Date of Award


Document Type

Doctoral Thesis

Degree Name

Doctor of Philosophy


Biological Sciences

First Advisor

Dr Roy Sleator

Second Advisor

Dr Bernadette O'Brien


The successful integration of automatic milking (AM) and grazing has resulted in AM becoming a feasible alternative to conventional milking (CM) in pasture-based systems. The objective of this thesis was to establish (i) the social, environmental and economic effects of adopting AM technology and (ii) the factors affecting cow traffic, which once the AM is adopted, can also impact on the sustainability of AM. A theme across this thesis is the examination of AM in the context of a seasonal pasture-based milk production system. Electricity and water meters were installed on seven AM fanns. Milking and livestock/^miscellaneous processes were the largest consumers of electricity and water, respectively. Labour audits were conducted on seven and 10 AM and CM farms, respectively, and showed that there was a 36% reduction in labour with AM. A stochastic budgetary simulation model was used to establish the economic consequence of investing in an AM system relative to CM systems. AM technologies were less profitable than CM parlours of medium specification, but were as profitable as CM parlours of high specification. From a review of the literature knowledge gaps concerning (i) the effect of supplementation level and stage of lactation and (ii) suitability of breeds to AM were identified as areas pertinent to pasture-based systems. Low and high concentrate supplement levels were implemented. In late lactation, the high concentrate treatment had a greater milk yield, and a shorter milking interval and return time/visit. In a breed experiment, there were no differences between Holstein- Friesian, Jersey x Holstein-Friesian and Norwegian Red x Holstein-Friesian for milking frequency or milk production, although differences existed with regard to cow traffic. Greatest AM utilisation may be achieved by a mixed breed herd rather than a single breed herd, due to the complementary milking pattern that existed between the breeds.


Thesis completed in collaboration with Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland.

Access Level


Project Identifier

info:eu-repo/grantAgreement/EU/FP7/314879/IE/Innovative and sustainable systems combining automatic milking and precision grazing/AUTOGRASSMILK