Animal Science, Department of


Document Type


Date of this Version



Iowa State University Animal Industry Report 2016


Copyright 2016 Iowa State University of Science and Technology.


This study is a portion from the validation process of an

objective methodology to measure feet and leg joint angles

and to evaluate their relationship with sow longevity. Five

feet and leg conformation traits (knee, hock, front and rear

pasterns and rear stance) that have been described in the

literature as being related with sow longevity were selected

for this study. Profile and rear stance digital images were

obtained from 277 sows during their 2nd gestation (26.7 ±

17.2 days of gestation; range 0 to 87 days). Sows were

obtained from a single gilt population and were moved to

three different farms. Significant differences (P < 0.05)

between farms were identified in the knee, both pasterns and

the rear stance joint angle measurements. Asymmetric joint

angle measurements (i.e. difference in the joint angle

between the left and right legs) were identified for the knee,

and both pasterns. Knee, front pastern and hock joint angles

changed as gestation progressed. Results suggest that

environmental factors are related with variation in joint

angles. However, as the differences in joint angles are

relatively small, they may not be biologically relevant.