The NDS Grazing Tool represents a simple approach to the prediction of daily pasture DMI, with more emphasis on animal factors than on sward factors. In facts, sward structure, herbage mass and botanical composition, although known to be important, are not included in the present model for the sake of simplicity.
The tool is able to predict DMI for supplemented and un-supplemented cattle under a wide range of nutritional management conditions and it is useful for applied research, teaching and extension purposes. However, given the variability in management, environment, and other factors out of the control of the Grazing Tool, animal performance expected only provide an idea of the realistic output that can be obtained. The recipe proposed by the tool is based upon the information available on the farm and the user should check carefully the predictions in order to avoid misuse and/or misrepresentation of data.
The NDS Grazing Tool is conceived as an evolving model and will continue to be updated as new researches are conducted and become available, and thanks to the feedback from the user of the NDS Professional platform.
References
F. Bargo, L.D. Muller, J.E. Delahoy, and T.W. Cassidy, 2002. Performance of High Producing Dairy Cows with Three Different Feeding Systems Combining Pasture and Total Mixed Rations - J. Dairy Sci. 85:2948–2963
F. Bargo, L.D. Muller, G.A. Varga, J.E. Delahoy, and T.W. Cassidy, 2002. Ruminal Digestion and Fermentation of High-Producing Dairy Cows with Three Different Feeding Systems Combining Pasture and Total Mixed Rations - J. Dairy Sci. 85:2964–2973
J. Baudracco, N. Lopez-Villalobos, C.W. Holmes, I.M. Brookes, P. Kemp, E. Comoron, L.A. Romero, B. Horan, P. Dillon, and D. Berry, 2006. Development of a model to predict pasture intake for grazing dairy cows in Argentina – Proceedings of the New Zealand Society of Animal Production 2006, Vol 66, 35-41
J. Baudracco , N. Lopez-Villalobos , C.W. Holmes, and K.A. MacDonald. 2010. Effects of stocking rate, supplementation, genotype and their interactions on grazing dairy systems: a review - New Zealand Journal of Agricultural Research Vol. 53, No. 2, June 2010, 109-133
J. Baudracco, N. Lopez-Villalobos, C.W. Holmes, and K.A. MacDonald, 2010. Prediction of herbage dry matter intake for dairy cows grazing ryegrass-based pastures - Proceedings of the New Zealand Society of Animal Production 2010. Vol 70: 80-85
J. Baudracco, N. Lopez-Villalobos, C. W. Holmes, E. A. Comeron, K. A. Macdonald, T. N. Barry and N. C. Friggens, 2012. e-Cow: an animal model that predicts herbage intake, milk yield and live weight change in dairy cows grazing temperate pastures, with and without supplementary feeding - Animal (2012), 6:6, pp 980–993
M. Fajardo, D.A Mattiauda, G. Motta, T.C. Genro, A. Meikle, M. Carriquiry, P. Chilibroste, 2015. Use of mixed rations with different access time to pastureland on productive responses of early lactation Holstein cows – Livestock Science 181 (2015) 51–57
H. Lippke, 1986. Regulation of voluntary intake of ryegrass and sorghum forages in cattle by Indigestible Neutral Detergent Fiber – J. Anim. Sci. 63:1459-1468
D.A. Mattiauda, S. Tamminga, M.J. Gibb, P. Soca, O. Bentancur, P. Chilibroste, 2013. Restricting access time at pasture and time of grazing allocation for Holstein dairy cows: Ingestive behaviour, dry matter intake and milk production - Livestock Science 152 (2013) 53–62
D.R. Mertens, 1987. Predicting intake and digestibility using mathematical models of ruminal function - J. Anim. Sci. 64:1548–1558.
J. W. Penno, K.A. Macdonald, C.W. Holmes, S.R. Davis, G.F. Wilson, I.M. Brookes and E. R. Thom, 2006. Responses to supplementation by dairy cows given low pasture allowances in different seasons 1. Pasture intake and substitution - Animal Science 2006, 82: 661–670
O. P. Vazquez and T. R. Smith, 2000. Factors Affecting Pasture Intake and Total Dry Matter Intake in Grazing Dairy Cows – J. Dairy Sci. 83:2301–2309.