Genotype effects on pig immunity

Outdoor intensive swine production systems are common m the United Kingdom and are being explored m the southern United States. The objectives of study 1 were to determine the effects of production system and genotype on piglet weight gain, blood hemoglobin, white blood cell numbers and Immunoglobulin G concentrations. These data showed that environment and age influenced piglet Hb levels and WBC and that genotype influenced IgG levels shortly after birth, hi the second part of the study, production systems and treatment levels of iron were studied to observe the effects to the measures observed m the first part of the study. Outdoor-reared piglets had some signs of stress, but had similar survival rates as indoor-reared Utters. However, these data showed that supplemental iron may not be necessary m outdoor production systems.

Newer genetic lines of pigs are being used in indoor and outdoor production systems. The objectives of study 2 were to describe the effects of the maternal sow line genotype, environment, and the genotype by environment interactions on the same measures as in the first study along with neutrophil chemotaxis, Cortisol concentrations and lymphocyte blastogenesis. Exp-94 sows had lower lymphocyte blastogenesis (LTA) at lower mitogen doses and higher natural killer cell (NK) cytotoxicity than the C-15 sows. Experiment 2 sought to determine the effects of genotype on the immune system of nursery-age offspring of the experimental Lines bred to a common PIC 405 boar line. The Exp-94 X 405 pigs had higher WBC numbers compared to the C-15 X 405 pigs. The Exp-94 Ime had marginally increased immunity to viral disease and reduced systemic bacterial immunity than the C-15 line.