Graduate Studies
First Advisor
Ty B. Schmidt
Date of this Version
5-2024
Document Type
Article
Citation
A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science
Major: Animal Science
Under the supervision of Professor Ty B. Schmidt
Lincoln, Nebraska, May 2024
Alternate title: Evaluation of Nursery Pig Behavior after Lawsonia intracellularis Vaccination and Immune Challenge Utilizing the NUtrack Livestock Monitoring System
Abstract
This study aimed to evaluate the potential changes in active and passive behaviors of nursery pigs vaccinated for Lawsonia intracellularis and then subsequently challenged utilizing NUtrack. On day -3, ninety nursery pigs were stratified by body weight and randomly assigned to one of six pens (15 pigs/pen). On day 1, within each pen, pigs were randomly assigned to one of three treatment groups: Non-vaccinated (No-Vac), L. intracellularis vaccine 1 (Vac-1), and L. intracellularis vaccine 2 (Vac-2). On day 23, all pigs were challenged with an L. intracellularis intestinal homogenate. Following the challenge, pigs remained in assigned pens until study completion on day 45. Across the 45 days, pigs in both the Vac-2 treatment and the No-Vac treatment walked more (P ≤ 0.001) meters/day and had greater (P ≤ 0.01) revolutions than pigs in the Vac-1 treatment. While pigs in the Vac-1 treatment spent a reduced (P = 0.02) percentage of time standing when compared to pigs in the No-Vac treatment for the entire study period, pigs in the Vac-2 treatment were intermediate. For passive activities, pigs in the Vac-1 treatment spent a greater (P = 0.03) percentage of the total time lying across the study period than pigs in the No-Vac treatment, pigs in the Vac-2 treatment were intermediate. In addition to differences for the entire 45 days, there were also differences associated with the two periods of the trial (post-vaccination, d1-22, and post-challenge, d23-44). Post-vaccination pigs in the Vac-2 and No-Vac treatments walked more (P = 0.007) meters/day and had greater (P ≤ 0.001) revolutions than pigs in the Vac-1 treatment. During the post-vaccination period, pigs in the Vac-1 treatment tended to spend a greater (P = 0.07) percentage of time at the feeder when compared to Vac-2 and No-Vac treatments. Pigs in the Vac-2 treatment had greater (P ≤ 0.03) post-challenge gain and total gain when compared to pigs in the Vac-1 and No-Vac treatment. Overall, results indicate that Vac-2 pigs' activities were similar to pigs in the No-Vac treatment while having improved production efficiency compared to pigs in the No-Vac treatment.
Advisor: Ty B. Schmidt
Comments
Copyright 2024, Avery Vieregger. Used by permission