|Lay, Jr, Donald - Don|
Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/23/2007
Publication Date: 6/15/2007
Citation: Schenck, E.L., Mcmunn, K.A., Rosenstein, D., Nielsen, B.D., Richert, B.T., Marchant Forde, J.N., Lay Jr, D.C. 2007. Exercise increases bone density in the joints and limbs of gestating stall-housed gilts. Journal of Animal Science. 85(1):364.
Technical Abstract: Lameness in breeding age gilts and sows is a major cause of early culling, causing increase economic loses and welfare concerns. Stall housed sows tend to have more joint, foot and leg problems than group housed sows. The aims of this study was to determine if exercise would decrease lameness, and have an effect on the limbs of stall housed sows that are exercised versus not exercised. The study was composed of three treatment groups; control (C, n=8), high exercise (H, n=5, 121.9 m 2 d/wk and 426.7 m for 3 d/wk) and low exercise (L, n=5, 121.9 m 5 d/ wk). All gilts were stall housed for the duration of gestation and H and L gilts were exercised from d35 to 110 of gestation. Blood was taken on d -14, 35, 56, and 110 of gestation, and at the end of lactation via jugular veni-puncture and serum was collected. At the end of lactation, sows were sacrificed, and the left fore- and hind limbs were harvested. Specific muscles and bones from the fore and hind limbs were dissected and weighed and removed. Hooves were scored based on number and severity of lesions, cracks, and bruises. The patella and calcaneous from the left leg bone density was determined by dual energy x-ray (DEX) scans. All other bone density was determined by computed tomography (CT). Blood serum was analyzed for osteocalcin by an EIA. Osteocalcin concentrations in the L group were greater (P<0.05) than C at d 35 and 56, and tended to be greater (p<0.01) at d110. There was no difference in hoof scores, muscle/body weight ratio, or in bone mineral density of the patella or calcaneous (P>0.05). Bone density (mg/cm3) was greater (P<0.05) in the femur and the humerus of the L group compared to that of the C group, and tended (P<0.01) to be higher in the femur compared to the H group. The bone density of the radius of the H group was greater (P<0.05) than both L and C groups. Scapular and proximal humerus articular cartilage scores of the L group were greater (P<0.05) than both H and C groups. Exercise has some effect on bone, however the relationship is not clear at this point.