Acceptance and Feasibility of a Guideline for the Animal Welfare Assessment of Fattening Pigs from Farmers’ Point of View

The welfare of farm animals is being increasingly discussed in society and politics. To evaluate animal welfare, indicator systems are often used. Such a system has been developed by the German Association for Technology and Structures in Agriculture and suggested in the publication “Animal Welfare Indicators: Practical Guide—Pigs”. The association’s aim is to provide farmers with a useful method for recording the welfare of pigs. Crucial for the acceptance of the guide by farmers is a high degree of feasibility of the recommended indicators as well as the proposed methods for their recording. To evaluate this, 40 farmers keeping fattening pigs were interviewed. The guided semi-structured interview was conducted on the farms after the farmers evaluated the welfare of their fattening pigs according to the guide. The results are: Apart from the indicators faecal soiling and tail length, all the other eleven indicators are accepted for the assessment of fattening pig welfare by a majority of the interviewed farmers (between 57.5% and 90% acceptance per indicator). Furthermore, the feasibility of the individual indicators was assessed as being positive. The relationship between time expenditure and benefit was rated on a five-point scale at an average of 3.1 (medium), which clearly shows that there is a need for further development of this guide. Some possible changes with a potential for improvement could be identified; for example, the aggregation of the results after the collection of the individual indicators to an overall result that can be compared and interpreted

Range measurements of a High Frequency Radio Frequency Identification (HF RFID) system for registering feeding patterns of growing-finishing pigs

Monitoring the feeding pattern of a pig enables early detection of diseases and other problems. To monitor the individual feeding pattern of group-housed pigs, it has been suggested to equip the pigs with High Frequency Radio Frequency Identification (HF RFID) tags and the feeding trough with an antenna. The detection range of the HF RFID system is crucial to guarantee that all feeding pigs are detected without detecting the pigs located further from the feeder. The current study examines the factors that influence whether an antenna attached to a round feeding trough (such as those used in group housing of growing–finishing pigs) detects stationary HF RFID tags placed in various orientations and distances from the antenna. Four experiments were performed using a custom-built test set-up that allowed determining the RFID registrations for 70 tag positions, at seven distances from the antenna and for seven orientations of the tags in relation to the antenna. In the first experiment there was determined that which tag side is closest to the antenna had very little influence on the range of registration. The results of the second experiment revealed that all eight HF RFID antennas in the pig house performed similarly, with symmetry observed in their range of registration. In the third experiment the range of the HF RFID system was measured while accounting for tag, tag position and tag orientation, whilst the last experiment was designed to test the effect of interference between tags. Reproducibility between (the order of) the tags and the average agreement between five repetitions of all tests was very high. In total, the sensitivity was 51.0%, with a standard deviation of 43.1percentage point (pp). The specificity was 87.1% with a standard deviation of 19.4pp. It was concluded that the performance of the HF RFID system in terms of sensitivity and specificity of the range depends greatly on the height and orientation of the tags. This causes irregular gaps to appear between subsequent RFID registrations of a feeding pig. To improve the performance of the system in practice, it is suggested to adjust the height of the antenna to better match the size of the pigs and to develop algorithms and criteria to merge raw RFID registrations into relevant feeding variables for individual pigs.publisher: Elsevier articletitle: Range measurements of a High Frequency Radio Frequency Identification (HF RFID) system for registering feeding patterns of growing–finishing pigs journaltitle: Computers and Electronics in Agriculture articlelink: http://dx.doi.org/10.1016/j.compag.2014.08.006 content_type: article copyright: Copyright © 2014 Elsevier B.V. All rights reserved.status: publishe

Validation of a High Frequency Radio Frequency Identification (HF RFID) system for registering feeding patterns of growing-finishing pigs

Automated monitoring of the feeding patterns of growing-finishing pigs would allow detecting problems with individual pigs or groups of pigs and thus improving health, welfare and productivity of the farm. In this paper a High Frequency Radio Frequency Identification (HF RFID) system was validated for its suitability to register individual pigs’ feeding patterns at a round trough in a group-housing context. High Frequency RFID antennas were installed above the troughs of a commercially available type of round feeder to identify feeding pigs fitted with one or two passive RFID tags on their ears. A multiplexer was used to connect multiple antennas to a single reader. During 11.5h, video observations of 20 focal pigs (equipped with two tags) at an age of 16weeks were performed to validate the system. A large variation in feeding patterns of the 20 focal pigs was found. Correlation between the number of registrations per pig and the feeding duration on video was low (R2=0.53) mainly due to four pigs with specific feeding behaviour (with the four pigs excluded: R2=0.88). The RFID registrations of the 20 focal pigs – with irregular time gaps between them – were compared with instantaneous video samples using several time window sizes around the video sample. The specificity for individual pigs with one or two tags was always above 85%, but sensitivity varied for individual pigs, tags and with different time windows used. A quantitative comparison between the use of one or two tags per pig was made based on a receiver operating characteristic (ROC) curve. For two tags per pig a sensitivity of 88.58% and a specificity of 98.34% can be reached with a time window size of 9s. For one tag per pig, sensitivity is only above 85% at a time window of size 31s. Of the total number of RFID registrations 77.11% occurred during feeding visits, and 92.23% occurred during or within 10s of feeding visits on video. This system showed good potential for measuring feeding patterns of growing-finishing pigs in commercial pig houses, for research purposes, or to detect potential problems with pigs by signalling changes in the registered feeding patterns.publisher: Elsevier articletitle: Validation of a High Frequency Radio Frequency Identification (HF RFID) system for registering feeding patterns of growing-finishing pigs journaltitle: Computers and Electronics in Agriculture articlelink: http://dx.doi.org/10.1016/j.compag.2013.12.015 content_type: article copyright: Copyright © 2014 Elsevier B.V. All rights reserved.status: publishe

Methods to construct feeding visits from RFID registrations of growing-finishing pigs at the feed trough

Changes in the feeding pattern of a pig may indicate disease or welfare issues and can also be strongly related to productivity changes. Automatic measurements of the feeding patterns of group-housed growing-finishing pigs can enable the detection of such feeding related changes. In this paper, a high frequency (HF) Radio Frequency Identification (RFID) system was used to register pigs’ feeding patterns at a commercial-type feed trough. The raw RFID registrations had to be translated into feeding visits, as there were irregular time gaps between the registrations that were inherent to the system for this application. Data from two experiments were used: one used behavioural observations of six pigs during three days with the aim of finding the best method for visit construction (experiment 2, E2), whilst the other experiment used feeding pattern observations of 20 pigs on one day as an independent validation data-set (experiment 1, E1). Three methods for visit construction were proposed: (1) visit criteria (a bout criterion and a minimum duration criterion), (2) a digital filter (using a well-defined time delay and a threshold for feeding) and (3) erosion and dilation operations from mathematical morphology. The best results were obtained using a bout criterion equal to 10 s for two RFID tags per pig or 20 s for one RFID tag per pig. Removal of short visits was found to be unnecessary. This optimal method is equal to a closing operation (a dilation followed by an erosion). For the RFID system with the optimal bout criterion, using two tags per pig, average sensitivity was 83%, specificity 98%, accuracy 97% and precision was 75% for E2. Applying the same bout criterion on the independent test set (E1), resulted in an average sensitivity of 80%, a specificity of 99%, an accuracy of 98% and a precision of 78%. Performance of the method tended to be lower when using one tag per pig. Regression analysis revealed that the observed feeding duration was well-correlated with RFID-based feeding duration (R2 = 0.86 for two tags per pig, E1 + E2). Other observed variables (number of feeding visits and inter-visit interval) were harder to predict by the RFID system. From these results, there was concluded that feeding patterns can be recorded accurately in an automatic way if the registrations from the RFID system are analysed using an appropriate bout criterion.publisher: Elsevier articletitle: Methods to construct feeding visits from RFID registrations of growing-finishing pigs at the feed trough journaltitle: Computers and Electronics in Agriculture articlelink: http://dx.doi.org/10.1016/j.compag.2016.08.010 content_type: article copyright: © 2016 Elsevier B.V. All rights reserved.status: publishe