Characterization of genetic variation in soy sensitivity in pigs

Jessica Lynne Guernsey, Purdue University

Abstract

Sensitivity to soybean meal (SBM) protein in pigs causes reduced growth during the nursery period and potential loss of profit because of this poor growth. Knowing which genetic lines of pigs are SBM sensitive would be important information to control this reaction. The purpose of the present study was to characterize the genetic variation for SBM sensitivity in commercially available lines of pigs. The focus was to evaluate SBM sensitivity as it relates to the genetic sources of weaned pigs; the sources we evaluated included two sources of dams and four sources of sires. The four sire sources were further divided into nine total distinct lines. The nine sirelines were all derived from Yorkshire and Landrace crosses. One damsource was a Yorkshire x Landrace F1 cross and the other damsource was a Yorkshire x Chester F1 cross. These nine sirelines and two damsources were evaluated for standard production traits and as sources of variation in SBM sensitivity. SBM sensitivity was measured by challenging pigs with a high SBM-content diet, 28% SBM for 21 days post-weaning, followed with intradermal skin testing to assess reactions of individual pigs. Reactions were scored qualitatively on a scale ranging from 0-3. Reactions were used to assess the genetic sources for SBM sensitivity and to select young pigs to establish high- and low-reacting lines of pigs for further study. There were minimal differences between genetic sources for SBM reaction. There were no differences between damsources for SBM reaction variables, and there were limited differences between sirelines. The interaction between sireline and damsource was significant for soy flair and soy wheal reaction variables. Other sources of variation for SBM reaction which were not directly attributable to genetic differences were nursery average daily gain and weaning weight. Replicate was an identifiable significant source of random variation. SBM reaction was also shown to be correlated with peanut reaction. These results suggest that there are genetic differences between lines for SBM sensitivity. Due to the consistently significant sireline*damsource interaction, it seems that some of this genetic difference was due to non-additive effects.

Degree

M.S.

Advisors

Stewart, Purdue University.

Subject Area

Animal sciences

COinS