The influence of feeding behaviour on feed intake curve parameters and performance traits of station-tested boars

Abstract

The use of feed intake behaviour traits, obtained from electronic feeding stations, and feed intake curve parameters to genetically improve performance traits was analysed. Daily feed intake and feed intake behaviour of 5601 group-penned boars of two dam lines were recorded by electronic feeders in weeks 1, 3, 5, 7 and 9 during 10 weeks (100–170 d) on performance test. Additionally, performance test traits and parameters of an individually fitted linear-quadratic regression of feed intake on time on test, were available. A multiple trait animal model considering observed feed intake and feed intake behaviour at each test week as a different trait was used. Estimated heritabilities for feed intake and feed intake behaviour of the entire test period were 0.39, 0.46, 0.34, 0.44, 0.44 and 0.41 for daily feed intake, time per day, visits per day, time per visit, feed intake per visit, and feed intake rate, respectively. Heritabilities for behavioural traits in each test week were below estimates of entire test and showed lower variation, except for daily feed intake and time per day. Residual standard deviation of feed intake using linear-quadratic regression on time on test showed a moderate heritability of 0.22. Genetic correlations of feed intake behaviour traits indicate that number of visits per day was independent from growth performance, while time per day was genetically associated with average daily gain and daily feed intake (0.31 and 0.41). In contrast, visits per day and related traits such as time per visit and feed intake per visit were genetically correlated with residual standard deviation of linear-quadratic regression (−0.28, 0.31 and 0.39). Feed intake per visit in the seventh test week resulted in the highest genetic correlation (0.45) with residual standard deviation of the feed intake curve. This residual standard deviation and related traits will be of increasing interest for future breeding programs in order to obtain high performances in a wide range of environments.