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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Genetics and Animal Breeding » Research » Publications at this Location » Publication #416943
Research Project: Multi-Dimension Phenotyping to Enhance Prediction of Performance in Swine

Location: Genetics and Animal Breeding

Title: Genomic analysis of mobility measures on 5-month-old gilts associated with structural soundness

Author
item OSTRAND, LEXI - University Of Nebraska
item Rempel, Lea
item Keel-Mercer, Brittney
item Snelling, Warren
item SCHMIDT, TY - University Of Nebraska
item PSOTA, ERIC - University Of Nebraska
item MOTE, BENNY - University Of Nebraska
item Rohrer, Gary

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/27/2024
Publication Date: 1/8/2025
Citation: Ostrand, L.M., Rempel, L.A., Keel, B.N., Snelling, W.M., Schmidt, T.B., Psota, E.T., Mote, B.E., Rohrer, G.A. 2025. Genomic analysis of mobility measures on 5-month-old gilts associated with structural soundness. Journal of Animal Science. 103. Article skaf001. https://doi.org/10.1093/jas/skaf001.
DOI: https://doi.org/10.1093/jas/skaf001

Interpretive Summary: If methods existed to identify gilts that will become lame in breeding herds, then these gilts could be redirected as market animals indirectly improving sow well-being, longevity, and increasing profitability. This study evaluated gilts (age 5 mo) and then observed those retained for breeding throughout their productive life. Data were collected from a pressure-sensing mat and from a week of video recording. Animals that were currently lame or were culled for poor leg structure tended to be less active, as determined by video data, took shorter strides, and had more variable step parameters, as determined by the pressure mat. Gilts that remained sound throughout production walked farther and made more turns in a day than retained gilts that later became lame. Genetic analysis indicated traits measured were moderately heritable and several genetic markers were identified which may be useful in selecting robust gilts capable of withstanding commercial environments. These objective measurements recorded on gilts at 5 mo of age have the ability to identify animals with poor leg structure prior to the development of lameness and can improve the longevity of current and future generations of breeding sows.

Technical Abstract: Sow lameness results in premature culling, causing economic loss and well-being issues. A study, utilizing a pressure-sensing mat (GAIT4) and video monitoring system (NUtrack), was conducted to identify objective measurements on gilts that are predictive of future lameness. Gilts (N = 3,656) were categorized to describe their lifetime soundness: SOUND, retained for breeding with no detected mobility issues; LAME_SOW, retained for breeding and detected lame as a sow; CULL_STR, not retained due to poor leg structure; LAME_GILT, not retained due to visible signs of lameness; and CULL, not retained due to reasons other than leg structure. The GAIT4 system creates a series of measurements for each hoof and a lameness score (GLS) while NUtrack records animal movement and posture durations each day. To determine if measurements from the GAIT4 and NUtrack systems were associated with lifetime soundness, mixed model analyses were conducted in R including fixed effects of breed of sire, contemporary group and lifetime soundness score, and random effect of animal. A second mixed model was run without lifetime soundness score and estimates of animal effects were then used to conduct ssGBLUP analyses using three generations of pedigree and genotypes from ~50k SNP on > 60% of phenotyped animals. Genomic heritabilities were estimated, SNP effects were back-solved and significance was based on Bonferroni-corrected permutation tests. GAIT4 traits indicative of lameness (LAME_GILT and CULL_STR vs. SOUND; P < 0.05) were the standard deviation of GLS, average stride length, and average stance time, while significant NUtrack measurements were eating, standing, lateral lying, total lying, speed, distance, and rotations. In addition, rotations differed (P < 0.05) between SOUND vs. LAME_SOW and distance tended to be different (P < 0.10). Estimates of heritability for predictive NUtrack traits were ~0.3 and GAIT4 traits were ~0.2. There were 382 significant SNP effects in 47 genomic regions, four regions on chromosomes 1, 4, 11, and 14 accounted for over 60% of the associations. Genome-level imputed genotypes linked several regions with possible causative genes. Objective measurements from the GAIT4 and NUtrack systems at 5 mo of age were heritable, able to detect unsound animals, and were associated with lifetime soundness.