Genetic association between feed intake and feed intake behaviour at different stages of growth of group-housed boars

Abstract

Abstract Voluntary feed intake, feed intake pattern and performance traits were recorded on 3188 group housed boars of Landrace and Large White tested from day 100 to day 170. Measurements of feed intake and feed intake behaviour were obtained by electronic feed dispensers (ACEMO) under ad libitum conditions. Heritabilities of feed intake in periods 1 to 5 and over the entire test period were estimated to be 0.16, 0.24, 0.30, 0.27, 0.26, and 0.22, respectively. The maximum heritability of daily feed intake in the third time period on test corresponds to about 130 days of age at about 85 kg of weight. Daily feed intake in this period showed a high genetic correlation with the average feed intake over the whole performance test (rg = 0.91). Estimates of genetic correlations between daily feed intake and feed conversion ratio, residual feed intake, average daily gain or backfat thickness were 0.04, 0.97, 0.62 and 0.42, respectively. Boars feed intake activities decreased over time while time per day in the feeder was almost constant. Traits of feed intake behaviour as feeding rate, feed intake/visit, number of visits, time per visit, and time per day in the feeder showed high heritabilities of 0.44, 0.51, 0.43, 0.42, and 0.43, respectively, but genetic correlations with performance and carcass traits were generally low. One exception was the behavioural trait time per day in the feeder with its moderate genetic correlations to daily feed intake (rg = 0.44) and average daily gain on test (rg = 0.32). Selection for lean growth will improve lean growth feed efficiency as indicated by the negative correlation of −0.47. But more efficient may be the use of the component traits, lean content, daily feed intake and daily gain in particular of the most informative test period.