Degree Type

Thesis

Date of Award

2012

Degree Name

Master of Science

Department

Animal Science

First Advisor

Anna K. Johnson

Abstract

The expectation from retailers and the public for food animal producers to continually evaluate and improve on-farm animal welfare practices will continue. The U.S. swine industry has the Pork Quality Plus education and assessment program and starting in 2011 began on-farm third party verification. However, the lack of an animal-human based measure in the current program has drawn criticism from some activist groups. Therefore, investigating the feasibility of collecting on-farm animal-human based measures that are repeatable, objective and meaningful is critical. The objective of the first study in this thesis was to build a nursery pen image capturing device that could produce a digital image concurrently with live human pig observation to allow comparisons between the live observation and digital image evaluation methodologies for pigs classified into "touch", "look", and "not" behavioral categories. The overall conclusion for pigs housed in small nursery pens was that a device could be built and used on farm. In addition, there were no differences between these two methodologies. The objective of the second study in this thesis was to compare live human observation with digital image evaluation methodologies for pigs classified into "touch", "look", and "not" behavioral categories in commercial nursery pens. The digital image evaluation resulted in the inclusion of more "look" and less "not" classified pigs compared to live human observation. The majority of pigs classified as "not" were standing and only 2.5% of pigs were classified as piling. The behavioral differences between the two methodologies may have included (1) live observer field of vision limitations (2) data collection time points for the methods differed and (3) pig and observer anatomy obstructions at the time of the count. The objective of the third study from this thesis was to compare live human observation and digital image evaluation for the same pig behavioral categories as well as to determine behavioral injection effects in commercial nursery pens. There was no difference between the live and digital methodologies for pigs classified as "touch", "look", "not", and "approach." There was no difference pre-injection for postures and behaviors. Post-injection, less Circumvent-PCVM treated pigs were classified as "touch" and "look" with more "not" compared to CircoFLEX/MycoFLEX and saline control treated pigs. When "not" pigs were broken down into behaviors and postures, fewer Circumvent-PCVM pigs were standing but more were sitting and lying compared to CircoFLEX/MycoFLEX and saline control pigs post-injection.

In conclusion, the live human observation methodology of classifying nursery pig behavior was the quicker on-farm method compared to digital image evaluation. The digital image allowed for more animal-human interaction measures to be collected i.e. behaviors, postures, location, and proximity from the human in the pen. Determining what activities the pigs are engaged in if not considered "approaching" would provide information to a producer, veterinarian, and/or assessor with respect to their overall comfort level. It would be erroneous to conclude that all pigs classified as "not" are fearful of humans in their home pen and therefore in a compromised welfare state. As a caveat, classifying pigs in the "not" category is time consuming and therefore the digital image evaluation methodology would likely not be accepted within an industry on-farm assessment program. Therefore, if "negative" behavior(s) (i.e. piling or escape) were counted instead of behaviors and postures considered to not negatively affect welfare, then only a few pigs in a pen would likely need to be counted and the remainder would be counted as "acceptable" or "not fearful." Therefore, when deciding upon which methodology (live human observation and digital image evaluation) to use for an animal-human interaction test, the decision will be based on it being practical, repeatable, meaningful, and fast.

Copyright Owner

Shawna Leigh Weimer

Language

en

File Format

application/pdf

File Size

176 pages

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