Modelling Pasture-based Automatic Milking System Herds: The Impact of Large Herd on Milk Yield and Economics

  • Islam, M.R. ;
  • Clark, C.E.F. ;
  • Garcia, S.C. ;
  • Kerrisk, K.L.
  • Received : 2014.05.21
  • Accepted : 2014.10.25
  • Published : 2015.07.01


The aim of this modelling study was to investigate the effect of large herd size (and land areas) on walking distances and milking interval (MI), and their impact on milk yield and economic penalties when 50% of the total diets were provided from home grown feed either as pasture or grazeable complementary forage rotation (CFR) in an automatic milking system (AMS). Twelve scenarios consisting of 3 AMS herds (400, 600, 800 cows), 2 levels of pasture utilisation (current AMS utilisation of 15.0 t dry matter [DM]/ha, termed as 'moderate'; optimum pasture utilisation of 19.7 t DM/ha, termed as 'high') and 2 rates of incorporation of grazeable complementary forage system (CFS: 0, 30%; CFS = 65% farm is CFR and 35% of farm is pasture) were investigated. Walking distances, energy loss due to walking, MI, reduction in milk yield and income loss were calculated for each treatment based on information available in the literature. With moderate pasture utilisation and 0% CFR, increasing the herd size from 400 to 800 cows resulted in an increase in total walking distances between the parlour and the paddock from 3.5 to 6.3 km. Consequently, MI increased from 15.2 to 16.4 h with increased herd size from 400 to 800 cows. High pasture utilisation (allowing for an increased stocking density) reduced the total walking distances up to 1 km, thus reduced the MI by up to 0.5 h compared to the moderate pasture, 800 cow herd combination. The high pasture utilisation combined with 30% of the farm in CFR in the farm reduced the total walking distances by up to 1.7 km and MI by up to 0.8 h compared to the moderate pasture and 800 cow herd combination. For moderate pasture utilisation, increasing the herd size from 400 to 800 cows resulted in more dramatic milk yield penalty as yield increasing from c.f. 2.6 and 5.1 kg/cow/d respectively, which incurred a loss of up to $AU 1.9/cow/d. Milk yield losses of 0.61 kg and 0.25 kg for every km increase in total walking distance (voluntary return trip from parlour to paddock) and every one hour increase in MI, respectively. The high pasture utilisation combined with 30% of the farm in CFR in the farm increased milk yield by up to 1.5 kg/cow/d, thereby reducing loss by up to $0.5/cow/d (c.f. the moderate pasture and 800 cow herd scenario). Thus, it was concluded that the successful integration of grazeable CFS with pasture has the potential to improve financial performance compared to the pasture only, large herd, AMS.


Automatic Milking System;Complementary Forage System;Herd Size;Walking Distance;Milking Interval;Milk Yield;Profit


  1. Islam, M. R., S. C. Garcia, C. E. F. Clark, and K. L. Kerrisk. 2015b. Modelling pasture-based automatic milking system herds: system fitness of grazeable home-grown forages, land areas and walking distances. Asian Australas. J. Anim. Sci. 28:903-910.
  2. Jagtenberg, K. and J. van Lent. 2000. Milking robots and grazing. Praktijkonderzoek Rundvee, Schapen en Paarden. 13:7-9.
  3. Lyons, L., K. L. Kerrisk, and S. C. Garcia. 2014. Milking frequency management in pasture-based automatic milking system: A review. Livest. Sci. 159:102-116.
  4. Lyons, N. A., K. L. Kerrisk, and S. C. Garcia. 2013. Comparison of 2 systems of pasture allocation on milking intervals and total daily milk yield of dairy cows in a pasture-based automatic milking system. J. Dairy Sci. 96:4494-4504.
  5. Lyons, N. A. 2013. Investigations on Variable Milking Intervals, Cow Performance and Grazing Behaviour in a Pasture-based Automatic Milking System. Ph.D. Thesis, Faculty of Veterinary Science, The University of Sydney, NSW, Australia.
  6. Nicol, A. M. and I. M. Brookes. 2007. The metabolisable energy requirements of grazing livestock. In 'Pasture and Supplements for Grazing Animals: Proceedings of the New Zealand Society of Animal Production 2007' (Eds. P. V. Rattray, I. M. Brookes, and A. M. Nicol). Occasional Publication No. 14, New Zealand. pp. 151-172.
  7. Ouweltjes, W. 1998. The relationship between milk yield and milking interval in dairy cows. Livest. Prod. Sci. 56:193-201.
  8. Ribiero, J. M. D. C. R., J. M. Brockway, and A. J. F. Webster. 1977. A note on the energy cost of walking in cattle. Anim. Prod. 25:107-110.
  9. Schutz, K., D. Davison, and L. Matthews. 2006. Do different levels of moderate feed deprivation in dairy cows affect feeding motivation? Appl. Anim. Behav. Sci. 101:253-263.
  10. Sejian, V., V. P. Maurya, and S. M. K. Naqvi. 2012. Effect of walking stress on growth, physiological adaptability and endocrine responses in Malpura ewes in a semi-arid tropical environment. Int. J. Biometeorol. 56:243-252.
  11. Stelwagen, K. and C. H. Knight. 1997. Effect of unilateral once or twice daily milking of cows on milk yield and udder characteristics in early and late lactation. J. Dairy Res. 64:487-494.
  12. Stockdale, C. R. 2006. Influence of milking frequency on the productivity of dairy cows. Aust. J. Exp. Agric. 46:965-974.
  13. Thomson, N. A. and M. L. Barnes. 1993. Effect of distance walked on dairy production and milk quality. Proc. NZ Soc. Anim. Prod. 53:69-72.
  14. Wilde, C. J., C. V. P. Addey, L. M. Boddy, and M. Peaker. 1995. Autocrine regulation of milk secretion by a protein in milk. Biochem. J. 305:51-58.
  15. CSIRO. 2007. Nutrient Requirements of Domesticated Ruminants. CSIRO Publishing, Collingwood ,VIC, Australia.
  16. D'hour, P., A. Hauwuy, J. B. Coulon, and J. P. Garel. 1994. Walking and dairy cattle performance. Ann. Zootech. (Paris) 43:369-378.
  17. di Marco, O. N., M. S. Aello, and D. G. Mendez. 1996. Energy expenditure of cattle grazing on pastures of low and high availability. Anim. Sci. 63:45-50.
  18. Erdman, R. A. and M. Varner. 1995. Fixed yield responses to increased milking frequency. J. Dairy Sci. 78:1199-1203.
  19. Farina, S. R., S. C. Garcia, and W. J. Fulkerson. 2011. A complementary forage system whole-farm study: Forage utilization and milk production. Anim. Prod. Sci. 51:460-470.
  20. Farina, S. R., A. Alford, S. C. Garcia, and W. J. Fulkerson. 2013. An integrated assessment of business risk for pasture-based dairy farm systems intensification. Agric. Syst. 115:10-20.
  21. Garcia, S. C. and W. J. Fulkerson. 2005. Opportunities for future Australian dairy systems: A review. Aust. J. Exp. Agric. 45:1041-1055.
  22. Garcia, S. C., W. J. Fulkerson, and S. U. Brookes. 2008. Dry matter production, nutritive value and efficiency of nutrient utilization of a complementary forage rotation compared to a grass pasture system. Grass Forage Sci. 63:284-300.
  23. Hammer, J. F., J. M. Morton, and K. L. Kerrisk. 2012. Quartermilking-, quarter-, udder- and lactation-level risk factors and indicators for clinical mastitis during lactation in pasture-fed dairy cows managed in an automatic milking system. Aust. Vet. J. 90:167-174.
  24. Holmes, C. W. and G. F. Wilson. 1982. Milk Production From Pasture. Butterworths, Wellington, NZ.
  25. Islam, M. R. and S. C. Garcia. 2012. Effects of sowing date and nitrogen fertilizer on forage yield, nitrogen- and water-use efficiency and nutritive value of an annual triple-crop complementary forage rotation. Grass Forage Sci. 67:96-110.
  26. Islam, M. R., S. C. Garcia, and K. L. Kerrisk. 2012. A modelling approach to screen grazeable forage options for automatic milking system herds. In: Proceedings of Australasian Dairy Science Symposium 2012 (Eds. J. Jacobs, S. C. Garcia, S. Little, D. Barber, G. Edwards, J. Roche, J. Jago, and D. Pacheco). National Dairy Alliance: Melbourne, Australia. pp. 459-460.
  27. Islam, M. R., S. C. Garcia, C. E. F. Clark, and K. L. Kerrisk. 2013a. System fitness of grazeable forages for large herds in automatic milking system. Proc. Int. Grassl. Congr. pp. 1717-1718.
  28. Islam, M. R., C. E. F. Clark, K. L. Kerrisk, S. C. Garcia, and N. A. Lyons. 2013b. Land areas required, associated walking distance and milking interval for large herds in pasture-based automatic milking system. Paper presented in Precision Dairy Conference, June 2013; Rochester, MN, USA.
  29. Islam, M. R., S. C. Garcia, C. E. F. Clark, and K. L. Kerrisk. 2015a. Modelling pasture-based automatic milking system herds: grazeable forage options. Asian Australas. J. Anim. Sci. 28:703-715.
  30. AFRC. 1993. Energy and Protein Requirements of Ruminants. An Advisory Manual Prepared by the AFRC Technical Committee on Responses to Nutrients. Compiled by G. Alderman, in collaboration with B. R. Cottrill. CAB International, Wallingford, UK.
  31. ARC. 1980. The Nutrient Requirements of Ruminant Livestock. Commonwealth Agricultural Bureaux, Slough, UK.
  32. ARC. 1984. The Nutrient Requirements of Livestock. Technical Review by an Agricultural Research Council Working Party. Commonwealth Agricultural Bureaux. p. 101.
  33. Brody, S. 1945. Bioenergetics and Growth. With Special Reference to the Efficiency Complex in Domestic Animals. Reinhold. New York.
  34. Chapman, D. F., S. N. Kenny, D. Beca, and I. R. Johnson. 2008a. Pasture and forage crop systems for non-irrigated dairy farms in southern Australia. 1. Physical production and economic performance. Agric. Syst. 97:108-125.
  35. Chapman, D. F., S. N. Kenny, D. Beca, and I. R. Johnson. 2008b. Pasture and forage crop systems for non-irrigated dairy farms in southern Australia. 2. Inter-annual variation in forage supply, and business risk. Agric. Syst. 97:126-138.
  36. Collier, R. J., L. L. Hemandez, and N. D. Horseman. 2012. Serotonin as a homeostatic regulator of lactation. Domest. Anim. Endocrinol. 43:161-170.
  37. Coulon, J. B., P. Pradel, T. Cochard, and B. Poutrel. 1998. Effect of extreme walking conditions for dairy cows on milk yield, chemical composition, and somatic cell count. J. Dairy Sci. 81:994-1003.