Objective evaluation of female feet and leg joint conformation at time of selection and post first parity in swine1

• Published in: Journal of animal science 2018-09, Vol.96 (9), p.3549-3557
• Main Authors: Stock, Joseph D, Calderón Díaz, Julia A, Rothschild, Max F, Mote, Benny E, Stalder, Kenneth J
• Format: Article
• Language: English
• Subjects: Animal Genetics and Genomics; Animals; Female; Foot; Foot Diseases - veterinary; Forelimb; Hindlimb; Parity; Phenotype; Pregnancy; Swine
• ISSN: 0021-8812; 1525-3163; 1525-3163
• DOI: 10.1093/jas/sky227

Abstract Feet and legs of replacement females were objectively evaluated at selection, i.e., approximately 150 d of age (n = 319) and post first parity, i.e., any time after weaning of first litter and before second parturition (n = 277) to 1) compare feet and leg joint angle ranges between selection and post first parity; 2) identify feet and leg joint angle differences between selection and first 3 wk of second gestation; 3) identify feet and leg joint angle differences between farms and gestation days during second gestation; and 4) obtain genetic variance components for conformation angles for the two time points measured. Angles for carpal joint (knee), metacarpophalangeal joint (front pastern), metatarsophalangeal joint (rear pastern), tarsal joint (hock), and rear stance were measured using image analysis software. Between selection and post first parity, significant differences were observed for all joints measured (P < 0.05). Knee, front and rear pastern angles were less (more flexion), and hock angles were greater (less flexion) as age progressed (P < 0.05), while the rear stance pattern was less (feet further under center) at selection than post first parity (only including measures during first 3 wk of second gestation). Only using post first parity leg conformation information, farm was a significant source of variation for front and rear pasterns and rear stance angle measurements (P < 0.05). Knee angle was less (more flexion; P < 0.05) as gestation age progressed. Heritability estimates were low to moderate (0.04–0.35) for all traits measured across time points. Genetic correlations between the same joints at different time points were high (>0.8) between the front leg joints and low (