Optimizing grazing in dairy herds with automatic milking systems

The project is motivated by recent years' major changes in milk production, as a result of technological changes and changes in regulations governing the Norwegian dairy production. The main features of this development is the introduction of automatic milking systems (AMS), increasing herd sizes, requirements for cubicle housing for all cows from 2034 and demand for pasture in 2014. Grazing, and grazing in combination with AMS in particular, may however offer some challenges. There is a clear trend worldwide in reduced use of grazing in larger herds, and in particular in herds with AMS. Recognizing an acute need in finding management practices easing the use of grazing and reducing or resolving the negative impacts of grazing on AMS-farms, the GRAZELAND-project has scrutinized some seemingly well-established views regarding grazing, and tested out various management tools aiming to work around some of the constraints to grazing that are of greater economical impact. Three controlled studies are included in the project, all conducted at the Swedish University of Agricultural Sciences in Uppsala. The first two (where one was a method study made within the frames of the main trial) were conducted summer 2015. The third trial ran summer and autumn 2016. The production and behaviour of cows with two different pasture allowances in two different part-time grazing schemes were compared. Results from the main trial of 2015 and the 2016 trial are published in scientific journals (Livestock science, Journal of Dairy Science). Preliminary results have also been presented at conferences, in several popular scientific presentations and daily press. The main findings of these studies are that we could detect no systematic difference in how well cows produced depending on what kind of outdoor access they had. However, cows with access to pasture spent more time outdoors than cows with access to a grass-covered paddock ? also if disregarding time spent foraging. In situations where, for whatever reasons, outdoor access need to be restricted to only parts of the day, our data indicate that offering outdoor access in the morning and then again in the afternoon and evening better suits the preference of the animals. For the method study we capitalized on having two animal groups where we had a known total feed intake registered for the one group, and for the other a known feed intake indoors and an unknown pasture intake. This was used to search for cheap and feasible methods to estimate pasture intake in real time, which could be a useful tool in feed management on commercial farms, and/or in research settings where more advanced methods are not feasible due to limited resources. The results from this study are awaiting publication in a scientific journal. Preliminary results have been presented at various conferences. The main finding is that use of urine spot sampling could in a research setting be an economically viable alternative to more advanced feed intake estimates, although this method would not be suitable for use on a commercial farm. However, measuring drinking water intake as way to estimate feed intake may perhaps be useful for feeding management on group level in the future, but we are not there quite yet. The field study is based on a questionnaire survey sent all Norwegian dairy farmers. It was developed in collaboration with national and international partners, and with great contributions from a workshop with representatives of most stakeholders. The survey was paired with respondent farms' registry data. Changes in production and health indicators as a response to pasture turnout was estimated on farm- and individual cow-level. Herds with and without AMS were then compared on basis of the trend of these responses. The most important findings in this field study so far is that we can find no evidence supporting a cause-and-effect relationship between either milking system and response to pasture turnout or outdoor access solution and response to pasture turnout, as variance is greater within the groups than between them. The difference in success or failure different farms experience with grazing is thus most probably due to other, or the sum of several, differences in on-farm conditions. An own report on the economy in grazing in AMS-herds is published as part of the project. This is based on both Norwegian and Swedish conditions, and is also included as a part of deliveries on the Swedish side of the project. Data from the project have contributed to several student works - two Swedish masters thesis, three Norwegian bachelor thesis, and two summer-internships from the Netherlands and France.

Prosjektet har vist at det er mulig å opprettholde melkeytelsen i et produksjonsopplegg som kombinerer automatisk melking og beiting. Dette er en viktig kunnskap i og med at mange synes å ha en oppfatning av at dette ikke lar seg gjøre. Beiting representerer økt dyrevelferd i form av mosjon og naturlig atferd, og på den måten kan resultatene fra prosjektet potensielt ha betydning for dyrevelferden. Videre er beiting viktig i kulturlandskapet og sannsynligvis også i klimasammenheng. Metodikken som er utviklet vil kunne ha en verdi også for videre forskning. Prosjektsamarbeidet mellom Norge og Sverige har vært fruktbart, og med samarbeidet i dette prosjektet som basis, har Nord universitet og Sveriges Lantbruksuniversitet (SLU) inngått en gjensidig avtale om studentutveksling. Prosjektet har også banet vei for videre samarbeid mellom institusjonene, og for Nord universitet har det vært en døråpner for et internasjonalt fagmiljø som forsker på spørsmål relatert til beiting.

The proposed project is motivated by the major changes in milk production in recent years. This is a result of technological changes and changes in regulations governing the Norwegian dairy production. The main features of this development is the introduc tion of automatic milking, increasing herd sizes, requirements for loose housing for all cows from 2024 and demand for pasture in 2014. Grazing in combination with automatic milking systems (AMS) provides some challenges that this project will focus on th rough two work packages which should be performed a controlled study and a field study. The controlled study planned to take place at the Swedish University of Agricultural Sciences (SLU) in Uppsala. We will, through a 6-week long trials seek to find ans wers to how different number of hours per day with access to pasture, different animal density and allocation times for supplemental impacts milk performance, number of milking per day, forage uptake and utilization of pasture. The field study is based o n the collection of production data from the Norwegian AMS barns combined with a survey of grazing practices, cow flow, working time consumption and more. Production data is downloaded directly from the milking robots. Data obtained from these two work pa ckages will be systematized, processed and analyzed. Publication of the findings will be in the form of peer reviewed papers in international scientific journals combined with popular scientific articles and contributions at national and international c onferences and professional meetings.