Authors: E. Spörndly, E. Wredle
In automatic milking systems, cows go voluntarily to the milking unit several times per day to be milked. During the grazing season, when the cows are out on pasture, the distance between the cow and the milking unit is much longer than during the indoor period and the pasture offers a high quality feed in the immediate vicinity of the cow. Therefore it may be difficult to motivate the cow to leave the pasture and walk to the milking unit several times per day to be milked. This project places focus on cow motivation to visit the milking unit during the pasture season. It is part of work package 10, Automatic milking and grazing, in the EU project “Implications of the introduction of automatic milking on dairy farms” and has been financed both by the EU and the Swedish Farmers’ Foundation for Research.
This report presents the results of a number of experiments where different factors that affect milking frequency have been studied. Although some basic experiments have been performed indoors, focus has been on the pasture season and the grazing situation. Factors of importance to milking frequency that are discussed in this report are feed related factors, water supply, environmental factors and cow locomotion. The report also presents results from experiments studying the learning process of cattle with the objective to teach the animals to respond to an individual auditory signal. A cow-calling apparatus has also been tested during the pasture season to summon the individual cow to the milking unit.
The effect of different amounts of supplementary roughage, offered in the barn, on milking frequency was studied in two experiments. In both these experiments an ad libitum supplementation of roughage or mix offered indoors during the pasture season did not increase cow motivation to visit the milking unit compared with a lower level of supplementation (4 kg dry matter). In another experiment, the system of feed supply was studied, comparing free and semi-forced cow traffic during the pasture season. Cows with semi-forced cow traffic had a significantly higher voluntary milking frequency compared with cows that had free cow traffic, 2.4 and 1.8 milkings/cow and day, respectively, as an average over three sub-periods at pasture.
The effect of the distance between the pasture and barn was studied in an experiment that lasted a whole grazing season. The results showed that during the first half of the grazing season, cows with a shorter distance to the barn had a significantly higher milking frequency compared with cows that had a longer distance, 2.5 and 2.3 milkings/cow and day in the two groups, respectively. In another experiment cows with water only in the barn had a milking frequency that was slightly higher compared with cows that had drinking water both at pasture and indoors, but the difference was significant only during a pasture period when the cows grazed at a longer distance from the barn (260 meters).
Variables that describe cow locomotion were studied in an overall analysis. Locomotion variables gave a significant contribution to explaining the variation in voluntary milking frequency during both the pasture and indoor period when step-wise analysis was performed.
In an experiment, heifers were trained to approach a feed resource in response to an auditory signal using shaping or classical conditioning. The results were successful with regard to shaping, where eight out of ten heifers learnt to approach the feed resource when the signal was given. In the summer, auditory signals were used in a cow-calling experiment in an AM-system. Cows were trained to approach the milking unit in response to an auditory signal. Later they were given the signal as a stimulus to motivate the cows to go to the milking unit for milking. Preliminary results showed that no consistent response was obtained on a group basis. However, a more detailed analysis of the individual results still remains to be done.
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Wageningen UR. Last update:
20-02-2008 10:03. |
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