Authors: H.J.C. van Dooren, E. Spörndly, H. Wiktorsson
As part of workpackage 10 (Automatic milking and grazing) within the EU project ‘Implications of the Introduction of Automatic Milking (AM) on Dairy Farms’, results of surveys conducted on farms which have experiences with grazing systems designed for their specific conditions have been summarised. The objective was to document the existing practices of grazing and management systems of cows in herds with automatic milking systems and identify strengths and weaknesses.
Information received through surveys in different EU countries revealed that grazing practices varied between 0 and 100 %. In Italy all the existing 15 herds milked automatically, practised zero-grazing both before and after introduction of automatic milking, while in Sweden the Farm Animal Ordinance stipulates pasturing 2 to 4 months per year. In Belgium, France and The Netherlands, at least restricted pasturing was practised on 71, 48 and 53 % of the AM herds, respectively.
The main results are collected from a comprehensive study of 25 Dutch farms. The study spotlighted factors that influence production, labour and number of milkings, such as: duration of pasturing, the supplementary feeding in the barn, the distance to the fields, the pasturing system and fetching the cows from the pasture, which focus on the different ways farmers succeed in combining automatic milking and grazing. The types of grazing systems in use among the farmers were continuous grazing, rotational grazing every two or three days, and strip grazing. Some farms used a two-field system in which cows started the day in one field, and those coming out of the barn later in the day went to another field. The distance between the barn and the field ranged from a few metres to 1300 metres. All the farms gave supplementary food, ranging from 2.5 to 15 kg DM per cow and day. The study revealed that 13 of the 25 farmers fetched their cows twice a day and 12 usually fetched cows once a day. The percentage of cows fetched varied from 0 to over 90%.
Three farmers from the group of 25 farmers taking part in the previous survey were selected for further research. For the past three years, each of these farms has been combining grazing with automatic milking in their own way. On all three farms the cows have adapted well to the grazing in combination with automatic milking. Cows need a relatively long time to get into a rhythm. But once cows know that they can only go to the pasture after milking, there is no restlessness in the barn if cows go to the pasture every now and then. This stimulates a dispersed pattern of returns to the barn, resulting in more regular milkings, which benefits both the cow and the milking capacity. For optimal use of the AM-system it is therefore important for dairy cows to get used to a pattern that is repeated daily and in which they do not get used to being fetched.
A smaller surveys of three farms has been performed in Sweden. As automatic milking was introduced later there, the farms in these studies had fairly recently changed to automatic milking. In the first year after introduction the proportion of times, animals had to be fetched seemed to be affected by the length of time that the animals had to get accustomed to the AM-system. Another important factor that probably affected the level of voluntary visits was the size and type of pasture area. During the second year a comparison between heifers and older cows (with at least 3 lactations) showed that the younger animals had approximately 0.1-0.2 more milkings per day compared with older cows at the same production level. During the second grazing season also cow behaviour was studied to see how much time the animals spent outdoors and how much time they spent grazing. Cows had a diurnal rhythm, spending more time outdoors and grazing in the afternoons and evenings and more time indoors in the late night–early mornings. A more pronounced diurnal rhythm in going to the milking unit was also observed during the grazing season.
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© Animal Sciences Group -
Wageningen UR. Last update:
20-02-2008 10:03. |
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