Source: NORTH DAKOTA STATE UNIV submitted to
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
Funding Source
Reporting Frequency
Accession No.
Grant No.
Project No.
Proposal No.
Multistate No.
Program Code
Project Start Date
Jul 1, 2020
Project End Date
Jun 30, 2023
Grant Year
Project Director
Byrd, C. J.
Recipient Organization
FARGO,ND 58105
Performing Department
Animal Sciences
Non Technical Summary
When pigs are approximately 6 months of age and ready to go to the processing plant, they are required to walk onto a truck trailer to be transported. The process of walking from their pens to the trailer often results in heightened stress, a reluctance to move and potential injury, particularly when they are required to ascend an unfamiliar ramp to walk into the trailer. Stress and injuries related to loading, transport, and unloading reduce animal welfare and result in significant economic losses. The purpose of this study is to evaluate a strategy for reducing pig stress associated with walking up the ramp during trailer loading. Pigs will be given access to a small ramp within their pens from approximately 3-8 weeks of age. During this time, ramp usage and the effect of the ramp on pig behavioral interaction within the pen will be evaluated. At approximately 8 weeks of age, the ramp will be removed for the remainder of their growing period (i.e. 4 months). Following the growing period, pig behavior will be evaluated during trailer loading to see if early-life ramp exposure reduces the amount of stress they experience as they ascend the ramp into the trailer. The study will also investigate whether early-life ramp exposure makes it easier for the animal caretakers to handle the pigs during loading and unloading. We hypothesize that early-life pig exposure to a ramp will result in reduced behavioral and physiological indicators of stress, fewer injuries, faster loading and unloading times and decreased required effort by animal caretakers to safely move the pigs to and from the trailer. If successful, early-life exposure to a small ramp would be an easily adoptable strategy, resulting in improved swine welfare at loading and increased economic benefit for the producer.
Animal Health Component
Research Effort Categories

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
Goals / Objectives
Our overall goal is to mitigate a key problem of international importance: the loss associated with stress, injury, and death during transport of market hogs. In addition to diminishing animal well-being, transport losses at marketing occur after hogs have consumed their maximum resources, making them especially harmful to profitability and sustainability.Pig stress is reduced by easier loading, and injury and death may also be reduced. Our preliminary data indicate that a simple adaptation, providing a ramp in nursery pig housing, substantially decreases the amount of time it takes to load market hogs up a ramp, while alsodecreasing nursery pig fighting and maintaining growth.The goals of the proposed study are to validate our preliminary findings in a commercial-type production system and to expand the measured outcomes. Supporting objectives include measuring the effects of ramped nursery housing on loading and unloading speed and ease at marketing, stress to pigs in the nursery and at marketing, and pig condition at the processing facility. We will achieve the study objectives by comparing the described outcomes between pigs housed in conventional flat nursery pens and pigs housed in nursery pens containing a simple ramp and platform.The proposed project targets Program Area Code A1251, "Welfare and Well-being of Agricultural Animals". It will fulfill the Program Area Priorities by promoting the development of a new management approach that safeguards both animal welfare and sustainable production efficiency, and by creating improvement in handling and transportation to decrease injury and distress.
Project Methods
Nursery Phase:At weaning, pigs will be randomly assigned to two nursery treatments: 1) access to a ramp (RAMP), or 2) a standard flat pen (CONT). A single ramp (20° angle) will be placed in the nursery pens housing RAMP pigs. There will be resting platform at the top of the ramp, with rubberized flooring and enough area to accommodate all of the pigs in the pen early in the nursery phase. Pigs in the CONT treatment will be placed in a conventional pen of the same area, but without a ramp. The pigs will be in a wean-to-finish barn and will not be moved from their pens between weaning and marketing.Data to be collected during the nursery phase (approximately 6 weeks):A. Feed consumption amounts will be recorded for each pen.B. Tear stain scoring will be conducted after one week in the nursery as a measure of physiological stress; this measure has been shown to correlate with sympathetic nervous system activity (Marchant-Forde and Marchant-Forde, 2014), piglet aggression (DeBoer et al., 2015), and piglet exposure to novel environments (Telkänranta et al., 2015).C. Shoulder, flank, and ham lesions will be scored (4 category scoring system; Barton-Gade et al., 1995) after one week in the nursery as an indicator of pig aggression occurring in the pen.D. Pig behavioral data will be recorded via video camera during daylight hours every day for the first 7 days following weaning and once a week for the remaining 5 weeks to assess the effect of ramp presence on behavioral indicators of stress and pig welfare. Behaviors of interest include feeding, drinking, posture, and aggressive interactions between pen mates.E. Daily observations (lameness, illness, treatment, mortality) will be recorded by farm staff.F. Pen weights will be collected at the beginning and end of the nursery phase.Grow/Finish Phase:After approximately 6 weeks (the end of the nursery phase), ramps will be removed from the pens. Pigs will experience typical housing and husbandry practices in the grow/finish phase.Measures to be collected during the grow/finish phase:A. Pig body weight (averaged by pen) will be collected every 2-3 weeks this phase (on the same schedule for all pens), and pen feed intake data will be collected.B. Daily observations (lameness, illness, treatment, mortality) will be recorded by farm staff.Transport:When the pigs reach market weight, they will be loaded and transported to a commercial slaughter facility. Pigs will be moved with their pen conspecifics and encouraged to walk onto the ramp and trailer using a sorting board.Measures to be collected during loading:A. The amount of time it takes for each group to navigate the ramp leading to the transport trailer will be recorded. No aids other than the sorting board will be used for encouragement, unless a pig takes more than 3 min to load. Such pigs will be categorized as "hard to load".B. Individual refusals, slips, and falls will be counted.C. Instantaneous heart rate of the handler will be recorded to approximate changes to heart rate and heart rate variability in response to pig handling.Measures to be collected during unloading:A. The amount of time it takes the hogs to navigate the ramp when leaving the transport trailer will be measured.B. Individual refusals, slips, and falls will be counted.C. Non-ambulatory and dead pigs and pigs displaying injuries, open mouth breathing, and skin discoloration will be quantified.Statistical AnalysisData will be analyzed using the mixed procedure in SAS (v. 9.4; SAS Institute, Inc., Cary, NC). Residuals will be evaluated for normality and data will be transformed as necessary. Fixed effects will include repetition, treatment, day, and their interactions. Depending on the trait and the number of observations, repeated measures on a pen (either across time or across pigs) will be accounted for using a repeated or random statement in the mixed procedure. For repeated measures, different covariance structures will be tested and the best fit will be chosen using the Akaike Information Criterion. Treatment effects will be considered significant at the P ≤ 0.05 level.Communication of Results to Appropriate AudiencesResults will be distributed and shared via peer-reviewed journals (e.g. Journal of Animal Science, Applied Animal Behaviour Science), national and international scientific meetings (e.g. American Society of Animal Science, International Society for Applied Ethology), and additional extension bulletins and popular press opportunities (e.g. National Hog Farmer).

Progress 07/01/21 to 06/30/22

Target Audience: Nothing Reported Changes/Problems:Only 20 total commerical pens (10 pens for each treatment; approximately 500 total pigs)were utilized in the data collection instead of 40 pens. We had difficulty obtaining ramp fabrication supplies in time before the project needed to be initiated due to the SDSU barn's production schedule. With the large number of pigs raised in 20 pens, we do not anticipate major effects on the results. What opportunities for training and professional development has the project provided?One-on-one mentoring of a MS student has occured throughout the entire project duration. The student has gained experience in experimental design, statistical design, behavioral data collection and analysis, heart rate variability data collection, and some public speaking (through courses on campus). How have the results been disseminated to communities of interest?No, results will be disseminated once data have been analyzed. What do you plan to do during the next reporting period to accomplish the goals?After the 31st, we will have all of our data collected. Behavioral observation of the video collected during thestudywill occur September - December. The MSstudent funded through the project will present her results at a professional scientific meeting during Spring 2023. The MS studenthas a tentative graduatation date of Summer 2023. At that point, we will likely submit the results of the study for peer reviewed publication.

What was accomplished under these goals? Project data collection began in March 2022 as weaned pigs arrived at SDSU's wean-to-finish barn. Behavioral video collection occured between March and August 2022 to determine whether early-life exposure to a small ramp would reduce aggression and improve feed efficiency during the nursery and grow-finish periods. On August 3rd, we began the trailer loading aspect of the study, where we will evlaute whether presence of a ramp during the nursery period induces improved loading/unloading of the truck trailer at market weight (speed up the ramp, reduced behavioral stress associated with loading/unloading). Our 7th and final loading/unloading period will take place next week, August 31st.


    Progress 07/01/20 to 06/30/21

    Target Audience: Nothing Reported Changes/Problems:COVID-19 led to the loss of our experimental location. We have identified a new location (SDSU's wean-to-finish facility) for the experiment, however, it is likely that we will not have the opportunity to attain the sample size we had hoped. We are now looking at 40 pens total instead of approximately 70. Additionally, we will have to pay a fee for animal use that was not a requirement for the previous location.The reduction in pen numbers (and therefore, the reduction in ramp costs) will allow us to pay for the fees. The graduate student selected for this project is an international student. Border closures last year due to COVID-19 did not allow her to travel to the U.S. to begin her studies. She has officially arrived at NDSU and began her assistantship on August 16th, 2021. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?The project will be officially initiated in early October at South Dakota State's commercial wean to finish facility. A graduate student has been identified for the project and she officially started at North Dakota State University as a graduate research assistant on August 15, 2021. Over this next reporting period, all on-farm, transport, and production plantdata will be collected, swine behavior will be collected from recorded video, and analysis of the data will begin.

    What was accomplished under these goals? Project has not been initiated due to COVID-19 related difficulties that led to a loss of experimental locationand inability to enroll an international graduate student identified for the project.