Effect of advancing the supply of finisher diet on growth performances and carcass and pork quality of heavy barrows and gilts

A total of 120 Durocx(Large WhitexLandrace) pigs, 50% barrows and 50% gilts, with 54.1 +/- 0.14 kg BW and 103 +/- 3 days of age, were used to study the effect of advancing the shift to a standard finisher feed from 100 to 90 and 80 kg BW on production performances and carcass and pork quality. Each of the six treatments (two sexesxthree BWs at time of feeding shift) was replicated four times and the experimental unit was the pen (with five pigs for growth performance and carcass variables and three pigs for pork and fat traits). The grower (163 g CP and 9.5 g total Lys/kg) and the finisher diets (152 g CP and 7.9 g total Lys/kg) were based on maize, barley and vegetal protein concentrates, contained 13.39 MJ metabolizable energy/kg and were offered ad libitum through the trial. Pigs intended for dry-cured product elaboration were slaughtered at 170 +/- 3 days of age as average (124 and 115 kg BW for barrows and gilts, respectively). For the overall period, barrows ate more feed (P < 0.001) and grew faster (P = 0.03) than gilts. No effect of feed shift was observed on growth performances, although the average daily CP intake (P = 0.01) and feeding costs (P=0.04) were reduced by advancing the transition to the finisher feed. Carcasses from barrows were heavier (P < 0.001) and had wider backfat depth (P < 0.001) than those from gilts but no significant differences were observed in the meat chemical composition. The feed change schedule did not modify carcass or meat traits. It is concluded that an early shift to the finisher feed (at 80 kg BW instead of 100 kg BW) might be an interesting strategy in pigs intended for dry-cured products because, although it neither increased body fatness nor improved pork quality, CP intake and feeding costs were reduced without impairment of growth performances. Results were similar for barrows and gilts.