fistulated steers under grazing on improved grass-legume pastures in the tropical savannas of Colombia. I. Botanical composition of forage available and selected. Journal of Animal Breeding and Genetics 102, 385–394.
Bohnert E,
Lascano CE, Weniger JH
(1986) Botanical and chemical composition of the diet selected by fistulated steers under grazing on improved grass-legume pastures in the tropical savannas of Colombia. II. Chemical composition of forage available and selected. Journal of Animal Breeding and Genetics 103, 69–79.
Chesson J
(1983) The estimation and analysis of preference and its relationship to foraging models. Ecology 64, 1297–1304.
| Crossref | GoogleScholarGoogle Scholar |
Edwards GR,
Lucas RJ, Johnson MR
(1993) Grazing preference for pasture species is affected by endophyte and nitrogen fertility. Proceedings of the New Zealand Grassland Association 55, 137–141.
Freer M,
Moore AD, Donnelly JR
(1997) GRAZPLAN: decision support systems for Australian grazing enterprises. 2. The animal biology model for feed intake, production and reproduction and the GrazFeed DSS. Agricultural Systems 54, 77–126.
| Crossref | GoogleScholarGoogle Scholar |
Heady HF
(1964) Palatability of herbage and animal preference. Journal of Range Management 17, 76–82.
| Crossref | GoogleScholarGoogle Scholar |
Henry DA,
Simpson RJ, Macmillan RH
(2000) Seasonal changes and the effect of temperature and leaf moisture content on intrinsic shear strength of leaves of pasture grasses. Australian Journal of Agricultural Research 51, 823–831.
| Crossref | GoogleScholarGoogle Scholar |
Jones IH, Hayward MV
(1975) The effect of pepsin pretreatment of herbage on the prediction of dry matter digestibility from solubility in fungal cellulase solutions. Journal of the Science of Food and Agriculture 26, 711–718.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Jung HG, Sahlu T
(1989) Influence of grazing pressure on forage quality and intake by sheep grazing smooth bromegrass. Journal of Animal Science 67, 2089–2097.
Kenney PA, Black JL
(1984) Factors affecting diet selection by sheep. 1. Potential intake rate and acceptability of feed. Australian Journal of Agricultural Research 35, 551–563.
| Crossref | GoogleScholarGoogle Scholar |
Leps J,
Michalek J,
Kulisek P, Uhlik P
(1995) Use of paired plots and multivariate analysis for the determination of goat grazing preference. Journal of Vegetation Science 6, 37–42.
| Crossref | GoogleScholarGoogle Scholar |
Licitra G,
Carpino S,
Schadt I,
Avondo M, Barresi S
(1997) Forage quality of native pastures in a Mediterranean area. Animal Feed Science and Technology 69, 315–328.
| Crossref | GoogleScholarGoogle Scholar |
Manly BFJ,
Miller P, Cook LM
(1972) Analysis of a selective predation experiment. American Naturalist 106, 719–736.
| Crossref | GoogleScholarGoogle Scholar |
Milne JA
(1991) Diet selection by grazing animals. The Proceedings of the Nutrition Society 50, 77–85.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
PubMed |
O’Reagain PJ
(1993) Plant structure and the acceptability of different grasses to sheep. Journal of Range Management 46, 232–236.
| Crossref | GoogleScholarGoogle Scholar |
Provenza FD
(1995) Postingestive feedback as an elementary determinant of food preference and intake in ruminants. Journal of Range Management 48, 2–17.
| Crossref | GoogleScholarGoogle Scholar |
Provenza FD,
Villalba JJ,
Dziba LE,
Atwood SB, Banner RE
(2003) Linking herbivore experience, varied diets, and plant biochemical diversity. Small Ruminant Research 49, 257–274.
| Crossref | GoogleScholarGoogle Scholar |
Ru YJ, Fortune JA
(2000) Variation in nutritive value of plant parts of subterranean clover (Trifolium subterraneum L.). Australian Journal of Experimental Agriculture 40, 397–403.
| Crossref | GoogleScholarGoogle Scholar |
Smit HJ,
Tamminga S, Elgersma A
(2006) Dairy cattle grazing preference among six cultivars of perennial ryegrass. Agronomy Journal 98, 1213–1220.
| Crossref | GoogleScholarGoogle Scholar |
Sweeney RA
(1989) Generic combustion method for determination of crude proteins in feeds: collaborative study. Journal – Association of Official Analytical Chemists 72, 770–774.
|
CAS |
PubMed |
Thomas TA
(1977) An automated procedure for the determination of soluble carbohydrates in herbage. Journal of the Science of Food and Agriculture 28, 639–642.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Walker JW
(1993) Nutritional models for grazing animals. Buvisindi 7, 45–57.
Yemm EW, Willis AJ
(1954) The estimation of carbohydrates in plant extracts by anthrone. Journal of Biochemistry 57, 508–514.
|
CAS |
|
