Open access publications in the SLU publication database

Investments in large-scale milk production and new technical solutions implemented in recent year’s implies great changes in the working conditions of the farmers and workers on dairy farms. The work pace and number of working hours for individual work operations, such as milking, tend to increase. This process of change has likely resulted in a change of work patterns and exposure to various risk factors, which require profound knowledge in order to develop effective strategies for preventive measures and intervention in the work environment of the milkers.
It is well known from national and international studies that those engaged in dairy farming has a high frequency of musculoskeletal problems (MSD) with aches, pains and discomfort in different body regions which can lead to disability, reduced work ability and increased risk of injuries and accidents. It is important to identify and quantify the level of work load in different milking system in order to be able to give recommendations regarding technical solutions and working techniques that can prevent the development of MSD in milkers.
The aim of the present study was to quantify the physical work load when milking in parallel and herringbone milking systems in order to provide recommendations on ergonomic solutions and appropriate working technique.
Field studies were conducted at four large dairy farms in Sweden with different milking systems setups: Herringbone system, where the cows are milked diagonally from the side; Rotary herringbone system where the cows are standing on a rotating platform and milked diagonally from the side while the milker stands still; Parallel system where the cows are milked from behind and Rotary parallel setup where the cows are standing on a rotating platform and milked diagonally from the side while the milker stands still.
The milkers were videotaped while working in the different milking setup to record the working postures and movements. The design of the various systems, the weight of the milking equipment, the farmers' working heights, working distance and distance from the floor where the cows were standing to cow udder were measured on the farms.
Interviews with the milkers were carried out in relation to musculoskeletal disorders and perception of physical strain during milking in the various systems. The biomechanical analysis software ALBA was used to quantify the physical work load on different joints in the various milking systems.
Tall men who were forced to bend their back to reach the front teats of the cow had maximum work load regardless of the milking system. The work load on the arm/shoulder holding the milking cluster was about 60% higher compared to the arm without the burden of a cluster. The load on the lower back (L5/S1) was about 10% higher during milking compared with drying the teats and udders at premilking.
The calculations showed no difference between the various milking setups concerning the work load on different body joints of acceptable postures meaning where the milker was not forced to stand on tiptoe or bend their back to reach the front teats of the cow. Differences of importance for the load were, however, in solutions within the different milking setups and in the variation of high and low placed cow udders in combination with different heights of the milkers. Technical means to facilitate the work such adjustable floor, support arms, indexing of the cows and lightweight milking clusters can partly compensate for this variation.
The high frequency of musculoskeletal disorders of the milkers is not only initiated by the design of the milking systems, anthropometrics (measurement of the size and proportions of the human body) and bovimetrics (measurement of the size and proportions of the cow body). Other contributing factors may be long working hours, monotonous and repetitive work tasks, psychosocial and organizational factors. Good working techniques such as working close to your body, using both hands, or switch hands and avoid working in extreme positions of the joints is also important to keep in mind to avoid MSD.