Comparison of nursery pig behavior assessed using human observation and digital-image evaluation methodologies

摘要

Objectives: To design and implement a digital photograph system to document the pig response to a human observer in the home pen and then compare these results to a human observation in an approach-assessment paradigm. Materials and methods: An observer entered the nursery pen and crouched down with an outstretched arm for 15 seconds. A digital image was recorded, and the observer counted all pigs touching, oriented, and not oriented to the human. Each digital image was used to determine the snout and tail-base proximity to the index finger of the observer for pigs classified as Touch, Oriented, and Not Oriented when pens were divided into thirds and quarters. Postures and behaviors of pigs classified as Not Oriented were further delineated. Human observation and digital image were compared. Results: Most Not Oriented pigs in the digital image were standing, followed by sitting, with 2.5% piling. Both snout and tail-base proximities were closer for Touch pigs than for the other categories (P<.001). Regardless of how pens were divided, more pigs were located in the section farthest from the observer. There were no differences (P>.05) between human observation and digital-image evaluation for pigs classified as Touch. More pigs were classified as Oriented and fewer as Not Oriented for digital-image evaluation (P<.001). Implication: Human observation is a faster and practical application, but digital-image evaluation allows for more information to be collected.