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Does lameness affect the lying down sequence in sows?
This study was designed to identify and pictorially depict differences in the lying down sequence (i.e. postures adopted and movements during the process) in non-lame and lame gestating sows. Ten multiparous sows (average parity 3.5 ± 1.6) with different degrees of lameness on the rear legs (lameness scored from 0 = non-lame to 5 = non-ambulatory) were used for this study. Two sows were sound (score 0), 2 sows had a score of 1 (general stiffness, non-lame), 3 sows had a score of 2 (mildly lame), 2 sows had a score of 3 (lame, would not place weight on affected limb) and 1 sow had a score of 4 (severely lame). Sows were removed from their gestation stalls and moved to a gestation pen where they were video recorded for one lying down event after feeding time. The digital video camera was positioned at the rear of the individual pen where the profile of the sow was visible during video recording. Observations ceased when the sow successfully lied down. From the video recording, 10 picture frames per second were extracted using AVcutty v3.5 and postures and movements that occurred during the lying down sequence were identified. Finally, a set of three images per sow were selected to pictorially depict the lying down sequence. In the present study, we did not observe differences among lameness scores in the different postures or movements during the lying down sequence from the video recording. All the sows followed the lying sequences previously described by Seaton Baxter in 1984 where the i) the sow drops into a kneeling position, ii) then the sow rotates the upper part of her body to bring a shoulder and side of the head to rest on to the floor and iii) finally, the sow lowers her hindquarters and finishes in either ventral or lateral recumbency; except for the sow that received a lameness score of 4 that showed uncontrolled lying down behavior (i.e. losing control on one or more limbs and rapidly falling down) and finished the sequence in a “dog sitting” position. Results suggest that lameness scores do not greatly affect the lying down sequence. However, this could be due to the limited sample size and/or that lameness recorded in this study was not severe enough to affect the lying down sequence. Further studies are required using a greater sample size that is more representative of all lameness scores.
Keywords: lameness, lying down sequence, pictorial depiction