Eating traits in relation to performance and carcass traits of restrictedly fed group-housed finishing pigs

Seventy-two crossbred barrows (28.7 +/- 0.3 kg live weight (LW)) were used to examine whether there is a relation between eating traits, and performance and carcass traits in ad libitum and restrictedly fed group-housed pigs. The experiment included two replicates, each consisting of 36 pigs. From day 1 to 42, all pigs were maintained with free access to a starter diet containing 12.7 MJ metabolizable energy (ME) and 8.2 g ileal apparent digestible lysine per kg. The experimental period was from day 42 (55.9 kg LW) to the end of the experiment (110.2 kg LW). The pigs in treatment I were maintained with free access to a high (H) energy diet (13.1 MI ME and 7.1 g ileal apparent digestible lysine per kg). For pigs in treatments 2 and 3 the daily energy allowance per pig was restricted to 18 MJ ME above the daily energy requirement for maintenance using diet H, and a low (L) energy diet (12.5 MI ME and 6.7 g ileal apparent digestible lysine per kg), respectively The weekly measured LW was used to compute the energy requirements for maintenance (M = 0.719 MJ ME X LW (kg)(0.63)). Daily food intake and eating traits per pig were determined using transponders and an electronic feeding station equipped with an antenna. Daily energy intake of the ad libitum and restrictedly fed pigs was correlated with growth and lean meat tissue content of the carcass. In the pigs given food ad libitum, daily energy intake was correlated with daily feeder visiting time, time per meal and food intake per meal, but not with number of meals per day and rate of food intake. In the restricted treatments, number of meals per day was correlated with energy intake, but not with lean tissue content of the carcass. In conclusion, number of meals per day explained part of the variation of lean tissue content of the carcass in ad libitum, but not in restrictedly fed group-housed pigs.