218 Quantifying resilience in growing pigs under a heavy disease challenge using daily individual feed intake records. (5th December 2019)

• Record Type: Journal Article
• Authors: Putz, Austin M; Harding, John; Dyck, Micheal; Canada, PigGen; Fortin, Frederic; Plastow, Graham; Dekkers, Jack C
• Is Part Of: Journal of animal science. Volume 97(2019)Supplement 3
• Page Start: 45
• Page End: 46
• Publication Date: 2019-12-05
• Subjects: resilience -- disease resistance -- feed intake -- root mean square error -- quantile regression; Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.1093/jas/skz258.090
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: Resilience is defined as the ability to maintain productivity through any number of stressors such as disease or heat stress. A total of 2273 animals, in groups of ~60–75 piglets, were sent through a natural disease challenge barn every three weeks that consisted of three phases: i) a healthy quarantine nursery to collect immune parameters, ii) a challenge nursery, and iii) a challenged finishing unit which was attached to the challenge nursery. Individual feed intake (FI) was collected in the finishing unit with IVOG® feeders and aggregated into daily totals. Three resilience phenotypes were extracted from the individual trends in feed intake over time, including the root mean square error (RMSE), the quantile regression (QR), and run of depression (ROD) phenotypes. The RMSE phenotype was calculated by fitting a simple linear regression of FI on age within animal and taking the square root of the average squared residual from the model. To calculate the QR phenotype, a 5% quantile regression was fitted across all daily feed intake records to set a lower bound for off-feed days. The QR phenotype was quantified as the proportion of days within animal that fell below the overall quantile regression line. The ROD phenotype was calculated by fitting a within animal linear regression line, flagging extended consecutive stretches of days below that regression line (i.e. a ROD), and calculating the percentage of days that fall within a ROD for each animal. Heritability estimates for the FI resilience phenotypes ranged from 0.10±0.04 to 0.17±0.04. Genetic correlations of the FI resilience phenotypes with mortality and treatment rate ranged from 0.66±20 to 0.94±0.20. This research demonstrates that resilience phenotypes can effectively quantify resilience and can add value to a breeding program to improve resilience to many stressors. Funded by Genome Canada, Genome Alberta, and PigGen Canada.