Efeito do peso ao abate nos rendimentos dos processamentos do pacu (Piaractus mesopotamicus)

The objective was to evaluate the effect of slaughter weight on the processing efficiency of Pacu (Piaractus mesopotamicus).The fish were cultivated in a soil vivarium and fed commercial feed. After ten months of cultivation, 96 fish were deadened, slaughtered, weighed and dissected to determine the yield of clean body, fillet and percentage of entrails. The weight classes analyzed were: CI - 135 to 285g; CII - 310 to 385g; CIII - 400 to 585g; CIV - 600 to 1.285g. For the variance analysis the data was grouped in four weight classes, and the regression equations were estimated regarding mean weight in each class. No effect of the weight class (P>0,05) was observed on the yield of clean body (RTL). However, there was a linear effect (P<0,05) of the weight classes in slaughter over the fillet yield (RF) and percentage of entrails. Pacus slaughtered in more elevated weight classes had greater filled yield. Thus, the fish destined to the fillet process should preferably be slaughtered at higher weights. The fish cultivated with the objective of being commercialized as a carcass or whole with entrails removed may be slaughtered at lower weights.