Levels of chromium-nicotinic acid in diets for growing-finishing pigs

Ninety-six barrows and gilts (Landrace x Large White x Duroc), with average initial weight of 25.93+/-0.57 kg, were used in order to evaluate the effe cts of Cr on performance and carcass characteristics, in a random block des ign, according to a 6 x 2 factorial arrangement (6 Cr levels x 2 sexes). A basal diet (0 ppb Cr) was supplemented with 100, 200, 300, 400 e 500 ppb Cr , as Cr-nicotinic acid, added to the vitamin premix. On the 70(th) day of t he experimental period, all animals were weighted, slaughtered and had thei r carcass evaluated using Hennessy probe and the Brazilian Carcass Classifi cation Method. There was a significant sex effect (P<0.006) on all the stud ied variables, except loin eye area and loin deepness. Cr level in diet did not show any effect of the performance or carcass variables (P>0.05). The addition of up to 500 ppb Cr in the diet, in the form of Cr-nicotinic acid, did not improve performance and carcass traits of growing-finishing pigs.