Evaluation of the behavior of sows from weaning to 10 days post-weaning

Moest, Nicole K

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https://hdl.handle.net/2142/117704 Copy

Description

Title

Evaluation of the behavior of sows from weaning to 10 days post-weaning

Author(s)

Moest, Nicole K

Issue Date

2022-08-16

Director of Research (if dissertation) or Advisor (if thesis)

Ellis, Michael

Department of Study

Animal Sciences

Discipline

Animal Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

Sow, estrus, posture

Abstract

The behavior of sows changes as they approach estrus and such changes have the potential to be used to predict the onset of estrus and the optimum time for insemination. There is limited published information on the changes in behavior of sows over the estrus cycle, particularly for those that are individually housed in gestation crates. The objective of this thesis was to provide an overview of endocrine and behavioral changes in sows during the estrus cycle and review approaches to estrus detection. In addition, a study was carried out to evaluate changes in posture of sows during the period immediately after weaning. This involved a cross-sectional survey involving 99 multi-parous sows that were weaned in 7 groups over time. The sows were housed in individual stalls and continuous video recording was carried out over an 11-day period following weaning. Videos were monitored by the same trained observer to record the posture of the sows (lying, standing, and sitting positions). Two sampling methods were used to monitor the videos over the 11-day study period. Firstly, scan sampling was carried out with the posture of each sow being recorded every 5 minutes, and, secondly, the videos were scanned continuously and the time that the sows were in each posture was recorded. There was no effect (P > 0.05) of sampling method for the percentage of observations or time that the sows exhibited any of the postures. During the study period, 96 of the sows exhibited the standing reflex, with the first display of this being at an average of 5.8 days following weaning (range 4 to 7 days). The number of days that sows exhibited the standing reflex averaged 2.6 (±0.56) days. Over the 11-day study period, the sows spent an average of 76.5 % of the time in the lying posture and 20.0 and 3.6 % of the time standing and sitting, respectively. The time that the sows were active (i.e., either standing or sitting) was greater on Day 5 and 6 post-weaning (28.4 and 27.9 % of time, respectively) than on the two previous days (Day 3 and 4 post-weaning; 18.7 and 21.0 % of time, respectively). This period of increased active postures corresponded to the days when most sows first exhibited the standing reflex. The results of this study suggest that changes in posture associated with the onset of estrus could provide the basis of an automated system to predict the onset of estrus and, therefore, the optimum time to inseminate sows. However, a fuller understanding of the extent of and causes of variation between individual sows in changes in posture during this critical period is needed before this approach can be advanced.

Graduation Semester

2022-12

Type of Resource

Thesis

Copyright and License Information

Copyright 2022 Nicole Moest

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