LAUSR

Abstract The objective of the study was to determine the physical-chemical composition of protein hydrolysates from meat by-products from poultry and swine processing, as well as to evaluate the apparent digestibility coefficients (ADC) of crude protein (ADCCB), crude energy (ADCCE), essential (ADCEAA), and non-essential (ADCNEAA) amino acids for juvenile Nile tilapia. The physicochemical composition (dry matter, crude protein, crude energy, essential and non-essential amino acids) of the hydrolyzed swine liver proteins (HSLP), porcine mucosa (HSMP), feathers (HFP) and chicken (HPP) was analyzed. Five diets were formulated, with one reference diet and four tests diets composed of 80% of the reference diet and 20% of hydrolyzed protein (HSLP, HSMP, HFP and HPP). For the apparent digestibility test, 500 juvenile Nile tilapia (69.08 ±0.69 g) were randomly distributed, 25 fish per tank adapted with a fecal collection cup. The animals were fed at a rate of 4% of live weight per day divided into five daily feedings, for a total of 30 days. The indirect method of feces collection was followed using 0.1% chromium oxide III (Cr2O3) as an inert marker. Significant differences were found between the ADCs of the different protein hydrolysates evaluated (p 0.05) to the ADCCP (97.12%) and ADCCE (96.62%) averages obtained for HSMP. In general, the averages of the ADCEAA; ADCNEAA for HSMP (98.59%) were higher than that observed in the HSLP group (90.54%; p