Submitted to: Animal Biotechnology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/27/2005
Publication Date: 4/1/2006
Citation: Galina-Pantoja, L., Solano Aguilar, G., Mellencamp, M.A., Bastiaansen, J., Cabrera, R., Lunney, J.K. 2006. Relationship between immune cell phenotypes and pig growth in a commercial farm. Animal Biotechnology. 17:81-98 Interpretive Summary: Pig breeders want to produce healthy pigs under efficient production condition, resulting in high quality and safe pork products. This study was aimed at determining whether there might be immune markers that would correlate with, and thus be predictive biomarkers for, efficient pig production parameters. For these analyses production performance of 140 pigs from 3 commercial genotypes was monitored throughout the pig’s lifetime. [A repeat analysis of 250 pigs the following year confirmed these data.] A one-time immune sampling strategy was developed: at 6-7 weeks of age the pigs were bled in the nursery and the percentage of specific immune cell subsets in peripheral blood was determined using immunostaining and flow cytometric analysis. The predictive effect of the immune cell subset markers and lymphocyte proliferation on production traits was then statistically analyzed. The results showed that indeed there were certain immune cell subsets that appeared to predict growth during the entire productive life of the pig, or were associated with better carcass weight and feed conversion. These immune cells included natural killer cells (CD2+/CD16+ cells) that are essential regulators of innate immune responses, and a subset of T cells (CD8+ cells) that kill off cells infected with viruses. These results affirm that genetic selection for certain immune parameters, i.e., immune cell subsets, could improve production traits in pigs grown in representative commercial environments. These immune cell subsets could be important biomarkers involved with the inherent ability of the pig to efficiently grow and produce better carcass weight
Technical Abstract: The objective of this study was to evaluate the relationship between the level and function of circulating immune cells with average daily gain, live and carcass measurements, feed intake, and feed conversion. Production performance of 140 pigs from 3 commercial genotypes was monitored throughout the pig’s lifetime. Pigs were moved in weekly batches through the nursery, and growing-finishing rooms at specific target weights. Animals were individually weighed at birth and at weaning, and then every 2 weeks while they were “on test” until they were “off test” and sent to the slaughterhouse. At 6-7 weeks of age the pigs were bled in the nursery. The percentage of immune cell subsets and lymphocyte proliferation was estimated using swine monoclonal antibodies and flow cytometric analysis. The predictive effect of the immune cell subset markers and lymphocyte proliferation on production traits was statistically analyzed. The results indicated that the relative numbers of several peripheral cell subsets including CD16+, CD2+/CD16+, and CD8+ lymphocytes, appear to predict growth during the entire productive life of the pig. Larger relative percentages of lymphocytes expressing CD16+, CD2+/CD16+, and CD8+ receptors in blood resulted in a reduction in average daily gain. In addition, high percentages of SLA-DQ+ cells were associated with better carcass weight and feed conversion. The CD16+, CD2+/CD16+, CD8+ and SLA-DQ cell subsets appear to be important biomarkers involved with the inherent ability of the pig to efficiently grow and produce better carcass weight in representative commercial environments.