The study took place on a 5000 sow commercial swine farm. All sows were evaluated in group pens prior to enrollment of study by an experienced veterinarian. Sows with any evidence of disease or injury (with the exception of lameness) were ineligible for enrollment. At enrollment, sows (100-109 day of gestation) were evaluated for lameness by one trained veterinarian using a 1-3 walking and standing lameness scoring systems (1. Non-lame, 2. Lame, and 3. Severely lame; non-weight bearing on one leg). Sows were blocked by parity and assigned to one of four treatments based on their lameness score at enrollment 1) Lame Control (LC; n=45); 2) Lame Rubber Mat (LR; n= 48); 3) Non-Lame Control (NLC; n= 61); and 4) Non-Lame Rubber Mat (NLR; n =59). The control treatment (C) consisted of a standard farrowing crate with slatted flooring in the sow and piglet area, while the rubber mat treatment (R) consisted of a farrowing crate fitted with a perforated rubber boar mat (Heavy duty rubber mat, FarmerBoy Ag, $78.08). Mats covered an area from the front of the sows shoulder to their hindquarters and remained in the farrowing crate until weaning. Once piglets were weaned and sows moved back to breeding, mats were removed from all crates, power-washed and disinfected between each use and reused the following week.
Lameness scores were collected weekly for each sow by a trained veterinarian utilizing the standing scoring system described previously. To evaluate the effect of lameness between the time of farrowing to the time of weaning, sows were grouped into one of four lameness categories at the end of lactation; 1. Lame-Lame (LL); sows receiving a lameness score ≥1 in gestation and at weaning (n=39); 2. Lame-Non-lame (LN; sows receiving a lameness score of ≥1 in gestation and a score of 0 at weaning (n=51); 3. Non-lame-Non-Lame (NN); sows receiving a lameness score 0 in gestation and at weaning (n=82); and, 4. Non-lame- Lame (NL); sows receiving a lameness score of 0 in gestation and a score ≥1 at weaning (n=25).
Additional measurements included sow body weight, body condition score, lesion scores, and behavior (time spent lying, standing, sitting, drinking, nursing or eating). Measurements were collected weekly until weaning. Production data was also collected and included total piglets born, number born alive, stillborns, mummies, total weaned, total cross-fostered and f piglet mortality (low viability, deformed, micro piglet, spraddle legged, starved, rupture, crushed and injured).
Lameness severity was not affected by the presence of a rubber mat placed in the farrowing crate. Lameness was also not affected by sow body weight or body condition. Lesions present on the skin of the sow decreased over the time the sow was housed in the farrowing crate and the presence of the rubber mat did not increase the number of lesions. The decrease in lesions over time is likely a result of sows being housed individually (eliminating aggressive interactions between sows) and providing time for the lesions to heal.