Prediction of variability in pig growth rate using immune and metabolism blood indicators

Alexandra Chatelet (1) , Nathalie Le Floc'H (1) , Florence Gondret (1) , Nicolas N.C. Friggens (2)

1 PEGASE - Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Elevage [Rennes]
2 MoSAR - Modélisation Systémique Appliquée aux Ruminants

Pig growth rate is influenced by metabolism and immune status. This study aimed to assess whether immune and metabolic blood indicators can predict variability in growth rate of two pig lines differing in their Residual Feed Intake or RFI (a measure of feed efficiency) and submitted to an immune challenge. A total of 160 growing pigs were allotted in a 2×2 factorial design comparing the two lines (low RFI or LRFI is more feed efficient vs high RFI or HRFI is less efficient) housed in good or poor hygiene conditions (clean vs dirty). This design permitted us to evaluate whether predictors of variability in growth rate applied across the different combinations of hygiene and line. Average Daily Gain (ADG, g/d) was calculated for 6 weeks (W0 to W6) and fasting blood samples were taken at W0, W3 and W6 to measure 47 variables related to immune system or metabolism. A preliminary descriptive Principal Component Analysis showed a great variability as well as strong multicollinearity within the 47 blood indicators measured at W3. In addition, the experimental design had introduced a great variability in growth rate, with ADG of the HRFI line housed in dirty conditions exhibiting the largest range. Thus, Partial Least Square (PLS) analyses were performed within each RFI line using the 47 variables measured at W3 to predict ADG. Several PLS models were fitted to estimate the proportion of explained ADG and the Root Mean Square Error of Prediction (RMSEP). Finally, a model reduction step was also performed to select the most relevant ADG predictors taking into account their biological meaning. Using the 47 variables and irrespective of the hygiene conditions, it was possible to explain 42% and 73% of ADG variations for the LRFI and HRFI, respectively. Within the 47 predictors, immune traits such as haptoglobin concentration and some amino acids (taurine, hydroxyproline) were associated with variation in growth rate. This study may provide useful information on biological pathways explaining the ability of pigs to cope with an immune challenge. Research has received funding from the EU FP7 Prohealth project (no. 613574)

Domaines: Science des productions animales

Alexandra Chatelet, Nathalie Le Floc'H, Florence Gondret, Nicolas N.C. Friggens. Prediction of variability in pig growth rate using immune and metabolism blood indicators. 68. Annual Meeting of the European Federation of Animal Science (EAAP), Aug 2017, Tallinn, Estonia. pp.118. ⟨hal-02943005⟩