Productivity in Swedish pig production is high, but unfortunately so are production costs, especially those of labour and of buildings. The piglet producing herds allocate about a quarter of their total working time for the work operation scraping manure (including supervision). In addition to being labour consuming, the workers also consider that manure scraping is heavy and hard work. Problems with musculoskeletal disorders (MSD), especially in the upper extremities, are also a reality for today's workers in animal production, especially for women. Since women mainly work in the farrowing and lactation units in Swedish pig herds, farrowing pen design deserves special attention. In this study, working time and workload for two different work operations in the farrowing unit, was studied in 16 herds. The purpose was to obtain more knowledge about the workload of workers in modern farrowing pens and to use this knowledge to develop recommendations to prevent injuries among the workers. The herds were visited on 1-2 occasions per herd. One of the herd selection criteria was that the herds had farrowing pens which were built after year 2000. There were 7 herds with pens for farrowing, lactation and nursery (until 25 kg) periods (pen type A, without a protective gate system) and 9 herds with pens for farrowing and lactation (pen type B, with protective gate system). In the present study, previously conducted observations were supplemented with details about the gate structures, closures, piglet corners, gaps to remove manure etc. Two working operations, "Removal of manure and monitoring the animals “(WO1), where manure scraping and control of the piglets were combined, and "Handling of piglets” (WO2), where the time required to capture and mark all piglets in the pen with a colour marker on zthe back, were studied. The working operations were carried out continuously in a number of farrowing pens per unit. The time spent on the various work elements within the work operation was registered using a portable handheld computer (PSION). Both work operations were performed by the same person in all herds (person 1). Similarly, all the work time registrations using the hand computer were carried out by the same individual (person 2) in all the herds. The following work elements were recorded: transport outside the pen, transport inside the pen, work with pen gates, manure scraping from inside the pen, manure scraping from outside the pen, work with boards, work with creep area, work with handling of the pigs (catching each pig, lifting them up, marking them on the back with a colour marker). Using a digital camera, the different work elements in the two working procedures were videotaped. Observation studies of the video recordings were used to carry out detailed analyses of the workload and to visualize and identify the movements and postures used in the studied work procedures. To analyze the work postures in the different work lements, the program WinOWAS was used. WinOWAS is based on 84 so-called “basic type work positions” after evaluations of the positions of the back (4 positions), the arms (3 positions)and the legs (7 positions). The various “basic type work positions” are, depending on the degree of work load, classified in one of four action categories (higher score corresponding to higher load). For the various work elements, the program calculated the percentage of time in each action category. Classification of load was also made for the weight of the burden that was handled ( 20 kg) (Figure 1). To calculate the load on the different body parts, the program 2DSSPP (2D Static Strength Prediction Program) was used. The study estimated the torque (Nm) as a measure of the mechanical stress on the shoulder and lumbar spine (Figures 2 and 3) for the work elements: “Manure Scraping (keeper inside the pen)" and "Manure Scraping (keeper outside the pen)". The load of the work element "Manure Scraping (keeper outside the pen)" was calculated when reaching with the scraper either 150 cm or 200 cm. The study showed that there was a wide variation in the farrowing pen designs. In addition to variation in size, many different solutions for equipment details were found. How well the solutions functioned would have significant impact on the work time and work load for the different work elements. For example, the design of the gate locking system (Figure 4) affected how quickly the opening and closing of the gates could be done. In some of the farrowing pens, retractable wooden boards were used instead of gates (Figure 5). In these pens, the keeper normally stepped over the wall when entering the pens during the daily manure scraping routine. From a work load perspective, it would be a disadvantage to have to climb over a wall instead of being able to walk through a gate. In some pens, the gates in the dung alley between the pens were designed with a low "threshold", so that the keepers had to deal with both a gate and climbing over a low wall (Figure 6). The time spent manure scraping was not only affected by the pen hygiene but also how the manure was scraped into the manure channel (Figure 7). Having flaps in the slatted floor often were perceived as a problem because they often were not sufficiently durable. Openings in the slats under the gate between the pens in the manure channel appeared to be the most valued solution. In many of the herds manure scraping was not done in the whole pen every day. On certain week days, only the concrete area in the pen was cleaned and the manure moved out onto the slatted area. The actual manure scraping work was most often carried out from inside the pen but sometimes it was done from the inspection alley (Figure 8). In order to be able to scrape from the inspection alley, the pen had to be “facing forward” i.e., the solid floor had to be placed adjacent to the inspection alley and the slatted floor had to be relatively large so that the solid area did not become too wide. For the work operation “Handling of piglets” the capturing of the piglets was facilitated if the pigs could be gathered in a piglet corner. Most of the type A pens were equipped with a permanent board which could be closed to lock in the piglets. In pen type B such permanent “closing in” devices for the piglets were missing. Instead, loose boards, which were moved from pen to pen, were hooked onto metal profiles on the pen wall. The average time for the work operation WO1 "Removal of manure and monitoring the animals“, was a little longer (0.95 min) in the type A-pens (no protective gate system and 64% solid floor), than in the type B-pens (0.76 min) (with a protective gate system and 52% solid floor). However, the difference between the pen types was not statistically significant (Table 1). Type A-pens were scraped predominantly from inside the pen (98% of the cases), while type B-pens more often were scraped from the inspection alley (55% of the cases). The mean time for “Handling of piglets” (WO2) was slightly shorter in type A-pens (1.38 min) without protection devices, compared with the type B-pens (1.50 min) with a protective gate system. The difference was not significant (Table 1). Work with pen manure scraping from inside resulted in a work load score of 1.50, as compared to that of 1.83 when the pen scraping was done from the inspection alley, because particularly the spine is subjected to greater stress when the pen manure is scraped from outside. Capturing and colour marking the pigs involved both bending and twisting the back, and this work element was therefore the most stressful one in the work operation WO2, with a work load score of 2.65 (Table 3). In Figure 10 it is shown that, for WO1, a shorter working time often has to be "paid for" by a higher work load. Despite a numerically longer working time (although not significant) for WO1 in pen type A, a significantly lower work load for this work operation (WO1) and pen type was registered, as compared to that for the type B-pen (Table 3). The relationship between working time and work load for WO2 was reversed. A tendency towards a shorter working time for WO2 in the type A-pens resulted in there being a tendency to a higher work load in this pen type (Table 4, Figure 11). The mechanical load on the shoulders and back was alculated for the work element "manure scraping" when the keeper either carried out the work from inside the pen or from the outside (Figure 12). When scraping pen manure from outside, the work load according to two different depths (150 and 200 cm) of how far the keeper had to reach as a maximum, was compared. Maximum work load on both the shoulders and the back was obtained when the keeper had to scrape pen manure from outside, extending to a maximum of 200 cm (Table 5). Farrowing pens with partly solid floors will always require a certain work time for manure scraping. As expected, the study showed that the work time for “removal of manure and monitoring the animals” (WO1) was longer (0.95 min per pen) in type A-pens, with a higher proportion (64%) of solid pen flooring compared with the type B pens (0.76 min per pen), with a smaller proportion (52%) of solid flooring. However, the variation between the different herds was large, and the difference was not significant. The results suggested that it was not only the relationship between the solid and the slatted areas in the pen that affected the pen manure scraping working time. In type B-pens, it was possible to reach and scrape the solid floor from the inspection alley outside the pen. This was because the solid floor was not as wide/deep as in pen type A. Thus, no working time for opening gates was needed. However, in the studies of work load, it was concluded that it was more stressful to scrape pen manure from outside (score 1.83), compared with inside the pen (score 1.50). To scrape pen manure from outside meant more bending and more twisting of the back, compared to carrying out this work element inside the pen. The biomechanical calculations showed that it could be up to four times more burdensome, especially for the back, to scrape pen manure from outside than inside. The work load depended on how far into the pen the keeper needed to reach with the scraper. The height of the pen wall and the location of the solid pen area in relation to the inspection alley were other factors affecting this work load. The results were interesting and should provide ground for reflection among the people in managerial positions in our pig producing herds. Together with an achievable positive and wanted rationalization of the work with manure scraping in the newer farrowing pens, the work with scraping has actually become more of a burden for the keepers. Given that reports of MSDs problems already are many, the result was somewhat alarming. In conclusion, the "new" Swedish farrowing pens appear to be more competitive in terms of working time for the work element “manure scraping”, but the work with manure scraping that remains becomes more of a burden. For the employees, this does not directly mean something positive. Instead, the overall work load increases at the same time as an employee manages to clean a larger number of farrowing pens. This condition means that the requirements for a good and well planned work organization in future pig-producing herds, so that the staff do not risk injuries in the future, will be even higher. It is suggested that the modern, large-scale agriculture make use of the experience gained in other industries. Job rotation and alternation between work tasks is recommended as being important components of future organization on pig farms to reduce occupational injuries among the pig keepers
