Genetic associations between observed feed intake measurements during growth, feed intake curve parameters and growing–finishing performances of central tested boars

Abstract

Optimization of growing–finishing performance can be reached by increasing feed intake capacity of pigs at an early stage of growth and by limiting feed intake at the end of the finishing period. Daily feed intake recorded by electronic feeder and other growth performances were obtained from 5601 group-penned nucleus boars of two dam lines on a central test station. A multiple trait animal model was used which considers the observed feed intake at each test week as a different trait. Estimated heritabilities for feed intake were 0.12, 0.23, 0.29, 0.39, 0.32 and 0.39 for the first, third, fifth, seventh, and ninth test week, and entire test period, respectively. A linear regression and a linear-quadratic regression were fitted for daily feed intake as functions of time. Heritabilities of the function parameters ranged between 0.11 and 0.32. Average estimated feed intake and average change in daily feed intake (slope) were obtained for five periods (12 days) based on linear-quadratic regression. Heritabilities for average estimated feed intake changed from 0.17, 0.32, 0.37, 0.43 to 0.41 and the slope of feed intake from 0.18, 0.21, 0.33, 0.27 to 0.22 with time on test. Genetic correlations of observed feed intake among different periods were substantially different from one (0.02–0.73) which indicates that feed intake was differently genetically determined during growth. In order to account for the different genetic relationships of feed intake during performance test and their influence on other performance traits, a multiple trait animal model using average estimated feed intake of each period, slope of the first three periods, and all genetic associations among these traits, were recommended to improve feed efficiency and lean growth.