Dynamic Space Utilization of Lame and Non-Lame Sows as Determined by Their Lying-Standing Sequence Profile

摘要

The primary objective of this project was to determine the dynamic space utilization for lame and non-lame sows during a lying-standing postural sequence. A secondary objective was to characterize the postures and movements for multiparous lame and sound sows and to identify differences in the lying and standing sequence. A total of 85 multiparous sows were used. Each sow was evaluated for walking lameness between their gestation stall to a pen using a 3-point scale (1 = normal to 3 = severely lame). Individual sows were moved to a pen on day 30, 60 and 90 of gestation and a ceiling mounted camera was installed above the pen to record a single lying-standing event. Observations ceased when the sow laid-down and stood-up or if 2.5 hours elapsed from recording commencement. Lying and standing sequence still frames were combined into a single image and measured in Adobe Photoshop Elements by counting the pixel number associated with contouring the sows' body or; counting squares on a grid that was overlaid on the sow's image. A second video of the sows' profile while standing in a gestation stall was collected on 30, 60 and 90 days of gestation. From this video, postures and movements that occurred during the lying-standing sequence were identified. Time (seconds) from kneeling to shoulder rotation (KSR), shoulder rotation to lying (SRHQ) and total time to lie (TLIE) were determined. In addition, latency to lie (LATENCY; minutes) and number of attempts (ATTEMPTS) to successfully lie were recorded. Time (seconds) to stand was defined as the first leg fold to sit (TLS), time from sit to rise (TSR), and total time to rise (TRISE) were recorded from the standing sequence. Data was analyzed using mixed model equations. Lameness was re-classified as non-lame (score 1) and lame (scores ≥ 2) and parity was re-classified as 0, 1 and 2+. On average, sows used 1.2 +/- 0.4 m2 to lie and to stand and there was no difference in the space required between the two measuring methods used (P > 0.05). Space required to lie and stand increased as gestation progressed (P < 0.05). Lameness was not a significant source of variation for any of the traits evaluated in this study (P > 0.05). On average, sows took 13.9 seconds for KSR, 7.7 seconds for SRHQ, 20.5 seconds for TLIE and 66.1 minutes for LATENCY. Furthermore, sows took 8.0 seconds for TLS, 6.9 sec for TSR, and 9.8 seconds for TRISE. Lame sows tended to take longer during KSR (15.5 vs. 11.9 +/- 1.59 seconds for lame and sound sows, respectively; P = 0.08), and spent less time standing (54.1 vs. 69.8 +/- 6.20 minutes for lame and sound sows, respectively; P = 0.06) when compared to sound sows. Additionally, lame sows tended to be more likely to sit while transitioning from lying to standing compared with sound sows ( P = 0.07). Gestation day and parity were not associated with the time taken for the different movements in the lying down sequence ( P > 0.05). There were no significant associations between gestation day, lameness status or parity and the sow's attempts to lie. Sows in their first parity had greater TLS compared with gilts (20.9 vs. 4.7 +/- 3.01 seconds; P < 0.05) and sows parity 2+ (20.9 vs. 5.5 +/- 3.62 seconds; P <0.05). Parity 1 sows tended (P = 0.09) to take 8.1- and 6.7 seconds more for TRISE than gilts and 2+ sows; respectively (16.0 vs. 7.9 +/- 1.9 and 9.3 +/- 3.3 seconds; P < 0.10). There was no significant association between lameness and any limb lesions evaluated in the present study (P > 0.05). Under the conditions of this study, lameness did not influence dynamic space requirements or the time taken for the different lying-standing sequence movements. However, the observed lameness was mild and thus, it might not have been severe enough to affect the studied traits. The results from this study could be important when making breeding herd housing specifications decisions regarding sow gestation space needs in the U.S.