Control of individual daily growth in group housed pigs using feeding stations.

In this thesis, it was examined whether it is possible to control individual daily growth and carcass composition in group-housed pigs using feeding stations. A forelegs weighing system to estimate the daily individual body weight (BW) of group-housed pigs was developed and validated. In two experiments, BW dependent feeding strategies in the finishing period were examined in relation to performance and carcass traits. In Exp. 1, the daily energy allowance of barrows was restricted to 18 MJ ME per day above maintenance. In Exp. 2, barrows were restricted to a feeding level at which their growth was similar to the mean growth of a group of ad libitum fed gilts. In Exp. 1, feed restriction improved lean meat tissue percentage with 2.6 units. In Exp. 2, feed restriction resulted in a similar growth as the ad libitum fed gilts, but gave no improvement of the lean meat tissue percentage. In both experiments, feed restriction decreased the between animal variance in energy intake, but not in energy conversion ratio, growth or lean meat tissue percentage. In addition to energy intake, carryover effects from the growing period and number of meals per day of ad libitum fed pigs explained part of the variance in lean meat tissue percentage. In conclusion, feeding stations and forelegs weighing devices can be used to control individual daily growth and carcass traits of group-housed pigs. However, the variance in performance and carcass traits was not only related to the variance in energy intake