Understanding how sows utilize their dynamic space envelope could assist animal scientists, agricultural engineers and veterinarians when considering the dynamic space needs in gestation housing. The primary goal of this project was to estimate the area utilized by multiparous lame and non-lame gestating sows as they lie down and stand up. A secondary objective was to characterize the postures and movements of the lying down and standing up postural sequences, and to identify possible differences between lame and non-lame sows. A third objective was to identify other leg risk factors for lameness in multiparous sows. Eighty-five multiparous sows were scored for walking lameness on a 3-point scale (1=sound, 2=mildly lame, 3=severely lame) when moved from their home gestation stall to a testing pen. Limb lesions such as callus, swellings and wounds were scored in the front and rear legs according to severity. Sows were video recorded for one lying-standing event at 30 60 and 90 days of gestation. The digital video camera was affixed on the ceiling, over the testing and the sow was filmed dorsally until she laid down and stood up one time, or if 2.5 hours elapsed from the start of the recording. The lying and standing behavioral sequence were cut from the video as still frames. Images were combined into a single image and measured by two different methods; either counting the number of pixels on the contour of the sows’ body or by overlaying a grid on the image of the sow. On the same gestation days, a second video recorded the sows’ profile in a gestation stall. From this secondary video, sow postures and movements that occurred during the lying-standing sequence were identified and the time taken to transition between movements was recorded. Furthermore, joint angulation at the knee, hock, front and rear pasterns were measured using digital images extracted from this secondary video on gilts.
Goal One: To estimate the area utilized by multiparous lame and non-lame gestation sows as they lie down and stand up: On average, sows used 1.2 ± 0.4 m2 to lie down and to stand up. There were no observed differences in the dynamic space required to perform the lying-down or standing-up sequence between lame and non-lame sows. Additionally, there was no difference in the space required between the two measuring methods used (i.e. either counting the number of pixels on the contour of the sows’ body or by overlaying a grid on the image of the sow). The dynamic space requirements found in this study are, smaller than those reported previously; however, they are similar to the static space lying requirements outlined in the European legislation (EU Council Directive 2008/120/EC). Additionally, the sows’ dynamic space requirement found in this study could be accommodated in a gestation stall. It is important to note that this does not include space needed to turn around or to move forward or backwards. We hypothesized that lame sows would need a greater dynamic space requirement because previous research has concluded that severely lame sows show uncontrolled movements while lying down. However, under the conditions of this study, lameness did not affect the dynamic space needed to lie-down and stand-up.
Goal Two: To characterize the postures and movements of the lying down and standing up postural sequences, and to identify possible differences between lame and non-lame sows: Lameness did not affect the time needed to perform the different movements of the lying-standing process. While lying, on average, sows took 13.9 seconds from kneeling to rotating their shoulders, 7.7 seconds from rotating their shoulders to lower their hindquarters and 20 seconds to complete the lying down sequence. While standing, on average, sows took 8 seconds from folding their legs to sitting, 6.9 seconds from sitting to standing and 9.8 seconds to complete the standing sequence. There were no differences between lame and non-lame sows in the movements performed In both the lying down and standing up sequences. It is important to note, that lameness was categorized as “mild” with only one sow being classified as “severe”. Nonetheless, results from this study could be important in the decision making process for new specifications regarding space needs for gestation sow housing in the USA.
Goal three: To identify other leg and toe and dew claw risk factors for non-lame and lame multiparous sows. Limb lesions such as calluses, swellings and wounds were not associated with the risk of lameness. Knee, front and rear pasterns’ joint angles were wider in lame gilts indicating a greater effort of the gilt to balance her body due to the discomfort she might be experiencing.
For more information, please contact Dr. Julia A. Calderón Díaz ([email protected] [email protected]), Dr. Kenneth Stalder ([email protected]) or Dr. Anna Johnson ([email protected])
