Do Lame Sows Need More Time to Stand up?

Lameness is a prominent disease in swine production and it might affect the way sows interact with their environment. The objectives of this study were to determine the time required and the behavioral sequence to move from lying to standing for lame and non-lame sows. Eighty-five multiparous sows (parity range 1 to 4) were enrolled. Prior to recording, sows were scored for lameness while walking on a 3-point scale, (1 = normal to 3 = severely lame). Sows were moved into a gestation stall where they were digitally video recorded continuously (30 frames/s) for one standing up event on days 30, 60 and 90 of gestation. Time (sec) to stand up was defined as the first leg fold to sit (TLS), time from sit to rise (TSR), and total time to rise (TRISE). The frequency of TLS, TSR and TRISE were also collected. Sows were re-classified as sound or lame and parities were re-classified as 1, 2, and ≥ 3 for statistical analysis. The likelihood of performing the different movements for the standing sequence was analyzed using logistic regression. Time variables were analyzed using mixed model equation methods. Models included gestation day, lameness status and parity. There were no significant associations between gestation day, parity, lameness and the likelihood of performing different movements during the standing up behavioral sequence. However, lame sows tended to be more likely to sit while transitioning from lying to standing compared with sound sows (P = 0.07). On average sows took 8.0 sec for TLS, 6.9 sec for TSR, and 9.8 sec for TRISE. Lameness did not affect the time taken for TLS, TSR and TRISE (P > 0.05). Parity 2 sows had greater TLS compared with parity 1 sows (20.9 vs. 4.7 ± 3.01 sec; P < 0.05) and parity ≥ 3 (20.9 vs. 5.5 ± 3.62 sec; P <0.05). Additionally, parity 2 sows tended (P =0.09) to take 8.1 and 6.7 sec more for TRISE when compared to parity 1 and ≥ 3 sows; respectively (16.0 vs. 7.9 ± 1.9 and 9.3 ± 3.3 sec; P < 0.10). Under the conditions of this study, lameness did not influence the timings or order of the standing up sequence. However, lameness recorded was mild and thus, it might not have been severe enough to affect the sequence. Other factors such as parity seem to be related with timing of the standing sequence.