Impact of lameness and claw lesions in sows on welfare, health and production

The aim of this paper is to review existing literature concerning the impact of lameness and claw lesions on welfare, health and production of sows. When using the five freedoms, a common method to conceptualize animal welfare, to assess the impact of lameness, it appears that lameness as a single disease, may affect all of the freedoms. There is a wide variability with respect to the impact of claw lesions on welfare of sows, because only a proportion of animals are affected. Lameness affects welfare due to physically reduced locomotion ability, pain or general discomfort and sickness behavior. Cross-sectional studies show that the within-herd prevalence of sow lameness is quite high and may range from 8.8% to 16.9%. There are several reasons for lameness and claw lesions and they are very difficult to be identified during herd-level clinical examinations. Therefore, many researchers have studied the sows post-mortem and quite often found more than one lesion likely to cause lameness. Not all lesions are associated with lameness, but the location and severity of the lesions are important factors. Lameness can also affect the general health of the sow and predispose to loss of body condition, shoulder lesions and urogenital infections. Longevity of lame sows is decreased when compared with that of healthy-legged animals. Acutely and severely lame sows are removed immediately from the herd, and chronic, less severe lameness can affect the performance of sows and thus indirectly lead to culling. However, only few articles report about production or fertility figures of lame vs non-lame sows, except for ample data on longevity. In conclusion, lameness of sows is an important welfare and health problem and may also severely affect the profitability of sow herds.