Effects of continuous and periodic feeding by electronic feeders on accuracy of measuring feed intake information and their genetic association with growth performances

Abstract

The objective of the study was to analyse the effects of different feeding and recording regimes by electronic feeding stations on growth rate, feed intake and feed intake behaviour. A total of 563 boars of three dam lines were group‐penned and fed ad libitum during an age‐dependent performance test. Of this total, 219 were fed during the entire performance test period of 10 weeks by electronic feeding stations (continuous feeding regime). Based on this feeding regime, no differences were found in feed intake and feed intake behaviour when considering information from either all weeks or every second week. A second group of 344 boars was fed during test weeks 1, 3, 5, 7 and 9 by electronic feeding stations and in the remaining weeks feed was supplied using conventional feeders without recording feed intake (periodic feeding regime). Growth rate and backfat thickness were non‐significantly different between feeding regimes, but significant differences were found between the periodic and continuous feeding regime in daily feed intake (2218 versus 2544 g) and behavioural traits such as visits per day (5.4 versus 7.2), time per day (57.1 versus 63.5 min), time per visit (12.5 versus 11.4 min), and feed intake rate (41.5 versus 43.4 g). Furthermore, the effect of test days on estimation of feed intake was analysed. In the periodic feeding regime, only the exclusion of the first 2 days of each week with recording showed a significant improvement of prediction of feed intake. Based on this daily information, differences in feed intake between feeding regimes decreased (2492 versus 2592 g), whereas visits per day, time per visit and feed intake per visit still differed significantly between periodic and continuous feeding regimes (5.7 versus 7.2; 13.5 versus 11.6 min; and 541 versus 467 g, respectively). Differences were also observed for genetic correlations among behavioural traits between the periodic and continuous feeding regimes, e.g. for daily feed intake and feed intake rate with time per visit (0.47 versus –0.07; –0.16 versus –0.57) and with feed intake per visit (0.81 versus 0.17; 0.58 versus –0.08). Based on the present results a continuous feeding regime was recommended in order to avoid the effect of repeated adaptation. This feeding regime also delivers a greater amount of reliable information and increases the accuracy of prediction of feed intake capacity. In case of limited test capacities and measuring feed intake in particular periods, the first two test days of each period with recording should be excluded to obtain more reliable feed intake information.