Location: Genetics and Animal Breeding
Project Number: 3040-31000-099-002-T
Project Type: Trust Fund Cooperative Agreement
Start Date: May 1, 2019
End Date: Aug 1, 2022
Objective 1: Identify gilts with poor structure or joint health prior to their selection as replacement breeding animals. While there are numerous causes of lameness, two of the most important are animals with incorrect structure and animals poor joint health (mild osteochodrosis or osteoarthritis lesions). Assessment of body structure is extremely subjective and quite variable between observers while many young pigs with osteochondrosis do not present any perceptible visual symptoms. Therefore, we propose to objectively measure body structure and locomotion using multiple methods and collect blood samples to assess joint health. These data can be used to eliminate gilts with poor prognoses as well as will be used to conduct genome-wide association studies to detect genetic markers associated with lameness that can be used for selection. Objective 2: Identify sows that are mildly lame in late gestation using objective measures. By identifying sows in late gestation that are showing mild signs of lameness, they can be closely monitored to determine the impact this mild affliction has on their performance and well-being while nursing piglets. Research has shown that incidence of lameness is highest when sows wean their litters, so it is critical to understand the progression of impaired movement in sows in this phase of production. Sows will be assessed for defects of the hoof upon entering the farrowing room and then again when they re-enter the breeding facility. Genome-wide association analyses will be conducted on these data to detect genetic markers that can be used for selection. Objective 3: Develop a recommended treatment protocol to improve hoof health and prevent sows exhibiting mild signs of lameness in late gestation to become severely lame. While many producers treat sows with clear signs of lameness, sows presenting mild signs of lameness will be placed into a trial where they are provided pain relief or are not. Performance data for each sow and their litter during lactation will be monitored and then all sows will be re-evaluated for objective measures of lameness at weaning.
The approach will monitor gilts at approximately 5 months of age to identify early phenotypes that can be used to remove animals prior to reaching the breeding herd. These phenotypes will include measuring stride length of each foot and weight displacement via a pressure sensing mat, 3D and visual video imaging systems as well as metabolomic analysis of serum to create phenotypes that are predictive of body structure and joint health which can be incorporated in modern production systems. These phenotypes may also be useful to improve body structure in future generations via genomic selection based on markers identified in genome-wide association analyses. We will continue to study the female as she progresses through her productive lifetime through additional use of the pressure sensing mat and video monitoring each time the sow enters and leaves the farrowing barn. In addition, each sow will be assessed for foot lesions soon after entering the farrowing stall and then again after weaning her litter by visual assessment as well as thermal imaging. A pain relief treatment for sows presenting mild forms of lameness will be tested to determine if the treatment protocol improves production metrics as well as facilitates recovery of the animal. Antimicrobial treatments to all animals will be tested to determine if they prevent or cure hoof defects prior to the defect causing life-long lameness. The results of this treatment protocol will be used to develop a recommendation for producers on how to treat sows that are detected with low-grade lameness late in gestation.