Farinha de mexilhão dourado com diferentes granulometrias na alimentação de frangos de corte

Abstract

The present study aimed to evaluate the effects of different particle sizes of golden mussel meal (GMM) in replacement of limestone in broiler diets at 21 and 42 days of age on performance, blood parameters, bone quality and carcass yield. Two experiments have been carried out using a completely randomized design, as follows: in the first experiment, 1,100 male broilers were used and in the second, 750 male broilers, which were distributed in five treatments with 10 replications. The treatments consisted of a control diet using limestone (381 µm) and GMM in different particle sizes (302, 380, 451 and 549 μm). From 20 to 40 days, the blood samples were collected for serum parameters analysis. The performance was evaluated from 21 to 42 days and, after slaughter, bones (tibia and femur) samples were collected for bone quality analysis. No significant differences (P>0.05) were observed in performance from 1 to 21 and 21 to 42 days when limestone was replaced by GMM. There was an increasing linear response in alkaline phosphatase (AP) concentration (P=0.0048) at 20 days. At 40 days, were observed a quadratic effect (P=0.032) for aspartate aminotransferase (AST), with the minimum response value in the particle size of 337 µm, and decreasing linear effect in Ca (P=0.031). In addition, the GMM 380 μm (P=0.032) caused a lower concentration compared to the control diet. For the other blood parameters (ALT, P and GGT) measured at 20 and 40 days, no difference was observed (P>0.05). For quality bone parameters at 21 days, a reduction (P=0.0005) in femur bone strength was observed in the GMM 451 µm compared to control diet. But at 42 days, no interference (P>0.05) for femur and for tibia was observed. At 21 days, for femur, a quadratic effect (P=0.032) was observed in Ca percentage, with the minimum response value in the particle size of 427 µm, and a reduction (P=0.017) on P percentage. Compared to control diet, there were a lower percentage of Ca (P=0.068) and P (P=0.017) for GMM 451 µm on femur and, on tibia, a greater (P=0.049) percentage of P for GMM 549 µm. At 42 days, no differences (P>0.05) were observed for Ca and P percentage on femur and tibia, however, compared to control diet, there was a reduction (P=<0.0001) of mineral matter percentage of GMM using 380, 451 and 549 µm. The performance during the initial, growing and final phases were not affected, as well as carcass and cut yields at 42 days were not affected (P>0.05) by different GMM particle sizes in limestone replacement. It was concluded that, regardless of the particle size used, GMM did not affect the performance, carcass and cuts yield, blood parameters and bone quality, and is therefore recommended in diets for broilers from 1 to 21 and 21 to 42 days of age up to particle sizes of 549 µm (sieve 8 mm), ensuring a profitable destination for the mollusk and reducing grinding and production costs.