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Genetic determinism of resilience to unrecorded challenges in pigs
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Edité par CCSD ; Wageningen Academic Publishers -
Session 85. Genetics of novel health and welfare traits. International audience. Selection of animals able to maintain their performance under variable environmental conditions is needed. Pigsin selection farms are raised in a monitored and controlled environment (e.g. temperature). However, pigs couldbe exposed to challenges/disturbances unrecorded and from unknown origin. Therefore, resilience in pigs remainsimportant. The probability of the occurrence of an unrecorded environmental challenge at a given day was estimatedfrom daily feed intake (DFI) data, and the genetic determinism of resilience to such events was evaluated.In total, 186,242 DFI records recorded automatically from 2,517 Large White males were used. The pedigreeinvolved 5,649 individuals. For each day (within each batch), the probability of the occurrence of a challenge wascomputed via a mixture model. As a result, unrecorded events of environmental challenges affecting pigs’ DFIwere identified. Days with a high probability of having a high coefficient of variation (CV) were related to the occurrenceof an environmental challenge. The probabilities (p) of high CV (stressful day) were used as a covariatein a reaction norm model (RNM) as an environmental descriptor, ranging from a non-challenging environment(p=0) to a challenging one (p=1). Variance components were estimated using the average information restrictedmaximum likelihood method. The mean probability of being a day with a high CV was 0.10; thus most of thedays have a low probability of the occurrence of a challenge. The genetic correlation between level and slopewas 0.06±0.13 in RNM. This value suggests that selecting for decreased DFI would have a minimal effect on theanimal’s sensitivity to challenging environmental conditions.Session