Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2015 The use of an embedded microcomputer-based force plate system for accurate sow lameness identification Brady Michael McNeil Iowa State University Follow this and additional works at:https://lib.dr.iastate.edu/etd Part of theAgriculture Commons,Animal Sciences Commons, and theVeterinary Medicine Commons Recommended Citation McNeil, Brady Michael, "The use of an embedded microcomputer-based force plate system for accurate sow lameness identification" (2015).Graduate Theses and Dissertations. 14622. https://lib.dr.iastate.edu/etd/14622 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please [email protected]. 1 ` The use of an embedded microcomputer-based force plate system for accurate sow lameness identification by Brady Michael McNeil A thesis submitted to the graduate faculty in partial fulfillment of the requirements of the degree of MASTER OF SCIENCE Major: Animal Breeding and Genetics Program of Study Committee: Kenneth Stalder, Major Professor Tom Baas Jarad Niemi Iowa State University Ames, Iowa 2015 Copyright© Brady Michael McNeil, 2015. All rights reserved. ii TABLE OF CONTENTS LIST OF TABLES........................................................................................................................v LIST OF FIGURES......................................................................................................................vi ACKNOWLEDGEMENTS........................................................................................................vii ABSTRACT .................................................................................................................................... i CHAPTER 1: GENERAL INTRODUCTION ........................................................................... 1 Thesis Organization ........................................................................................................................ 2 Expected Outcomes ........................................................................................................................ 3 Practical Implications...................................................................................................................... 4 Author Contributions ...................................................................................................................... 4 CHAPTER 2: LITERATURE REVIEW ................................................................................... 6 I. Group sow housing .................................................................................................................. 6 a. Productivity ............................................................................................................................. 6 b. Aggression ............................................................................................................................... 7 II. Sow lameness .......................................................................................................................... 8 a. Definition ................................................................................................................................. 8 b. Importance ............................................................................................................................... 9 c. Production impact .................................................................................................................. 10 III. Sow longevity .................................................................................................................... 10 IV. Causes of sow lameness ..................................................................................................... 11 iii a. Leg Conformation.................................................................................................................. 11 b. Foot problems ........................................................................................................................ 12 c. Nutrition................................................................................................................................. 13 V. Risk Factors of lameness ....................................................................................................... 15 VI. Methods of lameness scoring ............................................................................................. 17 a. Visual lameness scoring ........................................................................................................ 17 b. Mechanical lameness scoring ................................................................................................ 18 b.1 Force Plate lameness analysis .............................................................................................. 19 VII. Lameness classification tree .............................................................................................. 20 REFERENCES ............................................................................................................................. 21 CHAPTER 3: DETERMINING THE MINIMUM TIME REQUIRED TO DETECT SOW LAMENESS USING AN EMBEDDED MICROCOMPUTER-BASED FORCE PLATE SYSTEM ..........................................................................................................33 Abstract ......................................................................................................................................... 34 Introduction ................................................................................................................................... 35 Materials and Methods .................................................................................................................. 36 Cumulative Model ......................................................................................................................... 38 Minute Model ................................................................................................................................ 39 Test Minute Model ........................................................................................................................ 39 Test Cumulative Model ................................................................................................................. 39 iv Results and Discussion ................................................................................................................. 40 Conclusion .................................................................................................................................... 43 Acknowledgements ....................................................................................................................... 43 REFERENCES ............................................................................................................................. 44 CHAPTER 4: DEVELOPMENT OF A SOW LAMENESS CLASSIFICATION TREE USING AN EMBEDDED MICROCOMPUTER-BASED FORCE PLATE IN A COMMERCIAL SETTING ....................................................................................................52 Abstract ......................................................................................................................................... 53 Introduction ................................................................................................................................... 54 Materials and Methods .................................................................................................................. 56 Statistical analysis ......................................................................................................................... 57 Lameness classification tree ......................................................................................................... 57 Comparison between lameness evaluation systems ...................................................................... 59 Day of first lameness detection ..................................................................................................... 59 Results ........................................................................................................................................... 60 Discussion ..................................................................................................................................... 61 Conclusion .................................................................................................................................... 63 Acknowledgements ....................................................................................................................... 64 REFERENCES ............................................................................................................................. 65 CHAPTER 5: GENERAL DISCUSSION AND CONCLUSIONS ........................................ 73 v LIST OF TABLES Table 3. 1. Number of statistical weight distribution differences (P < 0.05) for each time period compared to the corresponding 10 minute interval with the Test Cumulative Model .............................................................................................................................................47 Table 3. 2. Least square means for the weight applied to each leg by injection site and time recorded on Day -1 and +1 relative to lameness induction in multiparous sows. .................48 Table 3. 3. The standard deviation for least square means for the weight applied to each leg by injection site and time recorded on Day -1 and +1 relative to lameness induction in multiparous sows. ..........................................................................................................................49 vi LIST OF FIGURES Figure 3.1. Pressure applied to each foot per minute on Day -1 using an embedded microcomputer-based force plate when the rear right foot was injected with 10 mg/mL amphotericin B in their distal interphalangeal joint, using the Minute Model. .............................50 Figure 3.2. Pressure applied to each foot per minute on Day +1 using an embedded microcomputer-based force plate when the rear right foot was injected with 10 mg/mL amphotericin B in their distal interphalangeal joint using the Minute Model. ..............................51 Figure 4. 1. Force applied1 to each foot2 per second3 for a sound sow using an embedded microcomputer-based force plate. ..................................................................................................69 Figure 4. 2. Force applied1 to each foot2 per second3 for a lame sow using an embedded microcomputer-based force plate. ..................................................................................................70 Figure 4. 3. Lameness classification tree. .................................................................................... 72 vii ACKNOWLEDGEMENTS I would like to acknowledge the National Pork Board, Iowa Pork Producers and Iowa Livestock Health Advisory Council for their financial assistance with these projects. I would like to thank my major professor, Dr. Kenneth Stalder. He has provided much mentorship and guidance on the workings of the swine industry and allowed me to explore many additional opportunities outside of my research and class requirements to expand my knowledge base. I have been truly lucky to have him as my major professor and am grateful for all the effort he has put into preparing me for the real world. Additionally, committee members, Dr. Tom Baas and Dr. Jarad Niemi, have been valuable in assisting in the satisfactory completion of my thesis through comments and suggestions. Thank you to the Animal Science Teaching program, specifically to Dr. Jodi Sterle, for awarding me an assistantship and providing me many developmental opportunities. As well as Dr. Baas, Dr. Stalder, Dr. Johnson, Mrs. Jennings and Ms. Jackson for their encouragement and guidance in education. I am especially thankful for all the help and thought provoking discussion provided to me by my lab mates, Dr. Caitlyn Abell, Dr. Julia Calderón Díaz, Joe Stock, Denise Beam, Amber Danielson, Muhammed Walugembe, Shoki Hirano, and Jared Mumm. I could not be where I am without the support of my family. Thank you to my parents Mike and Jean McNeil for shaping me into who I am today and my brother Alan James McNeil for always keeping me in-line. Lastly, I would like to thank, my fiancée, Katy Sartwell for sticking by my side and encouraging me during my schooling. viii ABSTRACT The objectives of this thesis were: i) to determine the minimum time required to record data from each individual load cell in the force plate system in order to obtain accurate sow weight distributions on each leg to objectively detect lameness, and ii) to develop a lameness detection decision tree from the force plate output collected in a commercial setting. In the first study, lameness was induced in 12 multiparous sows using a chemical synovitis model. Weight applied to each foot was recorded twice per second for 15 min on days -1, +1, +6, and +10 relative to lameness induction. Results suggest that there could be potential data collection problems after 12 min; therefore, 10 min was considered the maximum time required for weight recordings. Utilizing a 30 sec burn-in period to allow sows to become acquainted with the force plate, 30 to 210 sec was the time period that had the best combination of different readings and speed of collection compared to 30 to 630 sec. In the second study, one force plate was installed under an electronic sow feeder (ESF) in a dynamic group sow housing system with 120 multiparous sows for 21 days. Force applied by each foot was recorded once per second after the sow stood squarely on the plate and applied pressure to all quadrants during her first daily visit to the ESF. Sows were visually lameness scored using a four-point scale on a weekly basis. A decision tree was created using the variables that were deemed as more important for accurate lameness detection. The classification tree was 96% similar to weekly visual lameness identification. When comparing the output from the daily classification tree to a weekly visual lameness assessment, the force plate was able to identify lameness almost 5 days before it was visually assessed. Results from this thesis can be used to improve the embedded microcomputer-based force plate use efficiency when evaluating sow lameness and could help to identify lameness before clinical signs become evident. 1 CHAPTER 1: GENERAL INTRODUCTION Group sow housing is becoming more common in both the United States and abroad because of its benefits from an animal welfare perspective including greater freedom of movement and the ability to socialize. This comes at the expense, however, of aggressive interactions and lameness (Anil et al., 2005a; Backus et al., 1997; Pajor, 2002). Lameness is defined by Merriam-Webster (2015) as “having a body part and especially a limb so disabled as to impair freedom of movement”. Lameness in sows is critically important as it is responsible for 10% of sow removals from the herd (Anil et al., 2009; Nikkilä et al., 2013). Many of these sows may not have reach their reproductive potential, being culled on average between 2.1 and 2.6 parities compared with the average sow being culled for any other reasons between 4 and 4.4 parities (Engblom et al., 2008; Pluym et al., 2013a; Sasaki and Koketsu, 2010). Additionally, lame sows produce fewer pigs per year (Anil et al., 2009). There are many factors that affect sow lameness including the animals’ conformation, lesions, nutrition and type of flooring (Anil et al., 2007; Bryan et al., 1985a; Calderón Díaz, et al., 2013; de Carvalho et al., 2009; de Sevilla et al., 2009; Hill et al., 1983; Jørgensen and Sørensen, 1998; Pluym et al., 2011). Currently, lameness in swine breeding herds is evaluated visually. Several visual scoring methodologies have been developed in recent years and, when used by trained and experienced observers, lameness identification is accurate (Main et al., 2000). However, that can be challenging in an industry that can lack qualified personnel (Loula, 2000). Therefore, utilizing an objective mechanical approach could add value to the commercial swine industry.